List of Abbreviations
WHO – World Health Organization
ISUOG – International Society of Ultrasound in Obstetrics and Gynecology
CDC – consultation and diagnostic center
CS – cesarean section
MRI – magnetic resonance imaging
MR – pelvimetry – magnetic resonance pelvimetry
EFW – estimated fetal weight
Ultrasound – ultrasound examination
Terms and Definitions
Cephalic presentation – the fetus's head is located over the pelvic inlet of the mother and is the first part to pass through the birth canal.
Flexion cephalic presentation – the fetal head is in a flexed position at the mother's pelvic inlet. Depending on whether the occiput rotates anteriorly or posteriorly, anterior or posterior varieties of flexion cephalic presentation are distinguished.
Extension cephalic presentation – the fetal head is in an extended position at the mother's pelvic inlet. Depending on the degree of extension, brow, face, or sinciput presentation develops.
Anatomically contracted pelvis – a pelvis in which at least one of its external dimensions is reduced by 1.5–2 cm compared to normal [1]. The possibility of spontaneous delivery depends on the degree and shape of pelvic contraction.
Clinically (functionally) contracted pelvis (fetopelvic disproportion, cephalopelvic disproportion) – the inability of the fetus to progress through the birth canal due to a mismatch between the dimensions of the fetus and the mother's pelvis.
Macrosomia (large for gestational age) – fetal body weight of 4000 grams or more
External pelvimetry – measurement of the external dimensions of the pelvis
MR pelvimetry – magnetic resonance pelvimetry, measurement of the pelvic cavity dimensions using magnetic resonance imaging.
[1] Management of pregnancy and childbirth in women with an anatomically contracted pelvis // Information Letter of the Russian Ministry of Health. – 2002
1. Brief information on the disease or condition
1.1 Definition of the disease or condition
Fetopelvic disproportion – an imbalance between the dimensions of the fetal presenting part and the mother's pelvis that prevents its progression through the birth canal.
Sinciput presentation – a variant of fetal cephalic presentation formed as a result of slight head extension. In this case, the leading point is the area of the large fontanelle, and the plane of the largest circumference of the head passes through the direct size (12 cm).
Brow presentation – a variant of fetal cephalic presentation formed as a result of moderate head extension. In this case, the leading point is the superciliary arch, and the plane of the largest circumference passes through the large oblique diameter (13 cm).
Face presentation – a variant of fetal cephalic presentation formed as a result of maximal head extension. In this case, the leading point is the chin, and the plane of the largest circumference of the head passes through the vertical diameter (9.5 cm).
1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)
Fetopelvic disproportion occurs during labor due to reduced dimensions of the bony pelvis (anatomically contracted pelvis), excessively large fetal dimensions, unfavorable engagement of the presenting part, or a combination of these factors. The character of uterine activity is also of great importance.
Any reduction in pelvic dimensions can lead to the development of a clinically contracted pelvis [1].
The antenatal period, childhood, and puberty are of great significance in pelvic formation [2]. In the antenatal period, abnormal pelvic formation may occur as a result of metabolic disorders (especially mineral metabolism) between the mother and the fetus. An important role is played by the pregnant woman's diet, which exhibits an imbalance of vitamins and trace elements [3]. In the neonatal period and early childhood, inadequate feeding, poor living conditions, inadequate nutrition, rickets, heavy child labor, infectious diseases (bone tuberculosis, poliomyelitis), and injuries to the pelvis, spine, or lower extremities can cause abnormal pelvic formation [4], [5]. During puberty, changes in pelvic structure may be caused by significant emotional and physical stress, stressful situations, intensive sports training, acceleration factors, hormonal imbalance, and the irrational choice of constantly worn footwear [6], [7]. Maternal height reflects the nutritional status of individuals since childhood; deviations in it are observed if the woman suffered from rickets or osteomyelitis in childhood. Pregnancy in adolescence also causes problems because the bony pelvis has not yet completed its formation [8].
Short stature, a decrease in the intertrochanteric diameter of the pelvis, the transverse and longitudinal dimensions of the lumbosacral Michaelis rhombus, and the ratio of the pregnant woman's height to the uterine fundal height = less than 4.7 are significantly more common in clinically contracted pelvis [9], [10], [11], [12], [13]. Therefore, their measurement is used as a screening method in its prediction [14], [15]. Computed tomography data have shown that women with a reduced pelvic outlet anteroposterior diameter and a narrow pubic angle have an increased risk of obstructed labor requiring operative delivery [16]. In modern clinical practice, magnetic resonance pelvimetry, which does not involve radiation exposure, is used as an additional objective method for assessing pelvic cavity dimensions [17], [18].
Another possible cause of fetopelvic disproportion is extension presentation of the fetal head, which occurs in 1% of deliveries [19].
Extension presentations of the fetal head are most commonly caused by [19]:
■ anatomical pelvic contraction (especially flat pelvis);
■ large fetus or fetal growth restriction;
■ decreased uterine tone and coordination disorders of labor;
■ short umbilical cord;
■ decreased tone of the anterior abdominal wall muscles;
■ decreased tone of the pelvic floor muscles;
■ fetal thyroid tumor;
■ stiffness of the fetal atlantooccipital joint
Since the mid-1970s, an increase in fetal birth weight has been observed [20], [21]. Notably, over the past 30 years, a 15–25% increase in the incidence of macrosomia has been noted, occurring in 5–20% of births [22], significantly increasing the probability of fetopelvic disproportion during labor.
1.3 Epidemiology of the Disease or Condition
Fetopelvic disproportion occurs in 1.3–17% of deliveries and is associated with an increased rate of operative delivery, perinatal and maternal morbidity and mortality [23], [24], [25], [26].
Anatomical pelvic contraction increases the probability of fetopelvic disproportion by 2.8 times [27]. According to external obstetric pelvimetry, an anatomically contracted pelvis occurs in 1.04–7.7% of observations. Frequency of various degrees of pelvic contraction: grade I pelvic contraction – 96.8%; grade II pelvic contraction – 3.18%; grade III pelvic contraction – 0.02%.
In recent years, there has been a change in the structure of anatomically contracted pelves with a decrease in the frequency of classic forms with marked contraction and an increase in mild or erased forms [2], [6], [23].
1.4 Features of Coding the Disease or Condition
O33 Maternal care for known or suspected disproportion
O33.0 Maternal care for disproportion due to deformity of maternal pelvic bones
O33.1 Maternal care for disproportion due to uniformly contracted pelvis
O33.2 Maternal care for disproportion due to inlet contraction of pelvis
O33.3 Maternal care for disproportion due to outlet contraction of pelvis
O33.4 Maternal care for disproportion of mixed maternal and fetal origin
O33.5 Maternal care for disproportion due to unusually large fetus
O33.6 Maternal care for disproportion due to fetal hydrocephalus
O33.8 Maternal care for disproportion of other origin
O33.9 Maternal care for disproportion, unspecified
O65 Obstructed labor due to maternal pelvic abnormality
O65.0 Obstructed labor due to deformed pelvis
O65.1 Obstructed labor due to uniformly contracted pelvis
O65.2 Obstructed labor due to pelvic inlet contraction
O65.3 Obstructed labor due to pelvic outlet and midcavity contraction
O65.4 Obstructed labor due to fetopelvic disproportion, unspecified
O65.5 Obstructed labor due to abnormality of maternal pelvic organs
O65.8 Obstructed labor due to other maternal pelvic abnormalities
O65.9 Obstructed labor due to maternal pelvic abnormality, unspecified
O32.3 Maternal care for face, brow and chin presentation
O64.2 Obstructed labor due to face presentation
O64.3 Obstructed labor due to brow presentation
1.5 Classification of the disease or condition
Classification of contracted pelvis and fetal head extension presentations
From the standpoint of pelvic capacity as the basis of the birth canal, the following are distinguished [28]:
Normal pelvis
Borderline pelvis
Contracted pelvis
There is currently no single universally accepted classification of anatomically contracted pelves. A contracted pelvis is usually classified by shape, degree of contraction, and frequency of occurrence.
Caldwell-Moloy classification of contracted pelvis by shape (1933, 1934) [29], [30]
Gynecoid
Anthropoid
Android
Platypelloid
Mixed shape
Classification by shape and frequency of occurrence [23]
A. Common forms of contracted pelvis
1) transverse-contracted pelvis (45.2%);
2) flat pelvis: simple flat pelvis - Litzmann/Naegele (13.6%), rachitic flat pelvis (6.5%), pelvis with a reduced anteroposterior diameter of the wide part of the pelvic cavity (21.8%);
3) generally equally contracted pelvis (8.5%).
Rare forms of contracted pelvis (4.4%)
1) obliquely displaced and obliquely contracted pelvis;
2) pelvis contracted by exostoses, bone tumors resulting from displaced pelvic fractures;
3) other forms of pelvis (assimilation, funnel-shaped, kyphotic, osteomalacic, spondylolisthetic, split, or anteriorly open pelvis).
4) pelvis contracted due to ovarian or uterine tumors located partially or completely within the pelvic cavity.
A.F. Palmov's classification of anatomically contracted pelves by degree of contraction [31]
Grade I: true conjugate 10.5 - 9.1 cm (96.8%);
Grade II: 9.0 - 7.6 cm (3.18%);
Grade III: 7.5 - 6.6 cm (0.02%);
Grade IV: less than 6.5 cm (0.0%).
The degree of contraction of a transverse-contracted pelvis is determined by the transverse diameter of the pelvic inlet plane [32]:
Grade I contraction - transverse diameter of the inlet 12.5 - 11.5 cm;
Grade II contraction - transverse diameter 11.4 - 10.5 cm;
Grade III contraction - transverse diameter of the inlet less than 10.5 cm.
1.6 Clinical presentation of the disease or condition
Anatomical pelvic contraction usually does not present distinct clinical symptoms. A contracted pelvis should be suspected in short women (under 155-160 cm) with a shoe size under 23 (EU 36); with a pointed (in primiparae) or pendulous (in multiparae) abdominal shape at term [33], [34], [35].
A clinically contracted pelvis should be suspected in the presence of prolonged labor; expulsive contractions while the fetal head is located above the narrow part of the pelvic cavity; unfavorable fetal head engagement; excessive or, conversely, absent cranial bone molding at the end of the first or second stage of labor; development of edema of the cervical lips, vulvar, and perineal tissues; and difficulty urinating [1], [36], [37], [38].
2. Diagnostics, medical indications and contraindications for diagnostic methods
The diagnosis of an anatomically contracted pelvis is established based on physical and instrumental examination results, usually during pregnancy. The diagnosis of a clinically contracted pelvis is established during labor based on signs of fetopelvic disproportion.
2.1 Complaints and Anamnesis
It is recommended to take a history and clinical background in accordance with the clinical guidelines "Normal Pregnancy" and "Normal Labor" to identify risk factors and symptoms of fetopelvic disproportion [39].
GCP CLEL 5Level of Evidence C (Level of Likelihood of Evidence - 5).
2.2 Physical Examination
It is recommended to perform a physical examination during labor in accordance with the clinical guidelines "Normal Labor" to diagnose complications [40].
GCP CLEL 5Level of Evidence C (Level of Likelihood of Evidence - 5).
Comments: examination in accordance with the recommendations will help identify deviations from the normal course of labor, indicating the need for further evaluation to rule out developing fetopelvic disproportion.
It is recommended to assess the type of presentation and the degree of fetal head flexion in the active phase of the first and/or second stage of labor to assess the risk and detect fetopelvic disproportion [41], [42], [43].
LoE CGoE 3Level of Evidence C (Grade of Recommendation - 3).
Comment: occiput posterior and deflexion presentations of the fetus carry an increased risk of a difficult course of the 1st and 2nd stages of labor due to the larger head circumference passing through the birth canal. During labor, these presentation types are associated with longer first and second stages of labor, oxytocin infusion, epidural analgesia, chorioamnionitis, operative vaginal delivery, third- and fourth-degree perineal lacerations, cesarean section, postpartum hemorrhage, and infections. Newborns more frequently have low Apgar scores at 1 minute. In occiput posterior presentation, the chances of spontaneous vaginal delivery for primiparae are only 26% and for multiparae 57% [41], [44], [45].
It is recommended to determine the estimated fetal weight to predict fetopelvic disproportion during labor [1], [46].
GPP BLE 2Grade of Recommendations B (Level of Evidence 2).
Comment: macrosomia is a risk factor due to the large fetal head circumference [1] passing through the birth canal. Macrosomia increases the risk of fetopelvic disproportion by 3-4 times and increases the rate of birth trauma [47] (clavicle or humeral fracture, obstetric palsy, asphyxia). The most common maternal complications are postpartum hemorrhage, perineal trauma, or uterine atony [48], [49], [50].
It is recommended to consider the duration of labor and altered uterine contractility at the end of the first and second stages of labor as a possible sign of developing fetopelvic disproportion [51], [52].
GPP BLE 2Grade of Recommendations B (Level of Evidence 2).
Comments: The duration of labor is usually the result of the interaction of various factors: gestational age, fetal size and maternal pelvic dimensions, characteristics of presentation engagement, parity, and pain relief. Currently, the recommended time limits for the second stage of labor, depending on parity and pain relief, are: 3 hours for primiparous women without epidural analgesia and 4 hours with epidural analgesia; for multiparous women - 2 hours and 3 hours, respectively [52]. Slowing of labor (cervical dilation/head descent) accompanied by vigorous, often expulsive uterine contractions or, conversely, uterine inertia, is often a symptom of fetopelvic disproportion [53], [54].
It is recommended to perform a vaginal examination in case of deviation from the normal course of labor at the end of the first or second stage to identify signs of fetopelvic disproportion [55], [56].
GCP CLEL 5Level of Evidence C (Level of Likelihood of Evidence - 5).
Comment: in case of deviations from the normal course of labor (change in uterine activity, signs of fetal distress, difficulty urinating/hematuria, edema of the external genitalia, etc.), it is necessary to assess the degree of cervical dilation and the condition of its margins, station, type of presentation and fetal head engagement characteristics, cranial bone molding, and the severity of the caput succedaneum for timely diagnosis of fetopelvic disproportion [55], [57], [58].
2.3 Laboratory Diagnostics
Not applicable
2.4 Instrumental Diagnostics
It is recommended to perform MRI pelvimetry for women who, based on a consultative examination at the consultation and diagnostic center of a tertiary obstetric hospital, have indications for clarifying pelvic dimensions to choose the mode of delivery [17], [18], [59].
GCR BLEL 3Recommendation Grade B (Level of Evidence — 3).
Comment: MRI pelvimetry is a radiation-free, objective method for assessing pelvic cavity dimensions. Furthermore, the degree of pelvic reduction according to MRI data is inversely proportional to the rate of cesarean section, operative vaginal deliveries, and perineal trauma [60], [61]. The use of MRI pelvimetry is advisable in the risk group; indications for its performance are determined based on the results of a clinical examination (see appendix). Routine use of MRI is not recommended, as it is not a screening method for identifying women requiring pre-labor surgical delivery [62].
If there is difficulty determining the station, type, and position of the fetal head during labor, fetal ultrasound is recommended to diagnose unfavorable head engagements [63], [64].
LeveL of Recommendation BGrade of Evidence 2LeveL of Recommendation B (Grade of Evidence - 2).
Comment Deflexion presentations or asynclitic engagements of the fetal head account for one-third of the total incidence of all cesarean sections. The diagnosis is traditionally established by vaginal examination during labor; however, the use of ultrasound increases diagnostic accuracy and aids in choosing obstetric management [65], [66].
It is recommended to use fetal ultrasound to assess head descent and predict labor outcomes when clinical data regarding the development of fetopelvic disproportion during labor are doubtful [64], [67].
LeveL of Recommendation BGrade of Evidence 2LeveL of Recommendation B (Grade of Evidence - 2).
Comment: when clinical assessment of the dynamics of fetal head descent during labor is difficult, the use of ultrasound criteria allows for an objective assessment of the probability of vaginal delivery [68]. Ultrasound criteria for assessing head descent are presented in Appendix B2.
2.5 Other Procedures
Not applicable.
3. Treatment, including drug and non-drug therapies, diet therapy, and pain management
3.1 Non-pharmacological treatments.
Pregnant women identified through clinical examination and external pelvimetry as having a high risk of fetopelvic disproportion during labor should be referred to a level III obstetric inpatient consultation and diagnostic department for a consultative decision regarding the need for further evaluation, planning the place and mode of delivery [1]
Comment: consultation of a pregnant woman in the consultation and diagnostic department aims to clarify the likelihood of an adverse labor outcome, and when indicated, perform additional diagnostic tests (MRI pelvimetry), and determine the obstetric hospital and method of delivery.
If the fetus is in a persistent occiput posterior position or deflexion head presentation during labor, the woman should be allowed to move freely or change body position to facilitate spontaneous engagement of the fetal head in a normal position. [69]
GCR BLOE 3Grade of Recommendation B (Level of Evidence 3).
Comment: if an unfavorable variant of fetal head presentation develops at the end of the first and beginning of the second stage of labor without signs of fetal or maternal distress, positional therapy increases the likelihood of establishing an occiput anterior presentation [70]. In the absence of specific factors (pelvic shape and dimensions, excessive labor stimulation, premature pushing, etc.), spontaneous rotation of the fetus into the occiput anterior presentation is observed in 90% of cases.
Manual rotation of the fetal head from the occiput posterior to the occiput anterior position for the prevention of fetopelvic disproportion is not recommended [71], [72], [73].
Level of Evidence (LoE) 1Grade of Recommendation (GoE) A (Level of Evidence: 1).
Comments: Currently, there is no evidence that prophylactic manual rotation of the fetal head from the posterior to the anterior position reduces the rate of operative delivery [74], [75]. In the absence of fetal head descent in the second stage of labor and persistence of the occiput posterior position, manual rotation of the fetal head from the posterior to the anterior position may be performed (see Appendix B4).
3.2 Medical treatments.
Not applicable.
3.3 Surgical treatments.
In cases of fetopelvic disproportion, emergency cesarean section is recommended to prevent severe maternal and perinatal morbidity and mortality [23], [76].
GCP CLEL 5Level of Evidence C (Level of Likelihood of Evidence - 5).
Comment: fetopelvic disproportion causes severe debilitating and fatal complications that can be avoided by timely delivery via cesarean section.
[1] Order of the Russian Ministry of Health No. 1130n dated October 20, 2020, "On approval of the Procedure for providing medical care in the field of 'obstetrics and gynecology'"
4. Medical Rehabilitation and Sanatorium-Resort Treatment
Not applicable.
5. Prevention and Dispensary Observation
Specific prevention does not exist.
Induction of labor at term is recommended to reduce perinatal complications and the cesarean section rate in accordance with the guidelines "Failed induction of labor (cervical preparation for labor and labor induction)" [77], [78]
Level of Evidence (LoE) 1Grade of Recommendation (GoE) B (Level of Evidence: 1).
Comment: Induction of labor at term, compared to expectant management, is associated with a reduction in perinatal mortality and the number of cesarean sections, although it may be associated with an increased rate of instrumental vaginal deliveries.
At the same time, compared to expectant management, labor induction in the presence of an increased risk of complications due to the disproportion between maternal pelvic dimensions and fetal size is associated with a reduction in infant complications without increasing the rate of cesarean sections or operative vaginal deliveries [79], [80].
6. Organization of Medical Care
Provision of medical care to women with an anatomically contracted pelvis on a elective basis is carried out in level II or III obstetric hospitals based on routing schemes approved by regional health authorities.
The choice of the method of delivery and the timing of hospitalization is determined by the attending physician.
When urgent and emergency indications for delivery via cesarean section arise, the surgery is performed in the hospital where the patient is located at the time of diagnosis, provided that the necessary medical equipment and personnel are available to care for the mother and newborn, or the patient is transported to a level II or III obstetric hospital provided that transportation is feasible and there are no contraindications to
transportation on the part of the patient. Transportation of patients with established emergency and urgent indications for delivery via cesarean section is carried out by medical transport accompanied by medical personnel.
7. Additional Information
Not applicable
Criteria for Evaluating the Quality of Medical Care
№ | Quality criterion | Evaluation of compliance |
|---|---|---|
1 | Estimated fetal weight calculated | Yes/No |
2 | External pelvimetry performed | Yes/No |
3 | Evaluation of presentation type and degree of fetal head flexion performed by vaginal examination in the active phase of the 1st stage and/or 2nd stage | Yes/No |
4 | Emergency cesarean section performed upon establishing the diagnosis of clinical fetopelvic disproportion | Yes/No |
References
Show references
Maharaj D. Assessing Cephalopelvic Disproportion: Back to the Basics. Obstet Gynecol Surv. 2010; 65(6):387–95.
Pavličev M., Romero R., Mitteroecker P. Evolution of the human pelvis and obstructed labor: new explanations of an old obstetrical dilemma. Am J Obstet Gynecol. 2020; 222(1):3–16.
Milman N., Paszkowski T., Cetin I., Castelo-Branco C. Supplementation during pregnancy: beliefs and science. Gynecol Endocrinol. 2016; 32(7):509–16.
DeSilva J.M., Rosenberg K.R. Anatomy, Development, and Function of the Human Pelvis. Anat Rec. 2017; 300(4):628–32.
Gruss L.T., Schmitt D. The evolution of the human pelvis: changing adaptations to bipedalism, obstetrics and thermoregulation. Philos Trans R Soc B Biol Sci. 2015; 370(1663):20140063.
Huseynov A., Zollikofer C.P.E., Coudyzer W., Gascho D., Kellenberger C., Hinzpeter R., et al. Developmental evidence for obstetric adaptation of the human female pelvis. Proc Natl Acad Sci. 2016; 113(19):5227–32.
Sheliia G.P., Chavchidze A.T. [Features of physical and sexual development and reproductive behaviour in female adolescents]. Georgian Med News. 2012; (202):28–32.
Konje J.C., Ladipo O.A. Nutrition and obstructed labor. Am J Clin Nutr. 2000; 72(1):291S-297S.
Malonga F.K., Mukuku O., Ngalula M.T., Luhete P.K., Kakoma J.-B. Étude anthropométrique et pelvimétrique externe chez les nullipares de Lubumbashi: facteurs de risque et score prédictif de la dystocie mécanique. Pan Afr Med J. 2018; 31.
Bansal S., Guleria K., Agarwal N. Evaluation of Sacral Rhomboid Dimensions to Predict Contracted Pelvis: A Pilot Study of Indian Primigravidae. J Obstet Gynecol India. 2011; 61(5):523–7.
Connolly G., McKenna P. Maternal height and external pelvimetry to predict cephalo-pelvic disproportion in nulliparous African women. BJOG An Int J Obstet Gynaecol. 2001; 108(3):338–338.
Rozenholc A., Ako S., Leke R., Boulvain M. The diagnostic accuracy of external pelvimetry and maternal height to predict dystocia in nulliparous women: a study in Cameroon. BJOG An Int J Obstet Gynaecol. 2007; 114(5):630–5.
Liselele H.B., Boulvain M., Tshibangu K.C., Meuris S. Maternal height and external pelvimetry to predict cephalopelvic disproportion in nulliparous African women: a cohort study. BJOG An Int J Obstet Gynaecol. 2000; 107(8):947–52.
Liselele H.B., Boulvain M., Tshibangu K.C., Meuris S. Maternal height and external pelvimetry to predict cephalopelvic disproportion in nulliparous African women: a cohort study. BJOG An Int J Obstet Gynaecol. 2000; 107(8):947–52.
Liselele H.B., Tshibangu C.K., Meuris S. Association between external pelvimetry and vertex delivery complications in African women. Acta Obstet Gynecol Scand. 2000; 79(8):673–8.
Frémondière P., Thollon L., Adalian P., Delotte J., Marchal F. Which Foetal-Pelvic Variables Are Useful for Predicting Caesarean Section and Instrumental Assistance. Med Princ Pract. 2017; 26(4):359–67.
von Bismarck A., Ertl-Wagner B., Stöcklein S., Schöppe F., Hübener C., Hertlein L., et al. MR Pelvimetry for Breech Presentation at Term- Interobserver Reliability, Incidental Findings and Reference Values. Rofo. 2019; 191(5):424–32.
Trufanov G.E., Shmedyk N.Yu., Vikhtinskaya I.A., Ryazanov V.V., Schmidt A.A., Ipatov V.V., et al. Magnetic resonance pelvimetry: diagnosis of the risk of clinically contracted pelvis and shoulder dystocia at the end of the third trimester of pregnancy. Problems of Women's Health. 2014; 9(1):44–51.
Obstetrics: National Guidelines / ed. by G. M. Savelieva, G. T. Sukhikh, V. N. Serov, V. E. Radzinsky. - 2nd ed., revised and expanded. Moscow: GEOTAR-Media; 2018. 1088 p.
Glinianaia S. V, Rankin J., Pless-Mulloli T., Pearce M.S., Charlton M., Parker L. Temporal changes in key maternal and fetal factors affecting birth outcomes: A 32-year population-based study in an industrial city. BMC Pregnancy Childbirth. 2008; 8(1):39.
Zhang J., Landy H.J., Ware Branch D., Burkman R., Haberman S., Gregory K.D., et al. Contemporary Patterns of Spontaneous Labor With Normal Neonatal Outcomes. Obstet Gynecol. 2010; 116(6):1281–7.
Henriksen T. The macrosomic fetus: a challenge in current obstetrics. Acta Obstet Gynecol Scand. 2008; 87(2):134–45.
Chernukha, E.A., Volobuev, A.I., Puchko T.K. Anatomically and clinically contracted pelvis. 2005. 253 p.
A. A. Incidence, causes, and maternofetal outcomes of obstructed labor in Ethiopia: systematic review and meta-analysis Reprod Health. 2021; 18:61.
Shimelis Fantu , Hailemariam Segni F. Incidence, causes and outcome of obstructed labor in jimma university specialized hospital. Ethiop J Heal Sci. 2010; 20(3):145–51.
Tewodros Eshete Wonde A.M. Maternofetal outcomes of obstructed labor among women who gave birth at general hospital in Ethiopia. BMC Res Notes. 2019; 12(12(1)):128.
Abraham W., Berhan Y. Predictors of labor abnormalities in university hospital: unmatched case control study. BMC Pregnancy Childbirth. 2014; 14:256.
Suonio S., Saarikoski S., Räty E., Vohlonen I. Clinical assessment of the pelvic cavity and outlet. Arch Gynecol. 1986; 239(1):11–6.
Longo L.D. Classic pages in obstetrics and gynecology. Anatomical variations in the female pelvis and their effect in labor with a suggested classification. William Edgar Caldwell and Howard Carmen Moloy. American Journal of Obstetrics and Gynecology, vol. 26, pp. 4. Am J Obstet Gynecol. 1977; 127(7):798.
Caldwell W.E., Moloy H.., D’Esopo D.A. Further Studies on the Peilvic Architecture**Read at a meeting of the New York Obstetrical, Society, March 13, 1934. Am J Obstet Gynecol. 1934; 28(4):482–97.
A.F. P. Management of labor in contracted pelvis. Perm. 1929. 67 p.
Kalganova R.I., Ch.V.N. On the issue of diagnostics of transversely constricted pelvis. AkushGinek. 1978; :53–6.
Payne P.R. Cephalopelvic Disproportion. Trop Doct. 1997; 27(3):129–30.
Arendt E., Singh N.S.C., Oona M.R. Effect of maternal height on caesarean section and neonatal mortality rates in sub-Saharan Africa: An analysis of 34 national datasets. Bhutta ZA, editor. PLoS One. 2018; 13(2):e0192167.
Alijahan R., Kordi M., Poorjavad M., Ebrahimzadeh S. Diagnostic accuracy of maternal anthropometric measurements as predictors for dystocia in nulliparous women. Iran J Nurs Midwifery Res. 2014; 19(1):11–8.
L.N. V. Clinically contracted pelvis. Medical Journal. 2011; 1(35):133-135.
Chernukha E.A., A.E.V. Diagnosis and management of labor in anatomically and clinically contracted pelvis. Handbook for Feldsher and Midwife. 2016; 6:25–32.
Stewart K.S., Philpott R.H. FETAL RESPONSE TO CEPHALOPELVIC DISPROPORTION*. BJOG An Int J Obstet Gynaecol. 1980; 87(8):641–9.
Clinical guideline "Normal pregnancy", Russian Society of Obstetricians and Gynecologists, approved by the Scientific and Practical Council of the Russian Ministry of Health, 2022.
Clinical guideline "Singleton delivery, spontaneous delivery in occipital presentation (normal labor)", Russian Society of Obstetricians and Gynecologists, approved by the Scientific and Practical Council of the Russian Ministry of Health, 2022.
PONKEY S. Persistent fetal occiput posterior position: obstetric outcomes. Obstet Gynecol. 2003; 101(5):915–20.
SIZER A. Occipitoposterior position: associated factors and obstetric outcome in nulliparas. Obstet Gynecol. 2000; 96(5):749–52.
Cheng Y.W., Cheng Y.W., Shaffer B.L., Caughey A.B. Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001. J Matern Neonatal Med. 2006; 19(9):563–8.
SIZER A. Occipitoposterior position: associated factors and obstetric outcome in nulliparas. Obstet Gynecol. 2000; 96(5):749–52.
Cheng Y.W., Cheng Y.W., Shaffer B.L., Caughey A.B. Associated factors and outcomes of persistent occiput posterior position: A retrospective cohort study from 1976 to 2001. J Matern Neonatal Med. 2006; 19(9):563–8.
Tomić V., Bošnjak K., Petrov B., Đikić M., Knežević D. Macrosomic Births at Mostar Clinical Hospital: A 2-Year Review. Bosn J Basic Med Sci. 2007; 7(3):271–4.
Mikulandra , M Perisa E.S. When is fetal macrosomia (> or = 4500 g) an indication for caesarean section? Zentralbl Gynakol. 1996; (118(8)):441–7.
Mahony R., Walsh C., Foley M.E., Daly L., O’Herlihy C. Outcome of Second Delivery After Prior Macrosomic Infant in Women With Normal Glucose Tolerance. Obstet Gynecol. 2006; 107(4):857–62.
Tomić V., Bošnjak K., Petrov B., Đikić M., Knežević D. Macrosomic Births at Mostar Clinical Hospital: A 2-Year Review. Bosn J Basic Med Sci. 2007; 7(3):271–4.
Feinstein U., Sheiner E., Levy A., Hallak M., Mazor M. Risk factors for arrest of descent during the second stage of labor. Int J Gynecol Obstet. 2002; 77(1):7–14.
Piper J.M., Bolling D.R., Newton E.R. The second stage of labor: Factors influencing duration. Am J Obstet Gynecol. 1991; 165(4):976–9.
Cheng Y.W., Caughey A.B. Defining and Managing Normal and Abnormal Second Stage of Labor. Obstet Gynecol Clin North Am. 2017; 44(4):547–66.
Sheiner E., Levy A., Feinstein U., Hershkovitz R., Hallak M., Mazor M. Obstetric risk factors for failure to progress in the first versus the second stage of labor. J Matern Neonatal Med. 2002; 11(6):409–13.
Althaus J.E., Petersen S., Driggers R., Cootauco A., Bienstock J.L., Blakemore K.J. Cephalopelvic disproportion is associated with an altered uterine contraction shape in the active phase of labor. Am J Obstet Gynecol. 2006; 195(3):739–42.
Stewart K.S., Philpott R.H. FETAL RESPONSE TO CEPHALOPELVIC DISPROPORTION*. BJOG An Int J Obstet Gynaecol. 1980; 87(8):641–9.
Debby A., Rotmensch S., Girtler O., Sadan O., Golan A., Glezerman M. Clinical significance of the floating fetal head in nulliparous women in labor. J Reprod Med. 2003; 48(1):37–40.
Debby A., Rotmensch S., Girtler O., Sadan O., Golan A., Glezerman M. Clinical significance of the floating fetal head in nulliparous women in labor. J Reprod Med. 2003; 48(1):37–40.
Browne M.A., Crump P., Niven S.J., Teuten E., Tonkin A., Galloway T., et al. Accumulation of Microplastic on Shorelines Woldwide: Sources and Sinks. Environ Sci Technol. 2011; 45(21):9175–9.
Franz M., von Bismarck A., Delius M., Ertl-Wagner B., Deppe C., Mahner S., et al. MR pelvimetry: prognosis for successful vaginal delivery in patients with suspected fetopelvic disproportion or breech presentation at term. Arch Gynecol Obstet. 2017; 295(2):351–9.
Spörri S., Thoeny H.C., Raio L., Lachat R., Vock P., Schneider H. MR imaging pelvimetry: a useful adjunct in the treatment of women at risk for dystocia? AJR Am J Roentgenol. 2002; 179(1):137–44.
Keller T.M., Rake A., Michel S.C.A., Seifert B., Efe G., Treiber K., et al. Obstetric MR pelvimetry: reference values and evaluation of inter- and intraobserver error and intraindividual variability. Radiology. 2003; 227(1):37–43.
Zaretsky M. V., Alexander J.M., McIntire D.D., Hatab M.R., Twickler D.M., Leveno K.J. Magnetic Resonance Imaging Pelvimetry and the Prediction of Labor Dystocia. Obstet Gynecol. 2005; 106(5, Part 1):919–26.
Bellussi F., Ghi T., Youssef A., Salsi G., Giorgetta F., Parma D., et al. The use of intrapartum ultrasound to diagnose malpositions and cephalic malpresentations. Am J Obstet Gynecol. 2017; 217(6):633–41.
Molina F.S., Nicolaides K.H. Ultrasound in labor and delivery. Fetal Diagn Ther. 2010; 27(2):61–7.
Ghi T., Bellussi F., Pilu G. Sonographic diagnosis of lateral asynclitism: a new subtype of fetal head malposition as a main determinant of early labor arrest. Ultrasound Obstet Gynecol. 2015; 45(2):229–31.
Eggebø T.M., Hassan W.A., Salvesen K., Torkildsen E.A., Østborg T.B., Lees C.C. Prediction of delivery mode by ultrasound-assessed fetal position in nulliparous women with prolonged first stage of labor. Ultrasound Obstet Gynecol. 2015; 46(5):606–10.
Dall’Asta A., Angeli L., Masturzo B., Volpe N., Schera G.B.L., Di Pasquo E., et al. Prediction of spontaneous vaginal delivery in nulliparous women with a prolonged second stage of labor: the value of intrapartum ultrasound. Am J Obstet Gynecol. 2019; 221(6):642.e1-642.e13.
Malvasi A., Stark M., Ghi T., Farine D., Guido M., Tinelli A. Intrapartum sonography for fetal head asynclitism and transverse position: sonographic signs and comparison of diagnostic performance between transvaginal and digital examination. J Matern Fetal Neonatal Med. 2012; 25(5):508–12.
Yang L., Yi T., Zhou M., Wang C., Xu X., Li Y., et al. Clinical effectiveness of position management and manual rotation of the fetal position with a U-shaped birth stool for vaginal delivery of a fetus in a persistent occiput posterior position. J Int Med Res. 2020; 48(6):300060520924275.
Yang L., Yi T., Zhou M., Wang C., Xu X., Li Y., et al. Clinical effectiveness of position management and manual rotation of the fetal position with a U-shaped birth stool for vaginal delivery of a fetus in a persistent occiput posterior position. J Int Med Res. 2020; 48(6):300060520924275.
Marguier Blanchard I., Metz J.-P., Eckman Lacroix A., Ramanah R., Riethmuller D., Mottet N. Rotation manuelle des variétés postérieures : état des lieux de la littérature en 2019. Gynécologie Obs Fertil Sénologie. 2019; 47(9):672–9.
Phipps H., de Vries B., Hyett J., Osborn D.A. Prophylactic manual rotation for fetal malposition to reduce operative delivery. Cochrane database Syst Rev. 2014; (12):CD009298.
Marguier Blanchard I., Metz J.-P., Eckman Lacroix A., Ramanah R., Riethmuller D., Mottet N. [Manual rotation in occiput posterior position: A systematic review in 2019]. Gynecol Obstet Fertil Senol. 2019; 47(9):672–9.
Phipps H., de Vries B., Hyett J., Osborn D.A. Prophylactic manual rotation for fetal malposition to reduce operative delivery. Cochrane database Syst Rev. 2014; (12):CD009298.
Marguier Blanchard I., Metz J.-P., Eckman Lacroix A., Ramanah R., Riethmuller D., Mottet N. [Manual rotation in occiput posterior position: A systematic review in 2019]. Gynecol Obstet Fertil Senol. 2019; 47(9):672–9.
Wu J.M., Williams K.S., Hundley A.F., Connolly A., Visco A.G. Occiput posterior fetal head position increases the risk of anal sphincter injury in vacuum-assisted deliveries. Am J Obstet Gynecol. 2005; 193(2):525–9.
Middleton P., Shepherd E., Morris J., Crowther C.A., Gomersall J.C. Induction of labour at or beyond 37 weeks’ gestation. Cochrane database Syst Rev. 2020; 7:CD004945.
Clinical guidelines "Failed induction of labor (cervical preparation for labor and labor induction)", Russian Society of Obstetricians and Gynecologists, approved by the Scientific and Practical Council of the Russian Ministry of Health, 2022.
Boulvain M., Irion O., Dowswell T., Thornton J.G. Induction of labour at or near term for suspected fetal macrosomia. Cochrane database Syst Rev. 2016; (5):CD000938.
Magro-Malosso E.R., Saccone G., Chen M., Navathe R., Di Tommaso M., Berghella V. Induction of labour for suspected macrosomia at term in non-diabetic women: a systematic review and meta-analysis of randomized controlled trials. BJOG. 2017; 124(3):414–21.
Ghi T., Eggebø T., Lees C., Kalache K., Rozenberg P., Youssef A., et al. ISUOG Practice Guidelines: intrapartum ultrasound. Ultrasound Obstet Gynecol. 2018; 52(1):128–39.
Bychenko V.G., Kulabukhova E.A., Baev O.R., Babich D.A. Magnetic resonance pelvimetry. Obstetrics and Gynecology. 2021; 9:152–60.
Blasi I., D’Amico R., Fenu V., Volpe A., Fuchs I., Henrich W., et al. Sonographic assessment of fetal spine and head position during the first and second stages of labor for the diagnosis of persistent occiput posterior position: a pilot study. Ultrasound Obstet Gynecol. 2010; 35(2):210–5.
Dall’Asta A., Rizzo G., Masturzo B., Di Pasquo E., Schera G.B.L., Morganelli G., et al. Intrapartum sonographic assessment of the fetal head flexion in protracted active phase of labor and association with labor outcome: a multicenter, prospective study. Am J Obstet Gynecol. 2021; 225(2):171.e1-171.e12.
Vitner D., Paltieli Y., Haberman S., Gonen R., Ville Y., Nizard J. Prospective multicenter study of ultrasound-based measurements of fetal head station and position throughout labor. Ultrasound Obstet Gynecol. 2015; 46(5):611–5.
Broberg J.C., Caughey A.B. A randomized controlled trial of prophylactic early manual rotation of the occiput posterior fetus at the beginning of the second stage vs expectant management. Am J Obstet Gynecol MFM. 2021; 3(2):100327.
Reichman O., Gdansky E., Latinsky B., Labi S., Samueloff A. Digital rotation from occipito-posterior to occipito-anterior decreases the need for cesarean section. Eur J Obstet Gynecol Reprod Biol. 2008; 136(1):25–8.
Le Ray C., Serres P., Schmitz T., Cabrol D., Goffinet F. Manual rotation in occiput posterior or transverse positions: risk factors and consequences on the cesarean delivery rate. Obstet Gynecol. 2007; 110(4):873–9.
Barth W.H. Persistent occiput posterior. Obstet Gynecol. 2015; 125(3):695–709.
Methodological letter of the Russian Ministry of Health No. 15-4/I/2-2570 dated March 4, 2020, "Resuscitation and stabilization of newborns in the delivery room".
Appendix A1. Working Group Composition
Oleg R. Bayev – MD, PhD, Professor, Honored Doctor of the Russian Federation, Head of the Delivery Department, Head of the Department of Innovative Technologies, Head of the Department of Obstetrics and Gynecology at the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Natalia V. Dolgushina – MD, PhD, Professor, Deputy Director – Head of the Department of Scientific Activity Organization at the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health, Chief freelance specialist of the Russian Ministry of Health on women's reproductive health (Moscow). No conflict of interest.
Roman G. Shmakov - MD, PhD, Professor of the Russian Academy of Sciences, Director of the Institute of Obstetrics at the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health, Chief freelance specialist of the Russian Ministry of Health in obstetrics (Moscow). No conflict of interest.
Vladimir G. Bychenko – Head of the Department of Diagnostic Radiology at the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Leila V. Adamyan – Academician of the Russian Academy of Sciences, MD, PhD, Professor, Deputy Director of the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health, Chief freelance specialist of the Russian Ministry of Health in gynecology (Moscow). No conflict of interest.
Natalia V. Artymuk - MD, PhD, Professor, Head of the Department of Obstetrics and Gynecology named after Professor G.A. Ushakova, Kemerovo State Medical University of the Russian Ministry of Health, Chief freelance specialist in obstetrics and gynecology of the Russian Ministry of Health in the Siberian Federal District (Kemerovo). No conflict of interest.
Bashmakova Nadezhda Vasilievna – MD, PhD, Professor, Chief Researcher, Ural Research Institute of Maternal and Infant Care of the Russian Ministry of Health, Chief Freelance Specialist of the Russian Ministry of Health in Obstetrics and Gynecology in the Ural Federal District (Yekaterinburg). No conflict of interest.
Bezhenar Vitaly Fedorovich - MD, PhD, Professor, Head of the Clinic of Obstetrics and Gynecology, Head of the Department of Obstetrics, Gynecology and Neonatology, Head of the Department of Obstetrics, Gynecology and Reproductology, First Saint Petersburg State Medical University named after Academician I.P. Pavlov of the Russian Ministry of Health, Chief Freelance Specialist in Obstetrics and Gynecology of the Russian Ministry of Health in the Northwestern Federal District (Saint Petersburg). No conflict of interest.
Belokrinitskaya Tatyana Evgenyevna – MD, Professor, Honored Doctor of the Russian Federation, Head of the Department of Obstetrics and Gynecology at the Faculty of Advanced Training and Professional Retraining of Healthcare Personnel, Chita State Medical Academy of the Russian Ministry of Health, Chief freelance specialist in obstetrics and gynecology of the Russian Ministry of Health in the Far Eastern Federal District (Chita). No conflict of interest.
Volochaeva Maria Vyacheslavovna – PhD, physician at the 1st Maternity Ward, researcher at the Department of Innovative Technologies, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Desyatnik Kirill Aleksandrovich – obstetrician-gynecologist at the Organizational and Methodological Department, Yekaterinburg Clinical Perinatal Center. No conflict of interest.
Karapetyan Anna Ovikovna – PhD in Medical Sciences, Assistant Professor at the Department of Obstetrics and Gynecology, obstetrician-gynecologist of the 1st Maternity Ward, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Krasnopolsky Vladislav Ivanovich - Academician of the RAS, MD, Professor, President of the Moscow Regional Research Institute of Obstetrics and Gynecology (Moscow). No conflict of interest.
Victoria A. Krutova – D.Sc. (Medicine), Professor, Chief Physician of the Clinic, Vice-Rector for Clinical Work at the Kuban State Medical University of the Russian Ministry of Health, Chief freelance specialist in obstetrics and gynecology of the Russian Ministry of Health in the Southern Federal District (Krasnodar). No conflict of interest.
Malyshkina Anna Ivanovna – MD, Professor, Director of the V.N. Gorodkov Ivanovo Research Institute of Motherhood and Childhood of the Russian Ministry of Health, Chief freelance specialist in obstetrics and gynecology of the Russian Ministry of Health in the Central Federal District (Ivanovo). No conflict of interest.
Martirosyan Sergey Valeryevich – PhD, Chief Physician of the Yekaterinburg Clinical Perinatal Center, Associate Professor at the Department of Obstetrics and Gynecology, Faculty of General Medicine and Prophylaxis, Ural State Medical University (Yekaterinburg). No conflict of interest.
Anton V. Mikhailov – Professor, Chief freelance specialist in obstetrics and gynecology of the Healthcare Committee of Saint Petersburg, Chief Physician of Saint Petersburg State Budgetary Healthcare Institution "Maternity Hospital No. 17". No conflict of interest.
Perevozkina Olga Vladimirovna – PhD, Head of the Organizational and Methodological Department, Yekaterinburg Clinical Perinatal Center. No conflict of interest.
Vasily A. Petrukhin – D.Sc. (Medicine), Professor, Honored Doctor of the RF, Director of the Moscow Regional Research Institute of Obstetrics and Gynecology (Moscow). No conflict of interest.
Prikhodko Andrey Mikhailovich – PhD, Senior Researcher, physician at the 1st Maternity Ward, Assistant at the Department of Obstetrics and Gynecology, National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Viktor E. Radzinsky - Corresponding Member of the RAS, D.Sc. (Medicine), Professor, Head of the Department of Obstetrics and Gynecology with a Course in Perinatology, Peoples' Friendship University of Russia (Moscow). No conflict of interest.
Galina M. Savelieva – Academician of the RAS, D.Sc. (Medicine), Professor, Honored Scientist, Head of the Department of Obstetrics and Gynecology, Pediatric Faculty, Pirogov Russian National Research Medical University (Moscow). No conflict of interest.
Vladimir N. Serov – Academician of the RAS, D.Sc. (Medicine), Professor, Honored Scientist of the RF, President of the Russian Society of Obstetricians and Gynecologists, Chief Researcher at the National Medical Research Center for Obstetrics, Gynecology and Perinatology named after Academician V.I. Kulakov of the Russian Ministry of Health (Moscow). No conflict of interest.
Ildar F. Fatkullin – D.Sc. (Medicine), Professor, Head of the Prof. V.S. Gruздеv Department of Obstetrics and Gynecology, Kazan State Medical University, Chief freelance specialist of the Russian Ministry of Health in obstetrics and gynecology in the Volga Federal District (Kazan). No conflict of interest.
Filippov Oleg Semenovich – MD, Professor, Honored Doctor of the Russian Federation, Professor at the Department of Obstetrics and Gynecology, Faculty of Postgraduate Training of Physicians, A.I. Yevdokimov Moscow State University of Medicine and Dentistry of the Russian Ministry of Health (Moscow). No conflict of interest.
Appendix A2. Methodology for Developing Clinical Guidelines
Target audience for these clinical guidelines:
1. obstetrician-gynecologists
2. obstetrics and gynecology residents
3. radiologists
4. radiology residents
Table 1. Level of Evidence (LoE) grading scale for diagnostic methods (diagnostic interventions)
LoE | Definition |
|---|---|
1 | Systematic reviews of studies with reference standard control or systematic reviews of randomized controlled trials with meta-analysis |
2 | Individual studies with reference standard control or individual randomized controlled trials and systematic reviews of studies of any design, except randomized controlled trials, with meta-analysis |
3 | Studies without consecutive reference standard control or studies with a reference standard not independent of the test method, or non-randomized comparative studies, including cohort studies |
4 | Non-comparative studies, case report |
5 | There is only a rationale for the mechanism of action or expert opinion |
Table 2. Level of Evidence (LoE) grading scale for prevention, treatment, and rehabilitation methods (preventive, therapeutic, and rehabilitative interventions)
LoE | Definitions |
|---|---|
1 | Systematic review of RCTs with meta-analysis |
2 | Individual RCTs and systematic reviews of studies of any design except RCTs, with meta-analysis |
3 | Non-randomized comparative studies, including cohort studies |
4 | Non-comparative studies, case reports or case series, case-control studies |
5 | Only justification of the mechanism of action of the intervention (preclinical studies) or expert opinion is available |
Table 3. Grade of Recommendation (GoR) scale for prevention, diagnostic, treatment, and rehabilitation methods (preventive, diagnostic, therapeutic, and rehabilitative interventions)
GoR | Definition |
|---|---|
A | Strong recommendation (all considered efficacy criteria (outcomes) are important, all studies are of high or acceptable methodological quality, and their conclusions on the outcomes of interest are consistent) |
B | Conditional recommendation (not all considered efficacy criteria (outcomes) are important, not all studies are of high or acceptable methodological quality, and/or their conclusions on the outcomes of interest are inconsistent) |
C | Weak recommendation (lack of adequate quality evidence (all considered efficacy criteria (outcomes) are unimportant, all studies are of low methodological quality, and their conclusions on the outcomes of interest are inconsistent) |
Appendix A3. Reference Materials
Related documents
Clinical guidelines "Singleton birth, spontaneous delivery in occipital presentation (normal labor)"
Clinical guidelines "Normal pregnancy"
Clinical guidelines "Failed induction of labor (Cervical preparation for labor and labor induction)"
ACOG Fetal Macrosomia (Replaces Practice Bulletin Number 22, November 2000) (Reaffirmed 2018)
Guidelines for Perinatal Care. 8th Edition. ACOG&AAP, 2017.
Guidelines for Perinatal Care. 8th Edition. ACOG&AAP, 2017
ACOG Practice Bulletin Number 49, December 2003: Dystocia and Augmentation of Labor
Managing complications in pregnancy and childbirth: a guide for midwives and doctors – 2nd ed. ISBN 978-92-4-156549-3 © World Health Organization 2017
ACOG technical bulletin. Dystocia and the augmentation of labor. Number 218--December 1995 (replaces no. 137, December 1989, and no. 157, July 1991). American College of Obstetricians and Gynecologists. Int J Gynaecol Obstet. 1996; 53(1):73–80.
Middleton P, Shepherd E, Crowther CA. Induction of labour for improving birth outcomes for women at or beyond term. Cochrane Database of Systematic Reviews 2018, Issue 5. Art. No.: CD004945. DOI: 10.1002/14651858.CD004945.pub4.
Appendix B. Physician Action Algorithms
Appendix B1. Physician Action Algorithms
*
expulsive uterine contractions with the fetal head located above the narrow cavity of the pelvis
weakened or hypertonic uterine activity
sharply pronounced pain of contractions
positive Vasthout's sign
Zangemeister's sign
arrest of cervical dilation progress near complete dilation
edema of the cervix, vagina, and subsequently external genitalia
unfavorable variants of head engagement (pronounced asynclitism, posterior asynclitism, posterior face presentation, extension presentation)
excessively pronounced cranial bone molding or its absence
pronounced caput succedaneum
lack of fetal head progression at full cervical dilation and satisfactory uterine activity
pronounced symptoms of bladder compression – absence of spontaneous urination in the parturient woman, admixture of blood in the urine
anxiety in the parturient woman's behavior, confusion
symptoms of threatened uterine rupture (high-standing retraction ring on the uterus)
Diagnosis of fetopelvic disproportion during labor is one of the most difficult in obstetrics, as the clinical picture lacks specific manifestations in the early stages. When a clinically narrow pelvis develops, there is a gradual progression of the clinical picture with the onset of symptoms.
The diagnosis of a clinically narrow pelvis is established based on a combination of 2–3 or more signs identified during monitoring and examination. The range of manifestations of a clinically narrow pelvis depends on many factors (anthropometric data, parity, fetal size, duration of labor and uterine activity patterns, analgesia features, etc.) and varies widely.
Among the initial signs, one should note the arrest of cervical dilation or head progression, unfavorable head engagement, Vasthout's and Zangemeister's signs, and specific features of cranial bone molding. Signs of threatened uterine rupture are late manifestations.
Appendix B2 Ultrasound examination technique for determining the level, station, presentation type, position, and progression of the fetal head during labor.
For ultrasound examination during labor, a convex transducer with a frequency of 3.5–7.0 MHz is used. Patient examination is performed in B-mode. Transabdominal and transperineal scanning (transducer positioned in the sagittal plane below the pubic symphysis between the labia majora) are used. The study is performed after bladder emptying with the patient in the supine position. Anatomical landmarks are used, and the occipito-vertebral angle and angle of progression are calculated (Tables 1, 2, 3, 4).
Table 1. Ultrasound signs of anterior and posterior occipital presentations, transverse position of the sagittal suture.
Clinical situation | Ultrasound signs |
|---|---|
Anterior occipital presentation | Transabdominal scanning:
|
Posterior occipital presentation | Transabdominal scanning:
Transperineal scanning:
|
Transverse position of the sagittal suture | Transabdominal scanning:
Transperineal scanning:
|
Table 2. Ultrasound signs of extension presentations
Clinical situation | Ultrasound signs |
|---|---|
Sincipital | Transabdominal scanning:
Transperineal scanning:
|
Brow | Transabdominal scanning:
Transperineal scanning:
|
Face presentation | Transabdominal scanning:
Transperineal scanning:
|
Table 3. Ultrasound signs of asynclitic engagement
Clinical situation | Ultrasound signs |
|---|---|
Anterior asynclitism | Transabdominal scanning:
Transperineal scanning:
|
Posterior asynclitism | Transabdominal scanning:
Transperineal scanning:
|
Asynclitism (lateral) | Transabdominal scan
Transperineal scanning:
|
Table 4. Ultrasound parameters of fetal head position and descent in labor.
Value | Measurement |
|---|---|
Transperineal longitudinal scan | |
Angle of progression | The angle between the pubic symphysis and a vector drawn from the lower edge of the pubic symphysis tangent to the fetal head. When the angle of progression is greater than 120°, 90% of deliveries end spontaneously. An angle of progression of 138° corresponds to the head position in the narrow cavity of the pelvis [68], [68]. |
Direction of fetal head movement (determined by transabdominal sagittal scan) | The angle between the longitudinal axis of the fetal head and the longitudinal axis of the mother's body. If this angle is ≥30°, the head vector is directed upwards, less than 0° – downwards, and for intermediate values, the direction is considered horizontal. When the head vector is directed upwards and its largest circumference is located at or below the level of the ischial spines, the probability of vaginal delivery is high. A head vector directed downwards indicates a head position above this level [81]. |
Transperineal transverse examination | |
Perineal distance | The shortest distance between the perineum and the contour of the fetal head [57]. A perineal distance of less than 4.5 cm with a decreasing trend over time indicates a high probability of vaginal delivery |
Angle of rotation | The angle between the direct diameter of the pelvis and the midline of the fetal head If the angle of rotation is less than 45°, the head position is at the level of "+2" or lower. If the angle of rotation is greater than 45° or the midline of the fetal head is not visualized, the head position is above "+2". An angle of rotation of less than 45° is sufficient for successful vacuum extraction of the fetus. |
Appendix B3. Technique of pelvimetry using pelvic magnetic resonance imaging.
MR pelvimetry is a safe and effective method for measuring internal pelvic dimensions, which does not involve ionizing radiation and allows for the diagnosis of anatomically narrow pelvis.
To diagnose anatomical pelvic constriction, magnetic resonance imaging is performed using MR scanners with a field strength of 1 to 3 T [82]. The examination is carried out according to the following protocol (Table 1). Recommended timing: II–III trimester of pregnancy, optimally after 36 weeks. To reduce scanning time, single-shot fast spin-echo (SSFSE, HASTE) sequences must be used. The duration of the study is 5–10 minutes. The results of the study provide the obtained internal pelvic dimensions, fronto-occipital and biparietal diameters of the fetal head, as well as the detection of signs of symphysitis, exostoses, consequences of traumatic injuries to the pelvic bones, coccyx and their deformation, and idiopathic fractures of the sacral lateral masses.
Table 1. Scanning protocol for performing MR pelvimetry
Sequence | Slice orientation | Slice thickness, mm | Matrix | Field of view | Acquisition time | |
|---|---|---|---|---|---|---|
1 | Loc (slice planning sequence) | In 3 mutually perpendicular planes | 5-8 | Not applicable | 300-400 mm | 10-30 sec |
2 | SSFSE/HASTE T2W | sagittal | 3-4 | 320 x 320 and higher | 320-400 mm | 30-50 sec |
3 | SSFSE/HASTE T2W | Oblique (pelvic inlet plane) | 3-4 | 320 x 320 and higher | 320-400 mm | 30-50 sec |
4 | SSFSE/HASTE T2W Fat Saturation | Oblique (plane of the pubic symphysis) | 3-4 | 320 x 320 and higher | 320-400 mm | 30-50 sec |
5 | SSFSE/HASTE T2W | Oblique (sagittal relative to the fetal head) | 3 | 320 x 320 and higher | 320-360 mm | 20-40 sec |
6 | SSFSE/HASTE T2W | Oblique (axial relative to the fetal head) | 3 | 320 x 320 and higher | 320-360 mm | 20-40 sec |
MR pelvimetry procedure:
1. Patient positioning: the patient is placed in the supine position, with a 15-degree tilt to the right side in the third trimester to prevent inferior vena cava compression, and secured using rolls and cushions. A surface coil is placed over the area of interest, positioning the center of the coil over the region of interest. If the patient is unable to lie supine, the examination may be performed in a lateral decubitus position (forced position). Centering is performed at the center of the coil to achieve optimal scanning conditions.
2. The examination begins with a scout program to plan subsequent sequences. The scout program acquires images in three orthogonal planes and serves solely for planning purposes.
3. T2-weighted images (SSFSE/HASTE) in the sagittal plane (relative to the body axes), slice thickness 3–4 mm, square matrix of at least 320 x 320, field of view 320–400 mm (Fig. 3). Sagittal tomograms are used to measure the direct pelvic diameters: pelvic inlet, wide part of the pelvic cavity, narrow part of the pelvic cavity, pelvic outlet (distance from the lower edge of the pubic symphysis to the coccyx), coccyx length and deformity, and sacral curvature. All measurements are performed on the mid-sagittal slice passing through the pubic symphysis.
4. T2WI (SSFSE/HASTE) in the oblique transverse plane (pelvic inlet plane), slice thickness 3–4 mm, square matrix of at least 320 x 320, field of view 300–340 mm. Tomograms are positioned as shown in Fig. 1 using the acquired sagittal slices parallel to the linea innominata. The acquired tomograms are used to measure the transverse dimensions of the pelvis: maximum inlet diameter, maximum diameter of the wide part, interspinous diameter, and bituberal diameter (Fig. 4).
5. When performing the examination after 36 weeks, the pubic symphysis must be assessed using T2WI (SSFSE/HASTE) with fat suppression. If widening of the pubic symphysis, cartilage edema, irregularity of the contours of the pubic surfaces, erosions, or areas of bone marrow edema in the adjacent surfaces of the pubic symphysis (exhibiting high MR signal intensity) are detected, a diagnosis of symphysitis is established (Fig. 3). Slice thickness should be 3–4 mm, square matrix at least 320 x 320, field of view 300–340 mm. Tomograms are positioned as shown in Fig. 5 using previously acquired sagittal and oblique slices.
6. To assess fetal head dimensions, a T2WI (SSFSE/HASTE) program oriented along the axial plane of the head is performed, measuring the fronto-occipital and biparietal diameters (Fig. 6). The obtained measurements can be verified by acquiring additional slices in the frontal and sagittal planes (relative to the head). Slice thickness should be 3 mm, square matrix at least 320 x 320, field of view 320–360 mm. Tomograms are positioned using previously acquired slices.
Figure 3. A. T2-weighted MRI in the sagittal plane; the dashed line indicates the required slice orientation for imaging along the plane of the pelvic inlet. B. T2-weighted MRI in the sagittal plane, showing the main dimensions: 1 - transverse diameter of the broad part, 2 - transverse diameter of the narrow part, 3 - anteroposterior diameter of the pelvic outlet.
Figure 4. T2WI in the oblique plane. A – maximum inlet diameter (distance between the most distant points of the pelvic brim). B – transverse diameter of the wide part of the cavity (diameter of the pelvic cavity lying on the line passing through the centers of the femoral heads). C – interspinous diameter or transverse diameter of the narrow part of the pelvic cavity (distance between the tips of the ischial spines). D – bituberal diameter or transverse diameter of the outlet (distance between the tuberosities of the ischial bones)
Figure 5. A – T2WI in the sagittal plane. The dashed line indicates the planning of the slice planes for assessing the condition of the pubic symphysis. B – T2WI with fat suppression of the MR signal through the symphyseal plane. Increased MR signal intensity from the cartilage due to edema is noted – a sign of symphysitis.
Figure 6. A – T2WI in the sagittal plane, dashed lines indicate the slice positioning plane for measuring the fetal head. B – T2WI performed in the oblique plane according to the anatomical landmarks of the fetal head. Lines show examples of measuring the fronto-occipital and biparietal diameters.
Based on the examination results, the radiologist fills out the table of obtained pelvic dimensions (Table 2), comparing the obtained values with the reference values (provided in Table 2). The physician also indicates the presence or absence of signs of symphysitis (after 36 weeks) and the fetal head dimensions (recommended after 38 weeks). Typical forms of anatomical pelvic contraction depending on changes in dimensions are given in Table 3.
Table 2. Sample table of pelvic dimensions indicating the lower limit of normal
Pelvic dimensions | |||
|---|---|---|---|
Direct: | Transverse: | ||
Pelvic inlet | (N = 11 cm) | Maximum inlet | (N = 12.5 cm) |
Wide part | (N = 12.5 cm) | Wide part of the cavity | N = 12.5 cm) |
Narrow part | (N = 11 cm) | Interspinous | (N = 10.5 cm) |
Outlet | (N = 9.5 cm) | Bituberal | (N = 11.5 cm) |
Coccyx length | |||
Table 3. Typical forms of anatomical pelvic contraction
Pelvic shape | Direct dimensions | Transverse dimensions: | |||||
|---|---|---|---|---|---|---|---|
inlet | wide part | outlet | inlet | wide part | interspinous | bituberal | |
Transversely contracted pelvis: a) transversely contracted pelvis with increased direct dimensions b) transversely contracted pelvis with an increased direct dimension of the wide part of the cavity c) transversely contracted pelvis with shortening of the interspinous dimension | 12,5 11,5 11,7 | 13,7 11,9 12,4 | 13,0 11,6 11,8 | 12,4 12,2 13,2 | 11,7 11,6 12,6 | 10,1 10,2 10,1 | 11,3 10,8 11,4 |
Flat pelvis: a) simple flat pelvis b) rachitic flat pelvis c) pelvis with shortening of the direct dimension of the wide part of the cavity | 10,4 10,4 11,5 | 11,6 12,8 11,7 | 11,5 12,1 11,8 | 13,7 13,1 13,6 | 13,2 12,5 12,9 | 11,6 10,7 11,4 | 12,4 11,2 12,2 |
Generally evenly contracted pelvis | 11,0 | 12,1 | 11,8 | 12,0 | 11,5 | 10,2 | 10,8 |
Indications for magnetic resonance pelvimetry (indications are relative and applied taking into account the clinical situation based on the results of a consultative examination at the consultative and diagnostic center of a level 3 obstetric hospital):
1. High risk of perinatal pathology: multiparous women with a complicated course and unfavorable outcome of previous births (operative vaginal delivery, intraoperative fetal death, birth trauma, impaired neurological status in the infant, or early neonatal mortality of term infants resulting from birth trauma);
2. Reduction of external pelvic dimensions by more than 1.5–2 cm, history of pelvic trauma, previous rickets and poliomyelitis, congenital hip dislocation.
3. Signs of developing fetopelvic disproportion: unstable lie, oblique lie, breech presentation of the fetus (if there is no other cause: polyhydramnios, uterine malformation, uterine myoma).
4. Symphysiopathy, separation of the pubic bones.
MR pelvimetry may also be performed in the postpartum period (clinically narrow pelvis, birth trauma, prolonged labor, etc.)
Contraindications for MRI examination.
Absolute contraindications:
1. Presence of a pacemaker or other electronic implantable devices (middle ear implant system, insulin pump, etc.)
2. Presence of ferromagnetic foreign bodies (e.g., a fragment inside or near the eyeball, cerebral vessel clips, etc.).
It should be noted that today there are specific models of the above-mentioned devices (pacemaker, clips) that are specially designed and tested in a strong magnetic field, and performing an MRI with these models is possible.
The remaining contraindications are relative and include:
1. Pregnancy in the first trimester
2. Presence of implanted metal devices and structures (osteosynthesis systems, artificial heart valves, joint prostheses, vena cava filters, etc.). Most such products manufactured today are made of non-magnetic alloys and cannot harm the patient's health during the scan. However, if the patient has implanted metal structures or devices, a consultation with a radiologist is necessary. The final decision on whether the scan can be performed is made by the radiologist based on the medical documentation from the implant manufacturer.
Appendix B4. Manual rotation of the fetal head
Manual rotation of the fetal head is an obstetric procedure during which the physician rotates the fetal head from the occipitoposterior position to the occipitoanterior position during labor.
Currently, the occipitoposterior position at the beginning of the second stage of labor is not considered an indication for manual rotation to the anterior position, which is more favorable regarding labor outcomes. Ultrasound studies show that in 25–33% of cases, the fetus is in the posterior position at the start of labor, but in 84–89% of cases, spontaneous rotation to the anterior position occurs during the biomechanism of labor [83], [84], [85].
As a result, the incidence of delivery with the fetal head in the posterior position does not exceed 5–7%.
At the same time, studies indicate a shortening of the 2nd stage of labor and a decrease in the rate of operative deliveries with "prophylactic" manual rotation of the fetal head from the posterior to the anterior position at the beginning of the 2nd stage of labor [86], [87], [87].
According to Le Ray et al. (2007), the failure rate of manual fetal head rotation is 9.7%, but it is three times higher when attempting rotation before full cervical dilation and four times higher when attempted in the setting of labor arrest [88].
W.H. Barth uses the following approach to manage women in labor with the occipitoposterior position of the fetus [89]:
· waiting for natural progress from the moment of full cervical dilation for 1 hour in nulliparous women, 30 minutes in multiparous women without epidural analgesia, and 1 hour 30 minutes and 1 hour, respectively, with epidural analgesia
· in the absence of head descent despite adequate uterine contractile activity, there are three management options: operative delivery by Cesarean section, expectant management, or manual fetal head rotation followed by operative vaginal delivery.
In cases of fetal macrosomia, a fetal head station above the broad part of the pelvic cavity (higher than level +1/5), and an android pelvis shape (narrow pubic arch, flattened sacrum, short sacrospinous ligament extending from the lower sacral and upper coccygeal vertebrae to the ischial spine), Cesarean section should be preferred.
In the absence of the three aforementioned contraindications, vaginal delivery may be considered. It is recommended to determine the position and orientation of the fetal head and spine using ultrasound, as in some cases there is a discrepancy between the orientation of the fetal head and spine, which is crucial for choosing the direction of manual rotation.
It should be taken into account that in the anthropoid pelvic shape, which is characterized by a narrow pubic arch but sufficient room in the posterior pelvic compartments, the posterior position of the fetal head presentation is a variant corresponding to the biomechanism of labor, and manual head rotation is not required. If conditions for an operative vaginal delivery are met in this situation, delivery using obstetric forceps is appropriate, taking into account the direction of tractions for the posterior position of the fetal head.
In the gynecoid pelvic shape, an attempt at manual fetal head rotation followed by the application of obstetric forceps may be performed, as it is associated with a lower failure rate compared to vacuum extraction. If manual fetal head rotation fails, delivery by Cesarean section is indicated.
Conditions for manual fetal head rotation:
- absence of contraindications for vaginal delivery,
- gynecoid pelvis shape,
- position and orientation of the head and spine confirmed by ultrasound,
- clinical adequacy of pelvic dimensions and fetal head size,
- emptied bladder of the woman in labor,
- lithotomy position of the woman in labor with flexed hips and leg support at the calf level,
- rotation performed by an experienced physician,
- informed consent of the woman in labor.
Technique of manual rotation. There are two techniques for manual fetal head rotation to achieve rotation from the posterior to the anterior position: manual (whole hand) and digital. In manual rotation, the physician inserts a hand into the vagina (right hand for position 1, left hand for position 2) and places 4 fingers under the head from the chin to the occiput, and the thumb on the opposite side (see Fig. 1A). The head is slightly pushed upward, flexed, and rotated (counterclockwise for position 1, clockwise for position 2). Rotation is best performed between contractions and if the patient remains under epidural analgesia. Caution should be exercised when pushing the head away, as excessive repulsion can lead to umbilical cord prolapse. In digital rotation, the physician uses two fingers (index and middle), placing them on the anteriorly facing posterior surface of the fetal parietal bone, with the middle finger located at the junction of the sagittal suture and the small fontanelle (Fig. 1B).
Figure 1. Manual (A) and digital (B) fetal head rotation.
(Posterior presentations of the occiput. In: American College of Obstetricians and Gynecologists. Dennen’s forceps deliveries. 4th ed. Washington, DC: American College of Obstetricians and Gynecologists; 2001. Barth. Persistent Occiput Posterior. Obstet Gynecol 2015).
Appendix C. Patient Information
If an anatomically narrow pelvis has been detected, discuss further management and examination plans with your physician.
You will likely be hospitalized in an obstetric inpatient facility in advance to prepare for delivery.
In case of fetal macrosomia and narrow pelvic dimensions, you may be offered delivery via scheduled Cesarean section.
Upon the onset of regular labor activity, delivery with a functional pelvic assessment (targeted monitoring of the correspondence between the fetal head/size and the mother's pelvis) is possible. For a successful outcome of labor, good uterine activity, pelvic dimensions sufficient for the child's descent, and correct head engagement are necessary. In the absence or slowing of labor progress, or the appearance of signs indicating fetopelvic disproportion, you will be offered delivery via emergency Cesarean section.
In some cases, you may be offered labor induction before 40 weeks of gestation to reduce the likelihood of Cesarean section and trauma caused by fetopelvic disproportion.
Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools
Appendix G1. Apgar score [90]
Type: scoring system
Purpose: assessment of the newborn's condition
Content:
Parameter / Score | 0 | 1 | 2 |
|---|---|---|---|
Heart rate | Absent | <100 bpm | ≥100 bpm |
Respiration | Absent | Bradypnea, irregular | Active, regular, loud cry |
Muscle tone | Absent, limbs limp | Decreased, some flexion of extremities | Active movement |
Reflex irritability (response to stimulation during airway suctioning) | No response | Weak response (grimace, movement) | Response in the form of movement, cough, sneezing, loud cry |
Skin coloration | Generalized pallor or generalized cyanosis | Body pink and extremities blue (acrocyanosis) | Entire body and extremities pink |
Interpretation:
A score of 4–7 points at 1 minute after birth corresponds to mild or moderate birth asphyxia (P21.1, ICD-10), and 0–3 points at 1 minute after birth corresponds to severe asphyxia (P21.0, ICD-10). Although according to ICD-10 a total score of 7 points at 1 minute after birth corresponds to mild to moderate asphyxia, it is inappropriate to assign this diagnosis, since a 7-point Apgar score at the end of the 1st minute is not clinically and/or prognostically significant. The prognostic value of the first Apgar score is generally extremely low. Adverse short- and long-term outcomes correlate with low Apgar scores at 5 and 10 minutes after birth.
Explanation: The test is typically performed at 1 and 5 minutes after birth and may be repeated later if the score remains low.