Cesarean section: general provisions and surgical access
A surgical intervention (caesarean section) in which the uterine wall is incised to extract the fetus. Access can be abdominal (laparotomy) — most commonly used for a viable fetus, and vaginal — extremely rarely in early gestations. A mini-cesarean section is performed to terminate pregnancy at 17–22 weeks for medical indications.
Indications for cesarean section
Indications are divided into elective and emergency categories:
- Elective: placenta previa, uterine scar incompetence, multiple uterine myomas, grade II anatomically contracted pelvis, breech presentation with a large fetal mass, pronounced cicatricial changes of the birth canal, extragenital cancer, high myopia.
- Emergency: placental abruption (premature separation of normally implanted placenta), impending uterine rupture, acute fetal hypoxia, eclampsia, umbilical cord prolapse, clinically contracted pelvis during labor.
Fetal versions and labor acceleration
Various techniques are used in obstetrics to change fetal position and stimulate labor:
- External cephalic version: converting the fetus to a cephalic presentation by external manual manipulation.
- Classic combined podalic version: a combination of internal and external maneuvers with a mobile fetus and fully dilated cervix.
- Amniotomy: artificial rupture of the fetal membranes using a plastic hook or finger in polyhydramnios or for labor induction.
- Bullet forceps: applied to a skin fold of the dead fetus's head with a small weight suspended to accelerate labor.
Briefly: answers to topical questions
What mandatory conditions are necessary for the application of obstetric forceps?
Mandatory conditions for the procedure are complete cervical dilatation and location of the fetal head in the narrow cavity of the pelvis. Required conditions include:
- Live fetus.
- Full cervical dilatation.
- Ruptured amniotic sac.
- Location of the head in the narrow part of the pelvic cavity (sagittal suture in the direct or nearly direct diameter).
- An empty urinary bladder.
What are the indications for obstetric forceps delivery from the mother and the fetus?
The indication is the need for emergency delivery in case of deterioration of the mother's or fetus's condition, if the fetal head is in the narrow part of the pelvic cavity. In such a situation, application of obstetric forceps is possible.
What are the absolute contraindications to the use of obstetric forceps?
Contraindications for the procedure include conditions where fetal extraction is impossible or extremely dangerous. The following contraindications are distinguished:
- Dead fetus.
- Incomplete cervical dilatation.
- Hydrocephalus, anencephaly in the fetus.
- Premature fetus.
- High station of the fetal head (at the pelvic inlet or in the wide part).
- Threatening or incipient uterine rupture.
What anatomical parts do the Simpson-Phenomenov obstetric forceps consist of?
Simpson-Phenomenov forceps consist of two blades — left and right. Each blade includes three main parts:
- Blade (spoon).
- Lock.
- Handle.
The Busch hook is located on the outer surface of the handle near the lock and serves as a support for the obstetrician's fingers.
What do the "three triple rules" entail when applying obstetric forceps?
When performing the procedure, three main rules must be strictly observed. They include:
- First rule (order of insertion) — the left blade is inserted with the left hand into the left half of the mother's pelvis, then the right blade is inserted with the right hand into the right side of the pelvis.
- Second rule (blade positioning) — the tips of the blades are directed toward the pelvic axis, the instrument grasps the head biparietally and along the large oblique diameter.
- Third rule (direction of traction) — the direction of traction must correspond to the pelvic axis (the direction of the birth canal).
How do outlet obstetric forceps differ from cavity forceps?
The main difference lies in the station of the fetal head in the lesser pelvis at the time of the procedure.
| Characteristic | Outlet forceps | Cavity typical forceps |
|---|---|---|
| Head location | Large segment at the pelvic outlet | Large segment in the narrow part of the pelvic cavity |
| Sagittal suture | In the direct diameter | In the direct or nearly direct diameter |
| Head condition | Crowning in the vaginal introitus | Located in the pelvic cavity |
What main moments (steps) does the obstetric forceps operation include?
The operation consists of four consecutive stages ensuring safe fetal extraction. The following main steps are distinguished:
- First moment — insertion of the left and then the right blade of the obstetric forceps into the mother's pelvic cavity.
- Second moment — locking of the forceps (fixation on the lateral Busch hooks) and performing test traction to check the correctness of application.
- Third moment — extraction of the fetal head (traction), which is performed synchronously with natural expulsive efforts.
- Fourth moment — removal of the forceps, which is performed after the head is delivered (first the right blade is removed, then the left).
What injuries and complications for the mother can occur when applying obstetrical forceps?
The use of the instrument is associated with the risk of severe trauma to the soft tissues and bone structures of the birth canal. Possible maternal complications include:
- Injuries and lacerations of the soft birth canal (vulva, vagina, and perineum).
- Rupture of the pubic symphysis (historically associated with the application of high forceps).
- Failed application attempt or instrument slippage, requiring an emergency conversion to cesarean delivery.
What fetal complications are associated with the use of obstetrical forceps?
Main fetal complications when applying obstetrical forceps:
- Facial nerve palsy.
- Cephalhematoma; the risk is higher when applying forceps to the fetal head located in the wide part of the pelvic cavity.
- Fetal head injuries.
- Birth of a child in a state of asphyxia, most often caused by pre-existing severe intrauterine hypoxia.
Elective CS: placenta previa, uterine scar, myoma/fetal weight (P-P-M).
Class and exam questions
What are the absolute indications for an elective cesarean section?
These include placenta previa, uterine scar insolvency, anatomically contracted pelvis of grade II severity and higher, as well as certain somatic and oncologic diseases of the mother.
What is the essence of amniotomy?
This is an artificial rupture of the fetal membranes, performed during pregnancy or labor for labor induction, labor augmentation, or in cases of polyhydramnios under medical supervision.
What are the main complications that can occur after a cesarean section?
In the postoperative period, bleeding, infectious complications, peritonitis, and thromboembolism are possible, and in subsequent pregnancies, there is a risk of uterine rupture along the scar.
What else to study on this topic
- Technique of the classical combined internal podalic version by stages
- Braxton Hicks combined version
- Wilt-Ivanov-Gauss skin-traction forceps
- Historical overview of the development of cesarean section
- Epidemiological factors behind the rising global rate of cesarean sections
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