Fetal-pelvic spatial relationship

Diagnosis of the onset of labor and patient routing

The main task of the obstetrician at the initial stage is to timely and accurately diagnose the onset of the labor process. Errors in determining the timing inevitably lead to incorrect management tactics. True labor activity is characterized by three key criteria: contractions become regular, the interval between them decreases to 15–20 minutes, and the process of cervical dilation begins.

Upon admission to the admission department, the sanitary and anti-epidemic regime is strictly observed. Medical staff perform hygienic treatment, measure temperature, examine the skin, and identify potential extragenital pathology. The most important step is reviewing medical documentation, primarily the exchange card.

Depending on the infectious status, routing is carried out as follows:

• Patients with contagious infections (influenza, syphilis, tuberculosis, HIV infection) are referred to the observation unit or a specialized hospital.
• Women without infectious diseases are transferred to the physiological maternity ward.

Home birth is not legalized in the Russian Federation. It can only be performed in exceptional cases: with the complete absence of pregnancy complications, extragenital pathologies, and a guarantee of emergency transportation to a hospital.

Management of the first stage and the influence of fetal position

During the stage of cervical dilation, the woman's mobility regimen depends on the method of pain relief. If epidural anesthesia is not used and not planned, the laboring woman can walk or lie down freely. Light food (chocolate, tea) is permitted, but this issue is always decided individually.

Special attention is paid to the recumbent position, which directly depends on the mutual arrangement of the fetus and the maternal pelvis. Lying on the back is strictly discouraged, as it provokes inferior vena cava compression syndrome.

Rules for choosing a posture:

• In the first fetal position, the woman should lie on her left side.
• In the second fetal position, it is necessary to turn onto the right side.

Strict control of pelvic functions is extremely important. The laboring woman must urinate every 2–3 hours. Overdistension of the bladder pathogenetically contributes to the development of uterine inertia. If spontaneous urination is impossible, the midwife performs catheterization.

Completion of the expulsion stage

The placement of the woman in the second stage depends on the structure of the department. In boxed wards, the patient stays in the same room for the entire labor (the presence of a partner is allowed). In traditional departments, the laboring woman is transferred from the pre-labor ward to the delivery room onto a special bed (in the Russian Federation, women give birth predominantly lying down, although vertical births are also possible when the patient stands).

The expulsion process itself is completed sequentially: following the birth of the shoulder girdle, the torso and legs of the fetus emerge from the birth canal. This moment is accompanied by the discharge of posterior amniotic fluid. Immediately after birth, the fetus officially acquires the status of a newborn: it takes its first independent breath and lets out a cry.

Course of the third stage of labor

The third stage of labor starts immediately after the birth of the child. At this time, the woman experiences physical and emotional relief; her pulse and respiratory rate normalize. A brief chill often occurs—this is a physiological reaction to the accumulation in tissues of under-oxidized metabolic products formed during intensive pushing efforts.

Immediately after the expulsion of the fetus, the uterine fundus is at the level of the navel, and weak placental contractions begin. The process of placental separation is accompanied by characteristic changes:

1. The placenta, along with the retroplacental hematoma, descends into the lower uterine segment.
2. The uterine body noticeably deviates to the right.
3. The organ takes on an hourglass shape: a shallow constriction forms just above the pubic symphysis.
4. The lower segment is felt upon palpation as a softish formation.

The descended afterbirth begins to press against the sacral nerve plexuses. This reflexively triggers placental bearing efforts, and after one of them, the afterbirth is delivered. Along with it, 200 to 500 ml of blood is released, which is within the physiological norm.

Options for placental separation and uterine condition

In obstetrics, two classic options for placental separation are distinguished:

• Schultze method: the placenta separates from the central areas. This option is more favorable as it is accompanied by less blood loss.
• Duncan method: separation begins from the edges. Blood loss in this case is higher, and bloody discharge may appear some time after the birth of the child, coinciding with the moment the detachment begins.

The dynamics of the height of the uterine fundus standing in the third stage are strictly regular. Immediately after the birth of the baby, the fundus is palpated at the navel level. When the afterbirth separates, the uterus rises above the navel and shifts to the right. After the final birth of the afterbirth, the uterus returns to the midline position, enters a state of maximum contraction (tone is sharply increased), and the uterine fundus height is established at 10–12 cm above the pubis.

Class and exam questions

What else to study on this topic

• Mechanisms of placental separation (Schultze and Duncan)
• Signs of afterbirth separation and the physiology of placental bearing efforts
• Routing of laboring women with contagious infections
• Vertical birth: organization and management of the second stage
• Prevention of uterine inertia in the first stage

Other topics in the "Obstetrics" section

Prepared by WhiteCoat Pro faculty in accordance with the medical school curriculum. For educational purposes only.