Diagnosis of breech presentation

The diagnosis of breech presentation is sometimes difficult. A high position of the uterine fundus, reaching the level of the xiphoid process, is one of the signs of breech presentation. A round, dense, balloting head is determined in the fundus of the uterus. In the lower part of the uterus, above the entrance to the pelvis, an irregularly shaped soft, in places denser, large part is palpated, slightly mobile, not balloting, directly passing into the plane of the back. The fetal heartbeat is usually heard more clearly above the navel according to the position.

Determining the position and type of breech presentation is done in the same way as for cephalic presentation, i.e. along the back of the fetus.

For diagnostic purposes, it is advisable to use phono- and electrocardiography of the fetus, ultrasound examination. In unclear cases, in the presence of complicated pregnancy (polyhydramnios, obesity, abdominal muscle tension, toxicosis, etc.), especially when deciding on delivery by cesarean section, at the end of pregnancy, to clarify the presenting part and position of the fetus, it is advisable to perform abdominal X-ray, determine the weight of the fetus.

The diagnosis of breech presentation of the fetus during labor is established by vaginal examination, especially with sufficient dilation of the cervical os (at least 4-5 cm) and the absence of the fetal bladder. The nature of the breech presentation (buttock, foot) is determined by the location of the ischial tuberosities and coccyx, the position and type of the fetus are specified.

Vaginal examination should be carried out very carefully, as a rough examination can injure the genitals and anus of the fetus. Breech presentation can sometimes be mistaken for facial presentation. The differential sign is the location (palpation) of the greater trochanter on the anterior buttock, which is the first to descend into the small pelvis. The examination should not be carried out during pushing.

It is also very important to distinguish the presenting leg from the arm of the fetus. In this case, you need to focus on the thumb, which is set apart on the hand, and the presence or absence of the calcaneal tubercle. The knee differs from the elbow in its more rounded shape.

Considering that the weight of the fetus in breech presentation is of significant importance when deciding on the management of labor, the estimated weight of the fetus should be determined for all women in labor with a full-term pregnancy according to A. V. Rudakov or by hardware methods (echography, magnetic resonance, pelvimetry using computed tomography, etc.).

The management of breech babies has changed in recent years. Before 1970, most breech babies were delivered vaginally. After 1970, most breech babies were delivered abdominally.

Compared with cephalic, breech births are complicated by fetal trauma 13 times, umbilical cord prolapse 5-20 times, and intrauterine hypoxia 3-8 times more often. The incidence of prematurity is 16-33%. In mixed breech presentation, perinatal mortality is higher than in pure presentation due to the increased incidence of umbilical cord prolapse. In addition, in mixed presentation, low-weight babies are born 2 times more often than in pure breech presentation. It should be considered that for a doctor who does not have sufficient experience, operative delivery is more justified, since unskilled delivery in breech presentation can lead to an increased incidence of fetal trauma, in connection with which it is necessary to strengthen the practical training of young obstetricians and gynecologists. Perinatal mortality in vaginal births in breech presentation is 5 times higher than in cephalic presentation.

An analysis of literature data over the past 30 years shows that there are basically 4 main causes of perinatal loss of children:

• prematurity with low birth weight in 25% of all cases of breech presentation (fetal weight less than 2500 g);
• congenital deformities - up to 6% of newborn children have fetal deformities;
• prolapse of the umbilical cord loops - up to 10% in foot presentations and up to 5% in pure breech presentations during childbirth;
• Birth trauma - brachial plexus paralysis, fractures of the clavicles and long bones, soft tissue injuries, intraventricular hemorrhages associated with difficulties in fetal extraction by the pelvic end. Vaginal delivery with an extended head in the uterus is also associated with significant perinatal morbidity and mortality. Until relatively recently, obstetricians tried to reduce perinatal mortality by improving the technique of delivering a baby in breech presentation, the technique of fetal extraction by the pelvic end, performing prophylactic external version of the head both under conditions of tocolysis with alpha-adrenergic agonists and without them in full-term pregnancy, the use of X-ray pelvimetry, and scoring risk factors at the end of pregnancy.

Abdominal delivery has solved the problem of compression and prolapse of the umbilical cord and birth trauma, but has not eliminated perinatal mortality associated with severe congenital malformations or severe prematurity. Therefore, modern obstetricians have come to the general conclusion that careful selection of pregnant women with breech presentation for vaginal delivery, as well as cesarean section, poses minimal risk to both the mother and the fetus and newborn.

In the domestic literature, the features of the formation of readiness for childbirth in pregnant women with breech presentation of the fetus depending on the results of corrective gymnastics have been studied, and a comprehensive method of prenatal correction of incorrect positions and breech presentations of the fetus has been proposed. A version of a set of therapeutic exercises has been developed.

Technique of external prophylactic cephalic version of the fetus. Conditions for performing the operation:

• term not less than 35-36 weeks;
• sufficient fetal mobility;
• absence of tension in the uterus and abdominal wall;
• accurate diagnosis of the position of the fetus.

It should be remembered that the frequency of breech presentation is proportional to the gestational age. Up to 30 weeks of pregnancy, it reaches 35%, while at the end of pregnancy it is only 3%. The greatest number of rotations is performed at 34 weeks of pregnancy. If the gestational age is over 34 weeks, it is necessary to perform an ultrasound scan to determine congenital malformations of the fetus, such as anencephaly, hydrocephalus, and to determine fetal hypotrophy. External version of the fetus should be performed by an experienced obstetrician one or more times between 32 and 36 weeks of pregnancy.

Based on ultrasound data, it is necessary to determine the nature of breech presentation and the location of the placenta. After the 33rd week, the position of the fetus remains stable in 95% of cases. The frequency of successful fetal head-on rotation without tocolysis before 34 weeks of pregnancy is 75%, after 34 weeks - only 45%. The overall frequency of successful rotation is about 60%. Therefore, in modern conditions, about 75% of pregnant women with breech presentation are delivered by cesarean section.

A number of modern obstetricians use external obstetric version of the fetus on the head with tocolysis, especially at 37 weeks and above. Before the version, intravenous drip infusion of beta-adrenergic agonists is administered (for example, terbutaline at a dose of 5 mcg/min or ritodrine at a dose of 0.2 mg/min). Relaxation of the uterus is considered adequate if unimpeded palpation of parts of the fetus through the uterine wall is ensured. The most unfavorable prognostic factors are the descent of the buttocks into the pelvic cavity and posterior rotation of the fetal back.

We prefer the following method of fetal rotation to reduce the incidence of breech presentation: after the 30th week of pregnancy, twice a day on an empty stomach (morning and evening), the pregnant woman is placed in a supine position with a raised pelvis. For this purpose, a polster up to 30 cm high is placed under the sacrum and a moderate Trendelenburg is created with a slight abduction of the hips. In this position, the pregnant woman is in a state of maximum relaxation, deep and even breathing for 10-15 minutes; the pregnant woman does this exercise for 2-3 weeks at home (up to 35 weeks of pregnancy). High efficiency of the method (90%) has been established. Simplicity and the absence of complications that can be observed with prophylactic external version (with or without tocolysis) allow us to recommend it as the most effective, simple and accessible at home.

One of the frequent complications during pregnancy with breech presentation of the fetus is preterm (premature) rupture of membranes caused by the absence of the girdle of contact. Therefore, pregnant women with breech presentation of the fetus with a normal course of pregnancy and no extragenital diseases must be hospitalized in the pathology department 7-10 days before delivery. Pregnant women with a complicated obstetric history, with pelvic stenosis of I-II degree, with a large fetus, with extragenital and other pathologies, primiparous women over 30 years old must be hospitalized 2-3 weeks before delivery.

Prenatal hospitalization allows for a number of diagnostic, preventive, and therapeutic measures to be taken in case of breech presentation of the fetus. In addition, in the absence of biological readiness for childbirth in full-term pregnancy, appropriate preparation of pregnant women is carried out and a plan for the most rational management of childbirth is drawn up.

A number of authors suggest that when deciding on the method of delivery, natural or abdominal, one should be guided by a scoring assessment of the prognostic index.

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