Breech presentation of the fetus is the most common variant of pelvic presentation, in which the child enters the pelvis with the buttocks or buttocks and feet. There are no specific symptoms, pathology is detected when performing external obstetric and vaginal examinations, planned ultrasound. Before giving birth, attempts are made to turn the fetus head down. The method of delivery is chosen taking into account the data on the patient’s age, the recurrence of childbirth, the size of the fetus, the detected obstetric, genital and extragenital pathology. Most pregnancies are completed by Caesarean section. In natural childbirth, obstetric aids and operations are often used.
O32.1 Breech presentation of the fetus, requiring the provision of medical care to the mother
The gluteal variant of presentation, according to research results, is detected in 2.6-4.9% of pregnancy cases. In women who have given birth many times, such obstetric pathology is diagnosed twice as often as in the first birth. Since during this presentation, the buttocks or buttocks with the feet of the child first pass through the birth canal, childbirth is often accompanied by various types of complications (soft tissue damage, traumatization of the child, the threat of oxygen starvation). At the same time, the risk of perinatal mortality increases significantly, and cesarean section surgery becomes the preferred method of resolving pregnancy. The management of pregnant and parturient women with different breech presentation requires high professionalism of medical personnel.
Usually, the factors due to which the fetus does not occupy a natural head presentation remain unknown. However, specialists in the field of obstetrics and gynecology identify a number of prerequisites that increase the likelihood of breech presentation. Such obstetric pathology can provoke:
- Prematurity. It is the most common prerequisite for breech presentation (about 20%). On the one hand, this is due to the onset of labor before the fetus has had time to turn on its head. On the other hand, with a low weight and a small length of the child, which causes its increased mobility.
- Multiple pregnancy. Multiple pregnancy leads to breech presentation in more than 10% of cases. When not one, but several fetuses develop in the uterus, the space for their free movement and rotation decreases. In addition, in such situations, polyhydramnios and fetal hypotrophy are more often observed.
- Repeated childbirth. In almost 4% of cases, breech presentation is diagnosed in pregnant women with a history of multiple births. In these women, the musculature of the anterior abdominal wall is weakened, there is some inconsistency of the myometrium due to its anatomical and neurotrophic changes.
- Violation of the size or shape of the pelvis. The fourth most common cause of breech presentation (up to 1.5%). With a narrowed pelvis or its abnormal form, fetal mobility is somewhat limited. As a result, by the 36-week term, he still does not occupy the safest position for childbirth with his head down.
- Organic pathology of reproductive organs. Physiological rotation of the fetus may be hindered by defects in the structure of the uterus (bicornuate, saddle-shaped uterus), submucous nodes and other neoplasms in the lower uterine segment, a scar after gynecological surgery or operative delivery.
- Congenital fetal abnormalities. Breech presentation is more often detected in hydrocephalus, anencephaly, Down syndrome, pathology of the development of digestive organs, heart. Usually we are talking about defects accompanied by an increase in the size of the fetus or its individual parts or a change in their mobility.
- Pathology of fetal membranes and placenta. Fixation of the head at the entrance to the uterus can be prevented by the placenta. With lack of water and shortening of the umbilical cord, the mobility of the child is limited, and with polyhydramnios — on the contrary, due to increased mobility, it is difficult for him to stay in the right position.
- Discoordinated labor activity. In such births, the tone of the myometrium is ineffectively redistributed between different parts of the uterus. As a result, the head, being the densest and largest part of the fetus, pushes off from the area of the uterine pharynx, and the child turns over on the buttocks.
Breech presentation can become a manifestation of “habitual pelvic presentation”. According to the results of some observations, in 10-22% of cases, such obstetric pathology develops precisely for this reason.
Breech presentation occurs against the background of a discrepancy between the volume of the uterine cavity and the size of the fetus. Under normal conditions, up to 28-30 weeks of gestational age, the position of the fetus repeatedly changes. By about 36 weeks, the baby turns upside down and that’s how it enters labor. However, when conditions arise for increased mobility (polyhydramnios, prematurity, weakening of abdominal and uterine muscles) or, conversely, limited space for movement (multiple pregnancy, narrowed pelvis, malformations, volumetric processes, etc. P.) the natural rotation of the fetus and its fixation in the physiological position are complicated or become impossible.
When determining the variant of breech presentation, it is taken into account how the feet and buttocks of the fetus are placed in relation to the internal uterine pharynx. There are the following types of presentation:
- Clean buttock. It makes up to 63-68% of pelvic presentations. The birth canal includes the buttocks of the fetus, and its legs are stretched along the trunk. It is more typical for the first childbirth.
- Mixed gluteal. It is observed in 20-23% of cases. The child enters the pelvis with buttocks and legs bent at the knee joints. It occurs more often in re-giving birth.
After the onset of labor, one type of presentation may be replaced by another. In every third case, there is a transition of the breech presentation to the foot, which significantly worsens the prognosis of childbirth.
Symptoms of breech presentation
There is no subjective symptomatology indicating such a presentation. Usually, the pathological location of the fetus is detected during an external obstetric examination, planned or unscheduled ultrasound during pregnancy. A woman may suspect that the child is in the buttocks-down position if the bottom of the uterus is high, and a dense rounded formation (the fetal head) is felt in the upper part of the organ. Some pregnant women report that they feel more intense stirring and strong tremors of the baby in the lower abdomen.
Childbirth with a breech presentation of the fetus is dangerous for both the child and the woman in labor. In 28-32%, they occur prematurely at a gestational age of up to 34 weeks. The indicators of perinatal mortality are 4-5 times higher than with head presentation. In these births, amniotic fluid is poured out twice as often prematurely, the fetus suffers from intranatal hypoxia, the umbilical cord falls out, the weakness of the birth forces is noted, postpartum septic diseases occur. Due to the smaller size of the adjacent gluteal part, the fetus begins to be expelled when the uterine pharynx is not fully open, which increases the likelihood of injury to the cervix or spastic contraction of its muscles, complicating the further birth of the head.
In childbirth with different variants of breech presentation, the child often throws back the handles, which requires additional manipulations. Since the nascent head presses the umbilical cord to the pelvic bones, the risk of stillbirth due to asphyxia increases. The greatest danger for the child is excessive extension of the head, leading to subdural hematomas, strokes in the cerebellum and ruptures of its namet, spinal injuries in the cervical region. The majority of classical obstetric aids for breech presentation are also characterized by increased traumatism.
To confirm the breech presentation, both physical and instrumental research methods are used. With such a pathology , the most informative:
- External obstetric examination. The bottom of the uterus is high. A dense, well-balloting head is determined at the top of the uterus, and a large non-balloting buttock of irregular shape is palpated at the bottom. During auscultation, the child’s heartbeat is heard in the navel area and even slightly higher.
- Vaginal examination. Soft tissues are palpated through the open uterine pharynx. The sacrum, the gluteal cleft and the genitals of the child are probed. With a mixed type of breech presentation, there is a foot next to the buttocks, with a clean one — an inguinal fold. The position of the child is evaluated by the position of the sacrum.
- Transabdominal ultrasound. The results of ultrasound examination are especially important for choosing the optimal medical tactics and successful delivery. The method allows you to determine exactly how bent or unbent the head is, how the baby’s legs and the umbilical cord are located.
According to indications, computer and magnetic resonance pelviometry, amnioscopy are performed at the stage of prenatal preparation. For dynamic monitoring of the fetal condition, cardiotocography is additionally prescribed. Differential diagnosis is performed with other types of positions and presentations. If necessary, the patient is advised by an anesthesiologist-resuscitator and neonatologist.
Tactics for breech presentation
To correct the pathological position of the fetus at 32-37 weeks of the gestational period, special complexes of physical exercises are used. If there are no contraindications, at 37-38 weeks, an external turn on the head according to Arkhangelsk is possible, performed under ultrasound control. However, the increased risk of complications (placental abruption, uterine rupture, premature birth) limits the purpose of such manipulation. A pregnant woman is usually hospitalized in an obstetric hospital at 38-39 weeks. The choice of obstetric tactics depends on the likelihood of a complicated course of labor. The method of delivery is determined taking into account the patient’s belonging to one of three risk groups:
- Group I. High risk: the child presumably weighs over 3,600 g, the pelvis is narrowed, the age of the first-time mother in labor exceeds 30 years, signs of hypoxia and extragenital pathology affecting childbirth have been revealed. A planned caesarean section is shown.
- Group II. Medium risk: childbirth may be complicated. Constant monitoring of the birth activity and the condition of the child is necessary. When the first signs of complications are detected, an emergency caesarean section is performed.
- Group III. Low risk: the child’s weight does not exceed 3,600 g, the woman has a normal-sized pelvis, the pregnancy proceeded without complications, according to the latest ultrasound data, the child enters labor with a bent head. A standard scheme for monitoring childbirth is recommended.
When diagnosing breech presentation in primiparous women, they are guided by a number of absolute indications for planned surgical delivery. Surgical intervention is carried out at the age of 30 years, gestation, in vitro fertilization, narrowed pelvis, defects of the reproductive system, the presence of a scar on the uterus, the detection of extragenital diseases in which it is important to turn off the forced activity, significant violations of lipid metabolism, the expected weight of the fetus up to 2.0 kg and 3.6 kg. According to statistics, childbirth with an identified breech presentation is completed by caesarean section in at least 80% of cases.
In natural childbirth, it is important to ensure high-quality monitoring of their course and obstetric protection of the perineum. To reduce the load on soft tissues, it is possible to perform an episiotomy. With mixed and pure breech presentation, childbirth is often completed with a classic manual manual or a Tsovyanov manual. In the event of conditions that threaten the life of the child and the woman in labor (hypoxia, prolonged labor, etc.), forced delivery is performed with fetal extraction for the pelvic end. At the end of labor, taking into account the high probability of ruptures, it is important to perform a qualitative examination of the soft tissues of the birth canal.
Prognosis and prevention
When choosing the right management tactics and a suitable method of delivery, the prognosis of childbirth in women with diagnosed breech presentation of the fetus is favorable. Under the conditions of regular observation by an obstetrician-gynecologist, the risk for the woman in labor and the child increases only if the birth begins prematurely. Preventive measures involve early registration in a women’s clinic, timely passage of scheduled ultrasound, performing special exercises according to indications that contribute to the child’s rotation to the head end. Secondary prevention is aimed at preventing possible complications in childbirth.