Fetal Breech Presentation: Classification, Risk Factors and Management of Labor

The longitudinal position of the fetus can be manifested by breech presentation, in which case the breech or legs of the fetus are the first to move through the birth canal.

The prevalence of breech presentation decreases from about 20% at 28 weeks of gestation to 3-4% by 38 weeks of gestation.

The incidence of recurrent breech presentation for repeat pregnancies is nearly 10% and 27% for third pregnancies.

Classification of fetal breech presentation

There are different variations of fetal breech presentation:

• Breech. In breech presentation, the fetus bends the leg at the hip joint and the legs straighten with the feet near the face.

• Full-footed. In a full-footed presentation, the fetus assumes a sitting position with its legs bent at the hip and knee joints.

• Incomplete footbirth. In incomplete breech presentation, one of the fetal legs is bent at the hip joint with the foot near the face, while the other maintains the same position as in full breech presentation.

• Mixed. In a mixed presentation, both the buttocks and feet of the fetus are attached.

Risk factors

The most common clinical conditions or processes that lead to breech presentation tend to affect fetal mobility or the vertical axis of the uterine cavity:

• Müllerian duct anomalies: uterus with septum, bicornuate uterus, etc;
• Placentation pathology: placenta previa, as the placenta occupies the lower part of the uterine cavity;
• Uterine leiomyoma: large myomas are mainly located in the lower segment of the uterus and disrupt the fixation of the preterm fetus;
• Prematurity;
• Aneuploidies and neuromuscular disorders of the fetus usually cause hypotonia, an inability to move effectively;
• Congenital anomalies: fetal teratoma, fetal thyroid goiter, etc.;
• Polyuria;
• Low birth weight;
• Failure of the maternal anterior abdominal wall muscles.

Complications of breech presentation

The risk of umbilical cord prolapse varies according to the type of breech presentation. The incomplete and full foot presentation has the highest risk of cord prolapse, ranging from 15% to 18%, while the breech presentation is rare, with a risk of only 0.5%.

Diagnosis of fetal breech presentation

The type of breech is clinically determined after 36 weeks of gestation. Using Leopold’s techniques during the external obstetric examination combined with cervical examination, breech presentation can be diagnosed.

• The fetal head is felt as round, firm and mobile, you can feel the depression under the head and the transition to the cervical region;
• The buttocks feel bulkier, less firm and less mobile than the glans.

During the vaginal examination, there is usually no fixation of the antecubital part, the soft tissues of the buttocks or foot may be identified. During labor, vaginal examination reveals a “soft mass” separated by a cleft between the buttocks, with possible palpation of a rigid structure, the sacrum.

After the rupture of the shells:

• The anus can be palpated in the middle of the inter- gluteal crevice;
• You can also palpate the foot in a foot-shaped breech presentation.

Clinical diagnosis can be difficult: the arm can be mistaken for a leg and the face for the buttocks. Ultrasound is the most accurate method to confirm the diagnosis. The following should be documented in the ultrasound report:

• Type of breech presentation;
• The degree of extension of the fetal head;
• Estimated fetal weight;
• Amniotic fluid volume;
• Location of the placenta;
• Presence or absence of malformations.

Women with confirmed breech presentation at 36 weeks or more should be reviewed to determine the method of delivery. The discussion should take into account:

• Individual risk;
• Obstetric history;
• Gynecological diseases;
• Somatic pathology.

The differential diagnosis includes:

• Facial or frontal presentation;
• Fetal anomalies;
• Antenatal fetal death;
• Multiple pregnancies;
• Low birth weight;
• Pelvic anomalies;
• Uterine anomalies.

Tactics of labor management in breech presentation

Women should be informed of the fact that:

• Physiologic breech delivery is associated with a risk of perinatal mortality of 2 per 1000 newborns compared with cephalic presentation (1 per 1000) and planned cesarean section (0.5 per 1000);
• It was found that from 28 to 31 6/7 weeks, there was a significant decrease in perinatal morbidity and mortality with planned cesarean section compared to intended vaginal delivery. At the same time, from 32 to 36 weeks of gestation, no difference in perinatal morbidity and mortality was observed between these modes of delivery.
• After vaginal delivery, there is an increased risk of low Apgar score at 1 minute of life and short-term complications, but the risks of long-term outcomes are unchanged;
• If the mother has a successful physiologic delivery, the risk of postpartum complications is reduced compared to a planned cesarean section;
• Epidural analgesia is not contraindicated in physiologic labor, but increases the risk of obstetric interventions in labor;
• Induction and stimulation of labor are not recommended.

Indications for natural childbirth

For natural childbirth, the following criteria must be met:

• There are no other indications for a cesarean section;
• There is no evidence of antenatal fetal death;
• There is no evidence of fetal head hyperextension on ultrasound;
• The weight of the fruit does not exceed 3600 g;
• Fetal weight is not estimated to be low;
• No history of cesarean section surgery;
• A physician trained in breech delivery should be present.

Techniques for vaginal delivery

Three techniques for the management of vaginal delivery are described:

• Spontaneous labor: no manipulation or techniques are used to extract the baby. This tactic is applicable for preterm labor.
• Assisted delivery: this is the most common technique. The breech to the umbilical ring is allowed on its own, and then a technique is used to extract the shoulder blades, arms and head. An episiotomy is mandatory. No traction should be applied until the umbilical ring is visualized, and then the mother should be assisted at the same time as pushing. In case of difficulty in extracting the fetal legs, the Pinard maneuver may be necessary. Pressure is applied to the hamstring. The knee should then be bent and the fetal pedicle extracted medially.
• Full fetal extraction: Tsovianov 1-2, taking into account the types of breech presentation, as well as manual extraction. The aim of the manual assistance is to preserve the natural penis position of the fetus and to prevent prolapse of the fetal legs. It is performed from the moment the breech erupts.
  • Tsovianov 1: The breech with the fetal legs is secured with both hands of the obstetrician, simulating the continuation of the birth canal. When extracting up to the inferior angle of the scapula, the fetal body is deflected upwards. After extracting the anterior scapula, the specialist directs the buttocks toward, down, and to the side for the birth of the anterior arm. Then, by lifting the fetal body upward, the posterior knob is born. After performing an internal rotation of the head with fixation of the suboccipital fossa, the fetal body is born toward the mother’s abdomen.
  • The Tsovianov 2 technique: is used for the formation of a mixed breech from a foot breech. The perineum is closed with the obstetrician’s palm using a sterile tissue. The assistance is performed until the fetus’ buttocks are lowered to the pelvic floor at the same level as the legs. This is followed by classical manual assistance.

In the following conditions, it is customary to use the manual classic aid to facilitate the birth of the fetal head and shoulders:

• Leggy type of breech presentation;
• Mixed breech-foot presentation;
• Prolapse or reclination of the limbs, and difficulty in extricating the head.
  

An important requirement for the allowance is the delivery of the fetal body to the inferior angle of the scapulae.

The first step is the removal of the handles. The fetal legs are grasped with the opposite hand of the obstetrician, with the posterior fetal hand held at the ankles. The fetal body is tilted toward the anterior superior iliac spine of the mother, opposite the fetal back. With the second and third fingers of the same hand, the fetal pen is withdrawn with a washing motion and pressure on the ulnar crease. The other pen is manipulated in the same way.

The fetal head is withdrawn by the Morisot-Levré-Lachapelle technique. The fetal thorax is placed on the midwife’s palm. The midwife’s middle finger is inserted into the fetal mouth, and the index finger and ring finger are placed on the maxilla. The back, shoulders and occiput of the fetus are secured with the other hand, with the second finger and fourth finger placed on the shoulders and the third finger on the suboccipital fossa. Synchronously, both hands bend the head, with the fetal body directed upward. All manipulations are carried out simultaneously with pushing. Another method of withdrawal of the head according to Smelli-Fite differs in the location of the finger not in the oral cavity, but on the upper jaw.

External obstetric fetal turn

The success rate of external obstetric fetal rotation ranges from 35% to 86%. Better success rates are associated with earlier gestational age and pure breech presentation. Opinions differ regarding the influence of maternal weight, placental position, and amniotic fluid volume. The majority of practitioners believe that in repeat mothers, patients with normal weight, posterior placental positioning, and sufficient amniotic fluid volume have an increased chance of successful turning.

Risks associated with the manipulation

The most common complication is a temporary slowing of the fetal heart rate (up to 40% of cases). This condition persists for several minutes after termination of the procedure and is not associated with adverse effects on the fetus.

Among the rare complications described are:

• Fetal bone fractures;
• Premature rupture of the fetal membranes;
• Premature detachment of the normally located placenta;
• Hemorrhage and uterine rupture.

There is currently a paucity of studies that show whether the overall risk of perinatal mortality increases after external rotation. The 2015 Cochrane review identified the risk of perinatal death in patients who underwent external rotation as 2 out of 644 cases, compared to 6 out of 661 in the no manipulation group.

Methodology

The day before, an ultrasound scan is performed to determine the fetal position, weight and volume of amniotic fluid, and to rule out placenta previa and fetal anomalies. A non-stress test (alternative: fetal biophysical profile) must be performed the day before the manipulation.

The procedure is performed in a deployed operating room with the mandatory presence of anesthesiologists-anesthesiologists-anesthesiologists. Routine tocolysis and routine use of spinal or epidural anesthesia are not recommended.

Outward turning is accomplished by gently moving the head end toward the woman’s pelvis while the pelvic end moves toward the uterine fundus. There is no consensus on how many attempts at turning can be made.

After a coup attempt, regardless of its success, a non-stress test should be repeated (biophysical profile if necessary). In addition, Rh immunoglobulin should be administered to women with Rh-negative blood.

After successful manipulation, labor should not be induced immediately. The patient is discharged home and is admitted to the maternity hospital at the onset of labor or for other indications.

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Caesarean section

Scheduled cesarean section is performed at ≥ 39 weeks’ gestation in order to facilitate optimal physiologic maturation of the fetus. Except in cases where there are indications for early delivery.