Breech Extraction Delivery

Fetal malpresentation occurs in about 4% of all term pregnancies. The most common malpresentation by far is breech presentation, where the fetal longitudinal lie is oriented parallel to the long axis of the uterus and the buttocks are near the cervix. There are 3 types of breech presentation: frank (hips are flexed and the legs are extended), complete (hips and legs are flexed), and footling or incomplete (incomplete flexion of one or both hips).

A transverse lie occurs when the fetal longitudinal axis is perpendicular to the long axis of the uterus. The location of the spine determines if the fetus is "back up" (the curvature of the spine is in the upper part of the uterus) or "back down" (the curvature of the spine is in the lower part of the uterus).

Abnormal fetal presentations are more common in twin gestations. Approximately 30% of all twins are in a vertex/breech presentation and 10% are vertex/transverse lie at the time of delivery.

Singleton fetuses with abnormal presentation are generally delivered at term. The safest route of delivery in such a clinical setting remains somewhat controversial. Some studies have shown that a planned cesarean delivery decreases the risk of perinatal or neonatal mortality compared to planned vaginal birth for the term singleton fetus in breech presentation.[1] The ideal time for the delivery of an uncomplicated twin gestation is also unclear. Some studies suggest that the lowest incidence of adverse perinatal outcomes is somewhere between 36-37 weeks, with a rise in perinatal mortality by 38 weeks' gestation.[2, 3, 4]

The American Congress of Obstetricians and Gynecologists (ACOG) recognizes that uncomplicated twin gestations at 38 weeks with appropriate fetal growth and reassuring fetal surveillance can be continued. However, in the event of pregnancy-associated conditions that might improve with delivery, obstetricians can consider elective delivery with documented fetal pulmonary maturity. This should be determined for each twin when technically feasible. ACOG also recommends that the mode of delivery be based on the presentation of the fetuses, the ease of fetal heart rate monitoring, and the maternal and fetal status.[5]

While the safety of a vaginal delivery for vertex/vertex twins is well documented, the ideal management when the second twin is nonvertex is still controversial.[6, 7] Despite differences in opinions on the most appropriate route of delivery for vertex/nonvertex twins, some experts agree that, in well-selected cases, vaginal breech delivery may be appropriate for the nonvertex second twin.

In the hands of an experienced obstetrician, external cephalic version and total breech extraction are 2 reasonable options for the delivery of the noncephalic second twin.[2, 6, 8, 9] Although both options are reasonable, total breech extraction is recommended because it is associated with a higher success rate of a vaginal delivery when compared to the external version of a second twin. A review by Aviram et al also concluded that breech extraction performed by an experienced obstetrician offered a greater likelihood of successful vaginal delivery of the second twin than did external cephalic version.[10]

A breech extraction refers to the procedure in which the infant's feet are grasped by the operator and the fetus is extracted from the uterine cavity through the vagina. It is performed for the delivery of the second twin in a vertex/nonvertex presentation. Successful completion of this delivery depends upon a well-trained and experienced obstetrician.[2, 7, 11] This article reviews the steps for a complete breech extraction and the possible complications that might be encountered during the procedure.

A study by Jonsdottir et al indicated that in twin births, internal podalic version and breech extraction of the second, nonvertex twin after vaginal delivery of the first twin may have a slightly better outcome than will cesarean delivery of the second twin. The study, which involved 457 twin births, included 418 cases in which the second twin was delivered by cesarean section and 39 cases in which the twin was delivered by internal podalic version and breech extraction. The investigators found a lower rate of asphyxia in the breech extractions than in the cesarean births. In addition, Apgar scores and umbilical cord pH levels tended to be higher in the infants who underwent breech extraction than in the cesarean section group, although the differences were not significant.[12]

In the absence of an operator experienced in vaginal breech delivery, cesarean delivery is prudent.

Proper patient counseling should be provided and documented in the medical record.

A breech extraction is performed for the delivery of the second twin in a nonvertex presentation once the first twin has been delivered. It is not recommended for the vaginal breech delivery of a singleton.

Contraindications include the following:

• Singleton nonvertex presentation

• Obstetrical indications for a cesarean delivery (eg, placenta previa)

• Nonreassuring fetal heart tracing

• Prolapsed umbilical cord

• Uterine anomalies

• Extreme prematurity

• Estimated weight < 1,500 g

• Twins with growth discordance when the second twin is larger than the first twin — Second twin estimated to be 25% larger than the first one, calculated by: (EFW largest fetus - EFW smallest fetus)/(EFW for the largest fetus) x 100

• Inability to perform a safe emergency cesarean delivery if breech extraction is unsuccessful

The patient must have effective analgesia, preferably epidural.

Ideally, this procedure should be performed in the operating room, in case an emergency cesarean delivery is needed. Experienced staff should be available, including an anesthesiologist and pediatrician.

Position the mother supine for vaginal delivery.

Steps in the technique are as follows:

• Obtain informed consent.

• After the delivery of the presenting twin, promptly assess the heart rate of the second twin with Doptone, ultrasound, or electronic monitor.

• The delivery of the second twin should not be delayed because the cervix may "clamp down" around the presenting part.

• If the fetal heart tracing is nonreassuring and an expedited delivery is needed, proceed with the breech extraction immediately.

• Under ultrasonographic guidance, evaluate the second twin’s presentation and locate the twin’s feet.

• To facilitate intrauterine manipulation, some providers administer a uterine relaxing agent, such as intravenous, spray, or sublingual nitroglycerin (50-200 mcg); intravenous magnesium sulfate (2 g); subcutaneous terbutaline (0.25 mg); or intravenous terbutaline (2.5-10 mcg/min). Alternatively, the anesthesiologist could administer an inhalational halogenated gas. There may not be enough time for the medication to take effect if an urgent delivery is needed.

• Introduce one hand into the uterus and grasp the feet through the intact membranes (see image below).

  Introduce one hand into the uterus and grasp the feet through intact membranes.

• Palpation of the malleolus at a perpendicular angle with the distal tibia and fibula confirms that the lower extremities are being grasped. Gentle continuous axis traction toward the birth canal should then be applied.

• The other hand should be used to guide the fetal head upward (see image below).

  With the other hand, guide the fetal head upward.

• Gently perform continuous axis traction toward the birth canal (see image below).

  Apply continuous axis traction toward the birth canal.

• Encourage the mother to push.

• Once the presenting part is engaged, rupture the membranes (see image below).

  Rupture the membranes and continue gentle traction until the hips emerge.

• Following the delivery of the legs, place a moist towel around them for a better grasp (see image below). Continue downward traction until the hips emerge.

  Place a moist towel around the legs for a better grasp.

• When the fetal hips have been delivered, place your thumbs over the sacrum and your fingers over the anterior iliac crests. Apply traction with slight rotation until the scapulae are visible (see image below).

  Continue downward traction until the delivery of the scapulae. Then rotate the fetus for the delivery of the arm.

• Rotate the fetus 90° and deliver the anterior arm by placing 1-2 fingers parallel to the humerus until they reach the elbow. Sweep the arm by gently applying pressure downward (see image below).

  Deliver the arm by placing the finger parallel to the humerus and applying downward pressure at the elbow.

• Rotate the fetus in the opposite direction and sweep the other arm.

• Once the second arm has been delivered, rotate the fetus 90° so that the spine is located anteriorly.

• Deliver the fetal head by using the Mauriceau-Smellie-Veit maneuver (see image below) or by applying Piper forceps (depending on the operator’s experience).

  Mauriceau-Smellie-Veit maneuver for the delivery of the fetal head.

• Avoid hyperextension of the cervical spine.

Complications are as follows:

• Fetal head entrapment: This may occur if the cervix is not completely dilated or the second twin is significantly larger than the first one. It may also occur if the uterus fails to relax sufficiently with the pharmacologic measures outlined above. This complication is more common with premature fetuses.

  • In this event, cervical incisions (Dührssen incisions) may be needed to release the entrapment.

  • The operator must be ready to deal with extensions into the lower uterine segment and broad ligament, significant bleeding, and failure of this technique to allow the delivery of the fetal head.

  • One to three incisions can be performed by placing the fingers inside the cervix and cutting the full length of the cervical lip at the 2-, 10-, and 6-o’clock positions. To avoid injury to the uterine vessels, do not cut the cervix at the 3-, 4-, 8-, or 9-o’clock positions.

  • Symphysiotomy has also been described. This should only be performed by experienced obstetricians. Even in skilled hands, it may be associated with an unacceptably high risk of injury to the maternal urinary tract.

• Umbilical cord prolapse: This complication does not always result in nonreassuring fetal heart tracings, but delivery must be expedited once the prolapsed cord has been recognized. If rapid extraction is not possible, proceed with cesarean delivery.

• Cervical spine injury: This complication may occur if the fetal head is hyperextended during the delivery. It may be associated with long-term neurologic sequelae.

• Abruptio placentae prior to the delivery of the second twin: In the event of an abruptio placenta, severe maternal hemorrhage and a nonreassuring fetal heart tracing may be encountered. A breech extraction should be performed only if it will be faster than the cesarean. Otherwise, the fetus should immediately be delivered by an emergency cesarean.

• Maternal trauma: Vaginal and perineal lacerations may occur during a breech extraction. Repair should be performed by a provider who is familiar with the appropriate techniques.

• Immediate postpartum hemorrhage: Twin gestations are at increased risk for postpartum hemorrhage. The most common cause is uterine atony that results from the overdistended uterus. This complication can become a catastrophic event; therefore, it should be managed promptly and systematically with medical treatment, followed by surgical intervention, as needed.

Clinicians must think ahead of time about potential complications and keep in mind the interventions required in the event of any of the above problems.