A. Labor and Delivery

Admit the patient to the hospital at the first sign of labor, if there is leakage of amniotic fluid, or if significant bleeding occurs. An ultrasound evaluation should be performed to ascertain the presentation of each fetus and its estimated fetal weight. Routine, continuous electronic fetal heart rate monitoring is recommended. Labor should be conducted so that immediate cesarean section can be performed if required. A pediatric nurse team for each infant plus obstetric and anesthesiologic attendants should be present. Insert an intravenous line and send a specimen of blood for typing, antibody screening, and complete blood count.

If either twin shows signs of persistent compromise, proceed promptly to cesarean section delivery. Other indications for primary cesarean section include (but are not limited to) compound or monoamniotic twins and probable twin-twin transfusion syndrome (gross disparity in fetal size) and placenta previa. Nearly all (> 85%) triplets warrant cesarean section delivery.

In a woman with a previous lower-segment cesarean scar, limited literature suggests that delivery of twins does not mandate a repeat cesarean section in the absence of other complications. Management of twins that are candidates for vaginal delivery may proceed as outlined below. Intrapartum twin presentations may be classified as follows: (1) twin A and twin B vertex (slightly > 40% of all twins); (2) twin A vertex and twin B nonvertex (almost 40%); (3) twin A nonvertex and twin B vertex, breech, or transverse (about 20%).

The current intrapartum management of twins is summarized in

Fig 17-4. For vertex-vertex presentations in labor (category 1 above), vaginal delivery of both twins may be chosen in the absence of standard indications for cesarean section delivery. Of course, if either twin develops fetal distress, cesarean section delivery should be performed.

Category 2 twins, each weighing more than 2000 g, can usually be managed successfully by vaginal delivery of both. This is generally accomplished by external version of twin B immediately after the delivery of twin A. Recent literature suggests that total breech extraction may be preferable to external cephalic version of twin B. If twin B weighs less than 2000 g and external version is unsuccessful, cesarean section for this infant is warranted (as opposed to breech vaginal birth). When either twin A or both twins are nonvertex (category 3), primary cesarean section should be performed.

Difficult forceps operation or rapid extraction should be avoided, but forceps to protect the aftercoming premature head may be useful. The umbilical cord should be clamped promptly to prevent the second twin of a monozygotic twin pregnancy from exsanguinating into the first born.

Perform a vaginal examination immediately after delivery of twin A to note the presentation of the second twin, the presence of a second sac, an occult cord prolapse, or cord entanglement.

Cut the cord as far outside the vagina as possible so that it can hang loose to permit vaginal examination or manipulation. This eliminates inadvertent cord traction on the placenta. Tag and label the cords (twin A and B) so that they may be associated with the proper placenta or placentas.

Use external version whenever possible for conversion of twin B from breech to vertex. Cautious rupture of the second sac will allow slow loss of fluid while twin B’s vertex is being gently guided into the inlet. The amount of time between delivery of twin A and B is still a matter of controversy. If estimated fetal weight suggests fetal well being, it is not necessary to deliver twin B within 30 minutes.

One twin may obstruct the delivery of both fetuses in locked twins. In this circumstance twin A is always a breech and twin B a vertex presentation. The heads become impacted in the pelvis. Locked twins can be avoided by cesarean delivery in all cases in which twin A is not vertex. However, if the obstetrician is presented with a case of locked twins (

Fig 17-5), having an assistant support the twin already partially delivered as a breech while pushing both heads upward out of the pelvis with rotation of both fetuses may accomplish delivery of the first. This may require deep anesthesia. If this cannot be done, cesarean with abdominal delivery of both fetuses may be the safest route. An alternative while cesarean preparations are underway is to elevate the partially delivered twin, establish an airway, and protect the cord.

Postpartum hemorrhage is common in multiple pregnancy. Increased intravenous oxytocin, elevation, and light massage of the fundus and an intravenous ergot or prostaglandin product (only after the last fetus is delivered) may be required.

After delivery, if separation of the placenta is delayed or bleeding is brisk, manual extraction of the placenta may be necessary. Send the placenta, cord, and membranes to the pathology laboratory to assist in determining whether the fetuses are mono- or dizygotic.

Preeclampsia-eclampsia, premature labor and delivery, etc, are managed as outlined elsewhere in this book.

Figure 17-4. Management of twin gestation, intrapartum protocol. EFW, estimated fetal weight. (Modified and reproduced, with permission of the American College of Obstetricians and Gynecologists, from Chervenak FA et al: Intrapartum management of twin gestation. Obstet Gynecol 1985;65:120.)

Figure 17-5. Locked twins. (Reproduced, with permission, from Benson RC: Handbook of Obstetrics & Gynecology, 4th ed. Lange, 1971.)