Chapter 46: Twin Delivery

BACKGROUND

• The incidence of multifetal gestations has increased dramatically in the United States due to:

  • Advanced maternal age when multifetal gestations are more likely to occur naturally (Odds Ratio = 4.5) compared to younger women.

  • Increased use of assisted reproductive technology.¹

• Major perinatal complications are increased with multiple gestations, including preterm birth, fetal anomalies, preeclampsia, and gestational diabetes. The risk of stillbirth begins to increase significantly at approximately 38 weeks of gestational age.

• Types of twin pregnancy include monochorionic/monoamniotic twins, monochorionic/diamniotic twins, and dichorionic/diamniotic twins.

• Based on standard obstetric nomenclature, Twin A is the presenting twin.

• The optimal route and timing of delivery in women with multifetal gestations depend on multiple factors, including the type of gestation, fetal presentations, fetal weight, gestational age, and the experience of the obstetricians.¹

• Delivery timing: uncomplicated dichorionic twins 37 to 38 weeks gestation; uncomplicated monochorionic diamnionic twins 34 to 36 weeks gestation; uncomplicated monochorionic monoamniotic twins 32 to 34 weeks gestation.

• Vaginal delivery is a reasonable option.² However, monoamniotic twins are delivered by cesarean between 32 and 34 weeks of gestation to avoid an umbilical cord complication.

• Options for delivery of the second nonvertex presenting twin include:

  • Breech extraction.

  • Internal podalic version with breech extraction.

  • Internal cephalic version.

  • Cesarean delivery.

• Possible cesarean delivery could be called during twin delivery for one or both twins.

FOR ANESTHESIOLOGISTS

• As always, ensure that you have a functional epidural.

• All twin vaginal delivery should occur in the operating room. At the commencement of the second stage of labor, the patient should be moved to an operating room.

• For a multiparous woman, she may enter the operating room earlier in anticipation of rapid delivery.

• Close the anesthesia record in the labor room and continue the same record in the operating room.

• Assist the nurse with the transfer of the patient to an operating room so that the epidural pump and medications can be safely continued.

• Continue labor epidural infusion.

• An anesthesia resident and attending should be present for the delivery of twins.

• Be prepared for emergent cesarean delivery. Chloroprocaine 3% and bicarbonate should be available to draw and dose quickly.

• Emergencies are uncommon after the delivery of Twin A, but must be prepared for emergent cesarean delivery.

  • Twin B changes lie to transverse or breech.

  • Placental abruption with fetal heart rate (FHR) abnormality or bradycardia.

  • Twin B has cord prolapse.

  • Twin B’s head engages the cervix/pelvis for the first time and experiences a prolonged FHR deceleration.

• The anesthesia team may step out once both babies are delivered and adequate uterine tone has been achieved. In some nulliparous women, it may take a significant amount of additional time to deliver Twin B, sometimes even leading to the mother returning to the labor room. If this is the intended plan, ensure that Twin B maintains a cephalic position and is stable for several contractions (>10-15 minutes).

• If magnesium sulfate is used for ...