Delivery of the nonvertex second twin: breech extraction versus external cephalic version

Our purpose was to compare the maternal and perinatal outcomes of twin gestations in which the nonvertex second twin was delivered by total breech extraction versus those delivered by external cephalic version.

The intrapartum courses of 284 consecutive twin gestations were analyzed retrospectively. Once those with actual birth weight < 600 gm, unrecognized multifetal pregnancy, multiple congenital anomalies, cesarean delivery, and/or antepartum intrauterine fetal death were excluded, 23 mothers were delivered by total breech extraction and 21 underwent external cephalic version.

The two groups were similar for mean (+/- SD) maternal age, gravidity, parity, gestational age at delivery, ultrasonographic estimate of birth weight for twin B, incidence of breech or transverse presentation for the second fetus, and actual birth weight of the first or second newborn. Suspected fetal distress that led to cesarean delivery occurred significantly more often in parturients who underwent attempted external version (4/21) than total breech extraction (0/23, p = 0.04). The incidence of eventual abdominal delivery was also significantly higher in patients who underwent attempted external cephalic version (10/21) rather than breech extraction (1/23, p = 0.001). For twin B the occurrence of low Apgar scores at 1 minute was significantly higher for infants after attempted external version (7/21) rather than breech extraction (1/23, p = 0.02), but the mean pH, number with Apgar scores < 7 at 5 minutes, and number of neonatal intensive care unit admissions were similar. No perinatal traumatic injury occurred in either group.

On the basis of our experience, total breech extraction of the nonvertex second twin is preferable to external cephalic version because it appears to be associated with a significantly lower incidence of fetal distress and abdominal delivery with comparable neonatal outcome.