Umbilical Arterial Blood Gas and Perinatal Outcome in the Second Twin according to the Planned Mode of Delivery

PURPOSE To compare umbilical arterial gas parameters in the second twin of twin pregnancies according to the mode of delivery. METHODS We retrospectively analyzed the medical records of twin deliveries after 34 weeks of gestation for 3 years. Excluding the cases which underwent emergency cesarean delivery during trial of labor, a total of 79 twin gestations had umbilical arterial blood gas values available and were and divided into cesarean delivery group (N=40) and vaginal delivery group (N=39). The mean differences of umbilical arterial blood parameters and the Apgar score between the first and second twin in each pregnancy were compared according the mode of delivery. RESULTS The differences of umbilical arterial gas parameters between twin siblings showed no significant difference according to the mode of delivery. With regard to the 1 minute and 5 minute Apgar scores, the differences between twin siblings are significantly increased in vaginal delivery group compared to cesarean delivery group (p=0.048, and p=0.038, respectively). In comparing the 28 cases delivered vaginally with an inter-twin delivery interval < 10 minutes and 40 cases delivered by cesarean section, no significant differences were observed in the umbilical arterial gas parameters and Apgar scores. CONCLUSION The inter-twin umbilical arterial blood gas parameters according to the mode of delivery showed no difference. For twin deliveries, it is relatively safe to plan for a vaginal delivery, but an effort should be made to reduce the inter-twin delivery interval time.