Comparison of perinatal outcomes in late preterm birth between singleton and twin pregnancies

OBJECTIVE To determine whether late preterm twin neonates have a more favorable perinatal outcome than singleton late preterm neonates. METHODS We studied 401 late preterm births between 34+0 and 36+6 weeks of gestation, from January 2011 to December 2014 in our institution. We compared the maternal and neonatal characteristics and perinatal outcomes between singleton and twin pregnancies. Perinatal outcomes included Apgar score, admission to the neonatal intensive care unit (NICU) or special care nursery, duration of NICU stay, and the rate of composite morbidity (antibiotic use, hypoglycemia, hypocalcemia, hyperbilirubinemia requiring phototherapy, respiratory support, and respiratory distress syndrome). RESULTS A total of 289 neonates were in the singleton group and 112 in the twin group. The twin group showed smaller mean birth weight despite of longer gestational age at delivery. In addition, there were significant differences in the indication of delivery and cesarean section rate between the 2 groups. Overall, the risk of composite morbidity was similar between 2 groups (odds ratio, 1.4; 95% confidence interval, 0.8 to 2.4). CONCLUSION Our findings suggest that late preterm twins do not show a more favorable outcome than singleton late preterm births.