Neonatal outcome of late preterm uncomplicated monochorionic twins: What is the optimal time for delivery?

Objective: To determine the neonatal outcome at late prematurity of uncomplicated monochorionic (MC) twin pregnancies.Methods: A retrospective cohort study of 166 patients with uncomplicated MC diamniotic twins delivered between 34 and37 weeks of gestation at a single tertiary center. The study population was classified into four groups according to the gestational age at delivery: (1) 34 weeks, (2) 35 weeks, (3) 36 weeks and (4) 37 weeks. Neonatal outcome measures were compared between the groups.Results: Neonatal morbidity was significantly higher at 34 weeks of gestation compared to the other three groups including respiratory distress syndrome, oxygen requirement, hypothermia and hyperbilirubinemia. Moreover, the rate of admission to the special care unit and need for phototherapy were significantly higher in newborns born at 36 weeks compared to 37 weeks of gestation (p = 0.02 and 0.03 respectively). Multiple regression analysis revealed that the risk for adverse neonatal outcome was significantly associated with gestational age at delivery. Of note, there were no fetal or neonatal deaths in our cohort.Conclusions: The risk of neonatal morbidity of uncomplicated MC twins delivered at 34-37 weeks of gestation significantly decreases with advanced gestation. Therefore, under close fetal surveillance, uncomplicated MC twin pregnancies should be delivered at 37 weeks of gestation.