Perinatal outcome of singleton versus twin late preterm infants: do twins mature faster than singletons?

Objective: To determine whether as a result of an assumed advanced maturation late preterm twin infants have a more favorable perinatal outcome than singleton late preterm infants.Methods: Over a 36-month period (from September 2011 to September 2014), 277 late preterm infants (153 from singleton and 124 from twin pregnancies) were hospitalised in NICU, University Hospital Center Sisters of Mercy Zagreb, Croatia, and were retrospectively studied by review of maternal and neonatal charts for gestational age, sex, birth weight, mode of delivery, 5-min Apgar score and for several outcome variables expected for preterm infants, until the day of discharge.Results: There was statistically no significant difference in the incidence of any of the observed and compared outcomes, except in the incidence of phototherapy which was higher in singletons group (49.01 versus 13.7%, p<0.0001). The mean birth weight, as expected, was smaller in the twin group. Conclusions: We found no evidence to support the traditional belief that twin late preterm infants have accelerated maturation and better neonatal outcome compared with singleton late preterm infants. Our findings suggest that late preterm twins have a prognosis similar to that of singleton late preterm infants born at the same gestational age.