Neonatal morbidities and need for intervention in twins and singletons born at 34-35 weeks of gestation

Objective: To compare indications for delivery and neonatal morbidities between twins and singletons born between 34 and 35 weeks of gestation. Study design: A prospective observational study was performed in which all infants born between January and August 2008, at Sheba Medical Center at 34 0/7-35 6/7 weeks of gestational age were included. Indications for delivery, infants' morbidities and medical interventions were documented. Twins and singletons were compared for antenatal maternal characteristics, risks of short-term neonatal complications and interventions. Results: One hundred and seventy-three mothers and 229 neonates (114 twins and 115 singletons) were included. Background maternal characteristics as well as the use of antenatal steroids and MgSO4 were similar between the groups. Only 44% of all deliveries were spontaneous, while the rest were indicated deliveries. Twins were born lighter and 31.9% of them were SGA. Nevertheless, singletons were significantly more likely to receive medical interventions such as prolonged oxygen use (> 1 day) and phototherapy. All late preterm infants (n = 5) needing surfactant administration were singletons. Overall, the risk of needing any medical intervention was significantly higher for singletons compared with twins (OR 1.8, 95% CI 1.02-3.2). Conclusions: A significant proportion of late preterm births is iatrogenic. Twins and singletons are dissimilar with regards to risks of short-term complications. Despite being born smaller and more SGA, twins are at lower risk of requiring medical intervention in the immediate neonatal period compared with singletons.