Purpose: To compare neonatal outcomes of twins delivered <33 weeks' gestation in tertiary centers in Canada according to the mode of birth and presentation.
Materials and methods: This retrospective cohort from the Canadian Neonatal Network database studied preterm twins born from 24 + 0 to 32 + 6 weeks' gestation between 2005 and 2012. Twins were grouped by the mode of birth: both vaginal, combined vaginal/cesarean section (CS), and both CS. Additionally, twins were grouped by the mode of presentation: both vertex, vertex/breech, breech/vertex, and both breech. The primary outcome was a composite of mortality or severe neonatal morbidity (severe neurological injury [intraventricular hemorrhage grade 3/4 or periventricular leukomalacia], bronchopulmonary dysplasia, retinopathy of prematurity, and necrotizing enterocolitis).
Results: Of the 6636 twins, 1934 (29%) were delivered vaginally, 418 (6%) by combined vaginal birth/CS, and 4284 (65%) were born by CS. The composite did not differ between the groups. However, severe neurological injury was decreased (adjusted odds ratio [AOR], 0.77; 95% confidence interval [CI], 0.61-0.98) and respiratory distress syndrome (AOR, 1.34; 95%CI, 1.15-1.56) was increased when both the twins were delivered by CS.
Conclusions: Preterm twin infants born via CS experienced less severe neurological injury when compared to those delivered vaginally, but had an increase in respiratory distress syndrome.
Keywords: Infant; mode of delivery; mortality; multiple pregnancy; neurological injury; premature; respiratory distress syndrome.