Perinatal and neonatal outcomes of triplet gestations based on placental chorionicity.

The purpose of our study was to evaluate perinatal and neonatal outcomes in triplet gestations in relation to placental chorionicity. We hypothesized that triplets containing a monochorionic pair (dichorionic triamniotic) would have increased morbidity compared with triplets without a monochorionic pair (trichorionic triamniotic). We retrospectively analyzed all triplet sets > or =20 weeks delivering at our institutions from January 1995 through April 2007. Data were collected via perinatal and neonatal databases, chart review, and placental pathology. Individuals in dichorionic triamniotic triplet sets (N = 75), when compared with trichorionic triamniotic triplets (N = 309), were more likely to have a lower mean birth weight (P < 0.001) and lower gestational age at delivery (P < 0.001), spend more days in the neonatal intensive care unit (P = 0.045), have culture-proven sepsis (P = 0.02), and require intubation (P = 0.05). Multivariate analysis demonstrated that dichorionicity is not an independent cause of morbidity, but results in earlier delivery and lower birth weight. Dichorionic triamniotic triplets are at increased risk for earlier deliveries and lower birth weight at delivery compared with trichorionic triamniotic triplets.