Impact of Chorionicity on Maternal, Perinatal, and Neonatal Outcomes in Triplet Pregnancies: A 15-Year Experience From a Tertiary Care Center in Italy

Abstract Triplet pregnancies are linked to a higher risk of maternal and fetal complications compared to twins and singletons. Chorionicity has been suggested as a key factor influencing perinatal and maternal outcomes in triplet pregnancies; however, more evidence is needed to clarify its role. This study aimed to assess the impact of chorionicity on adverse maternal, fetal, and neonatal outcomes in triplet pregnancies. This retrospective observational study was conducted on triplet pregnancies delivered between 2010 and 2025 at Florence University Hospital, a tertiary referral maternity center. A total of 77 triplet pregnancies were included, 51 trichorionic and 26 nontrichorionic, resulting in the delivery of 214 newborns. Maternal characteristics and obstetric, fetal, and neonatal complications were compared based on chorionicity. Multivariate logistic regression analyses identified complications most strongly associated with chorionicity, after adjusting for maternal age, mode of conception, and gestational age at delivery. Women with nontrichorionic triplet pregnancies had higher risks of delivering earlier and postpartum hemorrhage. Their newborns had significantly lower birth weights, a greater need for neonatal intensive care admission and respiratory support, and higher rates of hypoglycemia and sepsis. The multivariate logistic regression confirmed nontrichorionicity as an independent factor associated with earlier delivery and postpartum hemorrhage. Chorionicity plays an essential role in determining the prognosis of triplet pregnancies. Nontrichorionic pregnancies are strongly linked to earlier delivery, lower birth weights, and increased neonatal complications. These findings are useful for counseling patients, helping them understand specific risks based on chorionicity, although intensive prenatal care remains critical for all triplet pregnancies.