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.

A dramatic increase in twin pregnancies has been observed in the past few decades, primarily related to assisted reproductive techniques (ART) and increased average maternal age during pregnancy. Multiple pregnancies, compared to singleton pregnancies, are associated with greater perinatal morbidity and mortality. The present study evaluated the perinatal outcomes of pregnancies with discordant anomalous twins in a tertiary maternity ward in a developing country. Data were retrospectively collected from the Instituto Fernandes Figueira/FIOCRUZ, Brazil between January 2002 and December 2014. We identified 74 twin pregnancies with discordant anomalous twins. Final data analysis was based on 40 pregnancies. Congenital defects were classified according to the International Classification of Diseases: ICD-10: the digestive system was responsible in 27 (34%) cases; the central nervous system was responsible in 18 (22%) cases; the urinary tract was responsible in 14 (17%) cases; and the circulatory system was responsible in 14 (17%) cases. A total of 19 deaths occurred during the study period, and delivery before 30.4 weeks was a significant prediction of fetal death (p = .01). The presence of hydrops in the affected fetus was related to a higher number of deaths in healthy fetuses and contributed to a worse prognosis. The presence of this condition was the cause of 12 (55.6%) deaths in healthy fetuses. A 10 times higher risk of death of a normal co-twin was observed in cases of death of the anomalous twin (p = .002, OR 10.55, 95% CI: 1.9–58.52).