The purpose of this study was to examine the modes of delivery in monochorionic and dichorionic twin pregnancies. The study was a retrospective cohort analysis of women who had diamniotic twins delivered in a single maternal–fetal care clinic in New York City between 2005 and 2021. Researchers examined the baseline features and outcomes of monochorionic and dichorionic gestations. The major result was the manner of delivery. They also examined newborn outcomes between women who attempted vaginal birth and those who did not for monochorionic–diamniotic twin pregnancies at or after 34 weeks of gestation. When applicable, data were examined using the 2 test, Fisher exact test, and t test. There were 1,121 diamniotic twin pregnancies detected, with 202 being monochorionic and 919 being dichorionic. The mode of delivery did not differ between monochorionic and dichorionic pregnancies, both in the general cohort and in the vaginal delivery subgroup. The method of birth for twin B did not differ across the groups among individuals who had a vaginal delivery of twin A. Neonatal outcomes did not differ between women who attempted vaginal delivery and those who did not try vaginal delivery in patients with monochorionic pregnancies at or after 34 weeks of gestation. When compared to dichorionic–diamniotic pregnancies, monochorionic–diamniotic pregnancies had no increased risk of caesarean delivery.
