Objective: To assess twins’ perinatal outcomes after planned vaginal delivery according to chorionicity.
Methods: JUMODA (JUmeaux MOde D’Accouchement) was a national prospective population-based cohort study of twin deliveries performed in 176 maternity units in France from 02/2014 to 03/2015. In this planned secondary analysis, we compared perinatal outcomes of twins born at or after 32 weeks of gestation after planned vaginal delivery when the first twin was in cephalic presentation according to chorionicity. To select a population with well recognized indications of planned vaginal delivery, we applied the same exclusion criteria as in the international randomized trial, the Twin Birth Study. Finally, twin-to-twin transfusion syndromes and twin anemia-polycythemia sequences defined complicated monochorionic twin pregnancies and were excluded. The primary outcome was a composite of intrapartum mortality and neonatal morbidity and mortality. We used multivariable logistic regression models to control for potential confounders. We conducted subgroup analyses according to birth order, first or second twin, and gestational age at delivery, before or after 37 weeks of gestation.
Results: Among 3873 women at or after 32 weeks with a cephalic first twin and a planned vaginal delivery according to the Twin Birth Study criteria, 729 (18.8%) were uncomplicated monochorionic and 3144 (81.2%) dichorionic twin pregnancies. Composite intrapartum mortality and neonatal morbidity and mortality did not differ between uncomplicated monochorionic (27/1458 (1.9%)) and dichorionic (107/6288 (1.7%)) twin pregnancies (aRR 1.07, 95% CI 0.66-1.75). No significant difference between groups was shown in subgroup analyses according to birth order and gestational age at delivery.
Conclusions: In case of planned vaginal delivery at or after 32 weeks of gestation when the first twin is in cephalic presentation, uncomplicated monochorionic twin pregnancies are not associated with higher composite intrapartum mortality and neonatal morbidity and mortality than dichorionic twin pregnancies. This article is protected by copyright. All rights reserved.