Risk factors for combined vaginal–cesarean delivery in the vertex–vertex twins: a case–control study

In vertex-vertex twin pregnancies, successful vaginal delivery is achieved in approximately 95% of cases. Gestational diabetes mellitus independently increases the likelihood of cesarean delivery for the second twin, suggesting a possible metabolic influence on labor dynamics. Optimal glycemic control and vigilant intrapartum management may help minimize cesarean conversions. Larger multicenter studies are warranted to validate these findings and explore the effect of diabetes severity and treatment type.