A 10-years retrospective observational study in dichorionic twin pregnancies: role of fetal gender pairing on obstetric outcome

Several studies found a sex-related increased risk of adverse pregnancy and neonatal outcome. Male fetal sex was shown to be an independent risk factor for preterm birth (PTB), gestational diabetes (GD), failure of progression in labor, cesarean delivery, neonatal morbidity and mortality. Female fetal sex would increase the risk of hypertensive dis- orders of pregnancy (HDP) and the development of type 2 mellitus diabetes after a GD complicated pregnancy. Some studies tried to analyze the impact of fetal sex on pregnancy and perinatal outcome in twins, but many of them consid- ered both monochorionic (MC) and dichorionic (DC) pregnancies and results remain debatable. Available data suggest that a male co-twin increases the risk of preterm delivery, fetal growth restriction (FGR), respiratory and neuro- logic morbidity. The incidence of HDP is likely to be higher in female carrying pregnancies than in male carrying ones, and intermediate for male-female twin pregnancies. Aim of the study was to analyze the role of fetal gender pairing on obstetric outcome.