Women with endometriosis at first pregnancy have an increased risk of adverse obstetric outcome

To evaluate pregnancy, delivery and neonatal outcome in singleton primiparous versus multiparous women with/without endometriosis.Multicentric, observational and cohort study on a group of Caucasian pregnant women (n = 2239) interviewed during their hospitalization for delivery in five Italian Gynecologic and Obstetric Units (Siena, Rome, Padua, Varese and Florence).Primiparous women with endometriosis (n = 219) showed significantly higher risk of small for gestational age fetuses (OR: 2.72, 95% CI 1.46-5.06), gestational diabetes (OR: 2.13, 95% CI 1.32-3.44), preterm premature rupture of membranes (OR: 2.93, 95% CI 1.24-6.87) and preterm birth (OR: 2.24, 95% CI 1.46-3.44), and were hospitalized for a longer period of time (p 0.0001) comparing with control group (n = 1331). Multiparous women with endometriosis (n = 97) delivered significantly more often small for gestational age fetuses (OR: 2.93, 95% CI 1.28-6.67) than control group (n = 592). Newborns of primiparous women with endometriosis needed more frequently intensive care (p = 0.05) and were hospitalized for a longer period of time (p 0.0001).Women with endometriosis at first pregnancy have an increased risk of impaired obstetric outcome, while a reduced number of complications occur in the successive gestation. Therefore, it is worthy for obstetricians to increase the surveillance in nulliparous women with endometriosis during pregnancy.