Maternal and neonatal outcomes in pregestational and gestational diabetes mellitus, and the influence of maternal obesity and weight gain: the DEPOSIT study. Diabetes Endocrine Pregnancy Outcome Study in Toronto.

We prospectively studied pregnancy outcome in 428 women with gestational diabetes mellitus (DM) and 196 women with pregestational DM, with particular reference to the influence of maternal obesity and excessive weight gain. These were consecutive singleton pregnancies delivered in our institution over 5 years. After controlling for multiple risk factors, including maternal BMI and pregnancy weight gain, women with pregestational DM were at increased risk (compared to those with gestational DM) for Caesarean delivery (OR 3.6, 95%CI 2.3-5.6), shoulder dystocia or cephalopelvic disproportion (OR 2.2, 95%CI 1.3-3.6), and gestational hypertension or toxaemia (OR 3.0, 95%CI 1.7-5.4). The offspring of these women were also at increased risk for admission to the neonatal intensive care unit (OR 4.0, 95%CI 2.3-6.8), large-for-gestational-age birthweight (OR 3.5, 95%CI 2.2-5.6), and preterm birth before 37 weeks (OR 3.8, 95%CI 2.5-5.9). Maternal obesity, and, to a lesser degree, excessive weight gain, were also independent risk factors for all these adverse maternal and neonatal outcomes, regardless of the type of DM, except for shoulder dystocia/cephalopelvic disproportion.