Trends in maternal BMI, glycaemic control and perinatal outcome among type 1 diabetic pregnant women in 1989-2008

Our objective was to examine the trends in prepregnancy BMI and glycaemic control among Finnish type 1 diabetic patients and their relation to delivery mode and perinatal outcome. We analysed the obstetric records of 881 type 1 diabetic women with a singleton childbirth during 1989-2008. Maternal prepregnancy weight and height were obtained from the maternity cards, where they are recorded as reported by the mother. Maternal BMI increased significantly during 1989-2008 (p < 0.001). The mean HbA(1c) in the first trimester remained unchanged, but the midpregnancy and the last HbA(1c) before delivery increased (p = 0.009 and 0.005, respectively). Elective Caesarean sections (CS) decreased (p for trend < 0.001), while emergency CS increased (p for trend < 0.001). The mean umbilical artery (UA) pH decreased in vaginal deliveries (p for trend < 0.001). The frequency of UA pH < 7.15 and < 7.05 increased (p for trend < 0.001 and 0.008, respectively). The macrosomia rate remained at 32-40%. Neonatal intensive care unit (NICU) admissions increased (p for trend 0.03) and neonatal hypoglycaemia frequency decreased (p for trend 0.001). In multiple logistic regression analysis, maternal BMI was associated with macrosomia and NICU admission. The last HbA(1c) value before delivery was associated with delivery before 37 weeks' gestation, UA pH < 7.15, 1 min Apgar score < 7, macrosomia, NICU admission and neonatal hypoglycaemia. Self-reported pregestational BMI has increased and glycaemic control during the second half of pregnancy has deteriorated. Poor glycaemic control seems to be associated with the observed increases in adverse obstetric and perinatal outcomes.