Maternal body mass index in pre-pregnancy diabetes: impact on birthweight and mode of delivery

Pregestational diabetes confers an increased risk of macrosomia. High Body Mass Index (BMI), in its own right, is also recognised as an independent risk factor for fetal overgrowth. The extent to which high BMI may contribute to fetal growth in a population with pre-pregnancy diabetes is unclear. We sought to examine the impact of maternal BMI on birthweight centile, mode of delivery and maternal diabetes control in a population with pre-pregnancy diabetes.