Pre-gestational maternal body mass index predicts an increased risk of congenital malformations in infants of mothers with gestational diabetes

Aims The aim of the present study was to identify characteristics in women diagnosed with gestational diabetes mellitus (GDM) that could be predictive of congenital malformations in their infants. Methods Using data from the Spanish Collaborative Study of Congenital Malformations (ECEMC), a hospital‐based case‐control study and surveillance system, we assessed the relationship between a number of maternal variables, including pre‐gestational body mass index (BMI), and specific congenital malformations in their infants. Results The overall risk for a selected group of congenital malformations in an infant of an obese mother with GDM compared with an obese mother with normal glucose tolerance (NGT) was 2.78 (1.38–5.55, P