Gestational diabetes, not obesity, causes congenital anomalies

US researchers have calculated that 71% of congenital anomalies in children of obese women are attributable to maternal diabetes. They looked at weight, pregestational diabetes and major congenital anomalies in 42,000 singleton pregnancies at various time intervals between 1991 and 2004. With time, average maternal weight, BMI, the proportion of obese mothers and the prevalence …