What are the effects of obesity on pregnancy?

Obesity is defined as a body mass index (BMI) of 30 or more. BMI is calculated as weight in kilograms divided by height in meters squared. Obesity is associated with reduced fertility due to decreased ovulation. In pregnancy, obesity is associated with increased risk for gestational diabetes, preeclampsia, cesarean delivery, long labor, fetal congenital anomalies like facial and cardiac anomalies, growth anomalies and stillbirths. The risk of stillbirth is 2.1-4.3 greater in obese compared with normal weight.