Obesity can affect fertility, making it more difficult to conceive and also increasing the risk of spontaneous abortion. Obesity during pregnancy is associated with numerous maternal and perinatal risks. The risk of problems increases with increasing degrees of obesity.

Obese women are at risk for medical complications such as cardiac disease, pulmonary disease, gestational hypertension, gestational diabetes, and obstructive sleep apnea. Regular exercise during pregnancy may help to reduce some of these risks.

The baby of an obese woman is at an increased risk of congenital abnormalities. Obese pregnant women have an increased risk of Caesarean section, and the success of vaginal birth after Caesarean section is decreased.

It is therefore best to optimize healthy weight before pregnancy and continue a healthy lifestyle throughout pregnancy.