In the latest years the number of pregnant women having undergone bariatric surgery before pregnancy has increased rapidly. In pregnancy, they seem to have a reduced risk of obesity-related complications but an increased risk of mechanical complications causing small bowel obstruction and complications due to malabsorption. This article reviews the effect of bariatric surgery before pregnancy on obstetric and neonatal outcomes and provides, based on the limited available evidence, recommendations for the management of pregnancy in these women.