Obesity and excessive weight gain during pregnancy are associated with poor outcomes for mother and baby. These include gestational diabetes, raised blood pressure (hypertension) in pregnancy, maternal venous blood clots (thromboembolism), delivery by caesarean section, high birthweight, stillbirth, maternal infection (sepsis), heavy maternal bleeding (haemorrhage) after delivery, and maternal death. As the number of women of childbearing age who are obese has increased so too has the number of women of childbearing age undergoing bariatric (weight-loss) surgery. This has resulted in an increased number of pregnant women with a history of weight-loss surgery. The most common bariatric procedure is gastric banding (laparoscopic adjustable gastric banding) in which a band containing a fluid-filled balloon is placed around the upper portion of the stomach creating a small upper pouch which limits transport of food into the lower pouch. This reduces a person's capacity to ingest food and so reduces nutritional intake. The volume of the balloon can be adjusted by addition to or removal of fluid from the balloon.

At present there is no guidance on the best management of a gastric band during pregnancy and there is variation in care. Some clinicians advocate leaving the balloon filled (inflated) to limit food intake and limit weight gain during pregnancy. This strategy might reduce the likelihood of maternal high blood pressure or gestational diabetes and so improve the outcomes for mother and baby. There are concerns, however, that leaving the balloon inflated might reduce the intake of essential nutrients needed for normal fetal development and growth. In addition, it is possible that band complications, including nausea and vomiting, slippage or migration of the band because of the increased intra-abdominal pressure with pregnancy, might occur more frequently if the balloon is left inflated. As a result, some clinicians prefer to remove fluid to deflate the balloon when the woman becomes pregnant.

This review aimed to compare outcomes for mothers and babies according to whether the balloon is deflated at the beginning of pregnancy compared to maintaining balloon inflation in pregnancy. No studies met the criteria for inclusion in the review. No conclusions can be drawn from randomised controlled trials regarding the best management of the gastric band in pregnancy. Further research is needed to define optimum management of the gastric band balloon during pregnancy.