I am going to limit this discussion having to do with one of the more common WLSurgeries that have the potential to cause rapid weight loss and make it difficult for you to absorb vital nutrients. A common W.bizLS is gastric bypass surgery where the stomach is made smaller and reroutes the intestines. Surgeries like this one and similar ones, result in rapid weight loss, lower daily intake and increase the risk factor for nutritional deficiencies. With this in mind, it is recommended that you work closely with your physician during pregnancy and postpartum. As a result of your surgery, you will need lifelong vitamin/mineral supplementation.