Since many obese women have difficulty getting pregnant until they lose their excess weight, weight loss surgeries offer these women some hope of having a family. Obesity is associated with polycystic ovary syndrome (PCO syndrome), a condition that alters the hormonal balance and causes irregular ovulation. Menstruation is also irregular, and cysts may form on the ovaries, which become enlarged. Some women with this syndrome do not ovulate at all.

Weight loss is the best treatment for PCO syndrome, and obese women who lose their excess weight usually regain their fertility.

However, at this time, there have been no carefully controlled studies to help physicians counsel their post-surgical patients who become pregnant. This means that it isn't truly known how long one should wait after gastric bypass surgery before conceiving, and obstetricians don't really know the ramifications of a post-surgical pregnant woman who continues to lose excess weight while pregnant.

According to Dr. Mary McGowan, who helped develop the bariatric surgery program at Catholic Medical Center in Manchester, New Hampshire, clinical findings show that post-surgical women are much less likely to experience the complications associated with diabetes and high blood pressure, and they should experience fewer premature births than obese women who become pregnant before losing weight. However, more studies are needed.

To help fill in some of the gaps in the medical knowledge, the records of 846 women who became pregnant after bariatric surgeries were studied.

Dr. Richard N. Wissler was the researcher who sifted through the data. He concluded that the outcomes of pregnancy after weight loss surgery are positive, on the whole. However, he suggested that women who become pregnant after bariatric surgery should be monitored closely for nutritional deficiencies that are a common complication of the procedures, and they should stay in touch with their surgical center.

The doctor's review of the data found that cesarean sections were performed on 27% of the women whose records were included in the study. This rate of cesarean births is about the same as for women who have not had weight loss surgery.

One-third as many post-surgical women had diabetes, and high blood pressure rates were approximately half that of women who had not had gastric bypass procedures. Both these conditions can cause difficulties during pregnancy.

However, there were some reported complications that could be associated with gastric bypass. Nine women in the study had nutritional deficiencies, and one mother and her fetus died from infection caused by a small-bowel obstruction that went un-diagnosed for too long. Small-bowel obstruction is a possible complication from gastric bypass surgery.

Some of the women continued to lose weight after their pregnancy, but this did not appear to cause any problems.

Dr. Wissler and Dr. McGowan agree that all post-gastric bypass women who become pregnant should include their bariatric surgeons in their prenatal team. The symptoms of gastric bypass complications may not be easily detected by an obstetrician, and the woman's physician may also not be familiar with common nutritional deficiencies caused by the surgery. Even though the study did find some risks, the majority of women in the study had perfectly normal, successful pregnancies after bariatric surgery.