FRIDAY, Jan. 11 (HealthDay News) -- Women should wait at least one year after having weight-loss surgery before they try to get pregnant, researchers say.

The obesity rate among women of child-bearing age is expected to rise from about 24 percent in 2005 to about 28 percent in 2015, and the number of women having weight-loss surgery is increasing, the researchers noted.

In a review, published Jan. 11 in The Obstetrician & Gynaecologist, investigators looked at previous studies to assess the safety, limitations and advantages of weight-loss ("bariatric") surgery, and management of weight-loss surgery patients before, during and after pregnancy.

Obesity increases the risk of pregnancy complications, but weight-loss surgery reduces the risk in extremely obese women, the review authors said. One study found that 79 percent of women who had weight-loss surgery experienced no complications during their pregnancy.

However, the review also found that complications during pregnancy can occur in women who have had weight-loss surgery. One study found that gastric band slippage and movement can occur, resulting in severe vomiting, and that band leakage was reported in 24 percent of pregnancies.

Based on current evidence, the review authors recommend that women should not get pregnant for at least one year after weight-loss surgery. They noted that one study found that the miscarriage rate was 31 percent among women who became pregnant within 18 months after having weight-loss surgery, compared with 18 percent among those who waited longer than 18 months to become pregnant.

The authors also said that women who have weight-loss surgery should receive advice and information before they become pregnant on topics such as birth control, nutrition and weight gain, and vitamin supplements.

"An increasing number of women of child-bearing age are undergoing bariatric surgery procedures and need information and guidance regarding reproductive issues. In light of current evidence available, pregnancy after bariatric surgery is safer, with fewer complications, than pregnancy in morbidly obese women," review co-author Rahat Khan, a consultant obstetrician and gynecologist at Princess Alexandra Hospital NHS Trust in Harlow, England, said in a journal news release.

Guidance from a variety of health care specialists "is the key to a healthy pregnancy for women who have undergone bariatric surgery. However, this group of women should still be considered high risk by both obstetricians and surgeons," Khan added.

More information

The U.S. National Institute of Diabetes and Digestive and Kidney Diseases has more about weight loss surgery.