Weight loss surgery may help obese women avoid pregnancy-related health complications

November 18, 2008

Obese women who have weight loss surgery before becoming pregnant have a lower risk of pregnancy-related health problems and their children are less likely to be born with complications, according to a new RAND Corporation study.

Women who underwent bariatric surgery and lost weight before becoming pregnant had a significantly lower risk of gestational diabetes and high blood pressure than obese women who did not have surgery, according to the study published in the Nov. 19 edition of the Journal of the American Medical Association.

In addition, these women's babies were less likely to be born prematurely, be born underweight or be born overweight than children born to obese women, according to the study.

"Obese women who undergo bariatric surgery and lose weight prior to becoming pregnant may improve their own health, as well as their children's health," said lead author Dr. Melinda A. Maggard, a UCLA surgeon and a researcher at RAND, a nonprofit research organization. "Further research is needed, but the results seen thus far are positive."

The incidence of bariatric surgery increased eight fold in the United States from 1998 to 2005, with women aged 18 to 45 accounting for 83 percent of the procedures. More than 150,000 women of child-bearing age underwent bariatric surgery from 2002 to 2005.

With more women of child-bearing age undergoing bariatric surgery, researchers from the Southern California Evidence-Based Practice Center wanted to assess the evidence available about medical outcomes among these women and their newborns.

The study team -- comprised primarily of researchers from RAND Health, the Greater Los Angeles VA Healthcare System and the David Geffen School of Medicine at UCLA -- conducted the study by reviewing results from 75 studies that examined health issues among women who had undergone bariatric surgery and their children.

Studies examining complication rates among women who had undergone weight loss surgery prior to becoming pregnant found that their rate of gestational diabetes and high blood pressure was nearly as low as what is seen among women who had never been obese. The impact of mothers' bariatric surgery on health complications among their newborns was even larger.

Researchers found evidence that fertility rates improved among women who had undergone bariatric surgery, but the evidence was limited in scope. Other research has shown that fertility improves among obese women who lose weight with nonsurgical methods.

Although rare, complications from bariatric surgery can occur during pregnancy, according to the report. The most-common complication is an internal hernia that causes intestinal problems. Most surgeons recommend that women delay pregnancy until a year after bariatric surgery -- the period when the most rapid weight loss occurs.

Source: RAND Corporation