Birth control shots tied to long-term weight gain

Women who gain weight rapidly after starting birth control injections appear to be more prone to long-term weight gain, researchers have found.

Women whose weight increased by 5 percent or more within the first six months of taking the injected contraceptive Depo Provera gained an average of 24 pounds over a three-year period, researchers from the University of Texas Medical Branch at Galveston found.

These so-called "early gainers" represented about 25 percent of women who took Depo Provera. The rest experienced little to no weight gain.

Early gainers were more likely to be women who had a body mass index under 30, already had children and those who reported an increase in appetite after being on the shot for six months.

The study appears in the August issue of Obstetrics and Gynecology.

Photo: Some women on Depo Provera pay a hefty penalty, a study found. ;