TUESDAY, May 8 (HealthDay News) -- Women who use an intrauterine device (IUD) as birth control may not have to worry about gaining weight after the device is implanted, new research suggests.
Researchers compared the medical records of 223 women aged 15 to 44 who were using two different types of IUDs, following them for up to two years later.
About half of the women had a non-hormonal IUD containing copper while others used a hormonal IUD that released low levels of a progestin hormone called levonorgestrel (LNG) every day.
Women in both groups appeared to lose about 1 percent of their body weight in the first and second years of having an IUD.
The study was scheduled to be presented Monday at the American College of Obstetricians and Gynecologists annual meeting in San Diego.
"We really expected to see weight gain, and we didn't even expect that there would be weight loss," said study author Dr. Erika Kwock, an obstetrician and gynecologist at Kaiser Permanente Northern California in Santa Clara.
Although previous research has not found associations between hormonal or non-hormonal IUDs and weight gain, Kwock thought that the women in her study would put on pounds "just because over time people tend to gain weight regardless of contraception," she said.
However, Kwock pointed out that the weight loss among the women in her study is probably not a reliable result. Her study did not include enough women to allow for a statistical analysis to show that the women actually shed pounds.
Still, "the numbers are encouraging that there is not a weight difference for LNG IUDs and copper IUDs," Kwock said.
Dr. Jill Rabin, head of urogynecology at Long Island Jewish Medical Center in New Hyde Park, N.Y., said, "This study is interesting because it opens the door for more questions and more research."
But there were not enough women in the study
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