If You Weigh More Than 165 Pounds, Read This

Of all the things you thought were bad about weighing more than you'd like, you might not have thought of this: a possible unwanted pregnancy.

Research is raising new concerns that the most popular type of emergency contraception - morning-after pills made from the hormone levonorgestrel, which prevents ovulation - are less effective in women who weigh more than 165 pounds. (To put this in context, the average weight of American women in their 20s is 162 pounds; in their 30s, 169 pounds, according to the Centers for Disease Control and Prevention.)

Writing in Women's Health magazine, Elizabeth Dawes Gay starts with some background: In 2013, the European-made Norlevo added a warning on its packaging that the morning-after pill begins to lose effectiveness among women who weigh 165 pounds and isn't effective at all for women weighing more than 175. Although Norlevo is chemically identical to Plan B in the United States, the Food and Drug Administration said the data was inconclusive and did not require a warning here.

But a new study led by Alison Edelman, a professor in the Department of Obstetrics and Gynecology at the Oregon Health and Science University, compared the effectiveness of a levonorgestrel-based contraceptive among women whose BMI was in the normal range and some who were considered obese. They found that it took a double dose of the drug to raise the obese women's hormone level to that of the women of normal weight.

So Gay asks: Could overweight women compensate by taking two pills if they need emergency contraception?

"As a clinical provider, I would love to tell you yes," Edelman tells her. "As a researcher, it's not something we can recommend yet." What they have shown thus far is that the level of the ovulation-inhibiting hormone could be raised by a double dose; more studies will be needed to show how those hormones actually affect the women's ovaries.

(This story has not been edited by NDTV staff and is auto-generated from a syndicated feed.)