New Emergency Contraceptive Prevents Pregnancy Up To Five Days, Study Finds

A study published Friday in the British medical journal Lancet found that a new type of emergency contraception, ulipristal acetate, appears to be more effective for a longer time than the most widely used form of EC, levonorgestrel, the AP/USA Today reports. The new EC pill -- available by prescription in Europe under the brand name ellaOne -- prevented pregnancy for up to five days in the study. Levonorgestrel -- sold as Levonelle and Plan B in the U.S. and more than 140 other countries -- can be taken for up to three days.

Lead author Anna Glasier of the Family Planning and Well Woman Services at Dean Terrace Centre in Edinburgh, Scotland, and colleagues followed about 1,700 women ages 16 through 36 who received either ellaOne or Plan B within three to five days of having unprotected sex. The study found that there were 22 pregnancies in the group that received levonorgestrel, compared with 15 in the group that received the newer drug. Overall, women who took ulipristal acetate had a 1.8% chance of becoming pregnant, compared with a 2.6% chance among the women who took levonorgestrel. The newer pill appeared to work consistently for up to five days, whereas levonorgestrel decreases in effectiveness over time.

Glasier said that the different ingredients in the two pills might be one reason for the discrepancy. Plan B contains synthetic progesterone and mimics the effects of the natural hormone by interfering with the ovulation as the egg develops, whereas the newer EC pill delays ovulation, according to the AP/USA Today.

Glasier said that more safety data are needed before the new drug can be recommended for over-the-counter use. She estimated that ellaOne costs about three times more than Plan B. The study was designed and funded by HRA Pharma, which produced ellaOne.

Health officials said women should still act quickly to prevent an unintended pregnancy. "The message has to be always that women should act as soon as possible," Tony Kerridge, a spokesperson for Marie Stopes International, said. He added, "You may think you have a window of opportunity, but as soon as you can, go somewhere and get it sorted [out]" (AP/USA Today, 1/28).


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