(PhysOrg.com) -- Currently, women who seek emergency contraception within 72 hours of intercourse can receive copper intrauterine devices. Though the devices are very effective at preventing pregnancy, they must be administered by a highly trained clinician and are not universally accepted by patients, as they have a higher risk of complications than oral applications. These factors stand as deterrents to some women obtaining emergency contraception after a 3-day period.
But a novel morning-after pill that was approved last March for use in Europe has undergone new testing for safety and efficacy in the U.S. The emergency contraception, ulipristal acetate (ellaOne), for women who have had unprotected sex, claims to have enough potency to protect them from pregnancy for up to 120 hours after intercourse. The one similar pill, levonorgestrel, is already approved in the U.S., but it is effective only up to 72 hours.
Both levonorgestrel and the new medication, ulipristal acetate, are manufactured by HRA Pharma of Paris, which supported the U.S. study.
Researchers studied 1,241 women requesting emergency contraception. The women enrolled in one of 45 Planned Parenthood clinics and received one 30 mg. dose of ulipristal acetate. Follow-up was performed by urine tests (chorionic gonadotropin) and the women’s return of menses.
Results indicate that ulipristal met the statistical requirements for efficacy with a pregnancy rate of 2.1 percent (26) of the women in the study. Additionally, it was found that ulipristal did not lose its potency over the time period administered (i.e., from 48 hours to 120 hours after intercourse), unlike levonorgestrel.
Side effects of ulipristal acetate were mostly headache, nausea, and abdominal pain, but the effects were mild to moderate and resolved spontaneously, according to the researchers.
The findings are published online by the Obstetrics & Gynecology journal.
Explore further: Emergency pill doesn't drop pregnancy rate
Ulipristal Acetate Taken 48-120 Hours After Intercourse for Emergency Contraception, Obstetrics & Gynecology, February 2010 - Volume 115 - Issue 2, Part 1 - pp 257-263; doi:10.1097/AOG.0b013e3181c8e2aa