Study: The ‘Morning-After’ Pill Works the Day Before Too

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The morning-after pill is approved for use as an emergency contraceptive, meant to be taken the day after unprotected sex, but a new study suggests women might be able to use it as regular birth control as well.

The new report, a review of 15 previous studies involving 8,400 women, found that the morning-after pill was effective at pregnancy prevention, compared with condoms and spermicide: women who took the morning-after pill right around the time they had sex had about a 5% chance of pregnancy over the course of a year, compared with a 16% chance for women whose partners used condoms. (More on An Argument for Making Birth-Control Pills Available Over the Counter)

The main ingredient in the FDA-approved morning-after pill, which is available over the counter to anyone over age 17, is levonorgestrel, a synthetic form of estrogen that prevents ovulation. It’s the same hormone used in some regular birth-control pills in much lower doses. The high level of levonorgestrel in morning-after pills like Plan B and Next Choice may not make them ideal for regular use, but most of the women in the studies took only half the dose typically contained in these pills.

While the pregnancy prevention rates compared favorably to condom use, the reviewed studies didn’t compare the effectiveness of morning-after pills to other forms of birth control. Reuters reports:

[T]aking a morning-after pill at the time of intercourse is not as effective as methods women use on a longer basis, such as patches or regular birth control pills, said Dr. Deborah Nucatola of Planned Parenthood of America, who was not involved in the study.

Even so, there are reasons a woman might want to use the morning-after pill just before or after sex instead of taking birth control all the time, she told Reuters Health — for instance, if she doesn’t have sex frequently.

Further longer-term research is needed to determine how effective this off-label use of morning-after pills may be, and whether women would want to use them as regular birth control. About 22% of women in the studies experienced irregular bleeding, which is a common side effect of the morning-after pill, but most said it wasn’t a reason not to use the drug. (More on To Slash the Abortion Rate, Dole Out Birth-Control Pills a Year at a Time)

Women who smoke and are over 35 years old, or have a family history of blood-clotting conditions should carefully consider the risks of any hormonal birth control.

The new study was published in the journal Obstetrics and Gynecology.

Related Links:

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