Plan B Doesn’t Cut Pregnancy Rates
Study: Pregnancy Numbers Remain Steady After Easier Access to Morning-After Pill
WebMD News Archive
April 17, 2007 - So-called morning-after contraception works for individual
women, but it isn’t working to lower unwanted pregnancy rates at the population
level, an analysis of the research shows.
Researchers concluded that easy access to emergency contraception (involving
higher doses of hormones found in birth control pills) does not reduce
unintended pregnancy rates.
The analysis of eight studies involving more than 6,000 women revealed that
pregnancy rates were the same for women who did and did not receive an advance
supply of emergency contraception along with counseling about how to use the
Late last summer the FDA agreed to over-the-counter sales of the emergency
oral contraceptive sold as Plan B to women aged 18 and older.
Supporters of the move contended that easy access to Plan B would help
reduce unintended pregnancy rates, while critics charged that it would
encourage promiscuity and increase the likelihood of women having unprotected
Neither conclusion is supported by the research, one of the authors of the
analysis tells WebMD.
“The women who had the emergency contraception on hand did use it more
often, but that didn’t translate into a decrease in pregnancy rates at a
population level,” says Chelsea Polis of the Johns Hopkins Bloomberg School of
Wasn’t Used When Needed
When used correctly, morning-after contraception is very effective for
preventing pregnancy. The high-dose pills should be taken as soon as possible
after unprotected sex, but the strategy can prevent pregnancy for up to five
days after intercourse. Plan B must be used within 72 hours of intercourse.
Polis says it is clear that the study participants who had Plan B or another
emergency oral contraceptive on hand were not using emergency contraception
every time they had unprotected sex.
“A high percentage of women who became pregnant hadn’t used [emergency
contraception] when they needed it,” she says.
Four of the eight studies included information on women who had the
emergency contraception on hand but got pregnant anyway. In these
studies, 64% to 79% of the women said they did not use emergency contraceptives
in the cycle in which they became pregnant.
The studies included women living in the United States, India, and
Polis says the findings should not be interpreted as meaning that emergency
contraception isn’t useful or that efforts to make it more readily available
are not important.
And the research makes it clear that having emergency contraception on hand
does not increase risky sexual behaviors, she says.
There was no difference in sexually transmitted infection rates between
study participants who had advanced provision emergency contraception and those
in the control arm of the study.
Lessons From France
Emergency contraception has been available without a prescription in France
since 1999, longer than any other country. Princeton University researcher
Caroline Moreau, PhD, was one of the first to study the effectiveness of the
birth control method at a population level.
She found that a 72% increase in emergency contraceptive use among French
women over a five-year period did not have a measurable impact on abortion
When women seeking abortions were asked why they hadn’t used emergency
contraception, most said they had not known they were at risk for pregnancy,
Moreau tells WebMD.
“While enhanced availability of emergency contraception is certainly an
important measure to promote its use in case the need arises,
misrepresentations of pregnancy risk may prove to be the strongest barrier to
its use, thus limiting the possibility of its effect on unintended pregnancy
rates at the population level,” she notes.