Have you or one of your friends ever been having sexual intercourse when unexpectedly the condom breaks?  Or, have you watched the macho stud in popular television shows or movies telling the innocent virgin that he does not have a condom, but everything will be ok?  These scenarios have become all too familiar to teenagers today.  What should you do if this happens to you or somebody you know?  With the famous “Morning After Pill,” technically called emergency postcoital contraception (E.P.C.), women can prevent unwelcomed pregnancies.  Though not flawless, this hormone-based pill is one of the most effective ways to prevent fertilization of the egg after having unprotected sex.  For the past 30 years researchers have concluded that the E.P.C. pill is only effective if taken within 3 days of having unprotected sexual intercourse.  However, a recent study found that the E.P.C. pill is effective up to 5 days after unprotected sex (Rodrigues et al., 2000).  Due to Duke’s rigorous and highly competitive academic environment, students enjoy time extensions.  Now, students can even get a 2-day time extension on the E.P.C. pill.

            For Rodrigues et al.’s study, 300 women (between the ages of 14 and 45) who needed emergency contraception were divided into two groups: those who had sex within less than 3 days (72 hours) of taking the E.P.C. pill, and those who had sex within more than 3 days of taking the pill.  The first group (<3 day group) was comprised of 131 women, and the second group (3-5 day group) had 169 women.  Each woman was given 4 tablets that contained two different types of hormones (2 were taken immediately and 2 were taken 12 hours later).  Three weeks later, the women returned to have a follow up pregnancy test performed.  During the three-week period between the first and second pregnancy test, the women were instructed not to have sexual intercourse.  Of the 300 women tested, only 4 became pregnant; one from the <3 day group (a pregnancy rate of 0.8%), and three from the 3-5 day group (a pregnancy rate of 1.8%).  These results strongly suggest that the E.P.C. pill does indeed work after 3 days.  

Rodrigues and her colleagues hypothesized that “the effectiveness of the treatment probably decreases as [the] upper limit is approached.”   In other words, the longer a woman waits to take the E.P.C. pill after sex, the less effective the pill will be.  However, this does not mean that the pill will not work.  If a female Duke student is too busy studying for a test and cannot buy an E.P.C. pill within 3 days of having sex, she should not worry.  There is still about an 87% chance that she will not become pregnant.  This percentage was computed by using the number of pregnancies that would have theoretically occurred if no form of contraception was used.  Rodrigues et al. determined how many women would have theoretically become pregnant by using “estimated probabilities of conception rates.”   Finally, Rodrigues et al. compared the results from their study to this estimated probability to find the percentage.  

            Be cautious when interpreting these results, however, because there are limitations to this study.  For example, how meaningful is the level of effectiveness? When calculating the level of effectiveness, Rodrigues et. al used probabilities and estimated numbers.  Rodrigues et al. stated that the pill is 87% effective after 3 days; however, this percentage is an estimate, thus it is not very meaningful.  How can Rodrigues et al. really know the number of women that would have “theoretically” become pregnant?  The answer is that they cannot know this number due to the fact that some women are not as fertile as others.  Genetics play a role in becoming pregnant; certain women are just unable to become pregnant, whereas others are highly fertile.  Rodrigues does not take this factor into account.  Also, there is no placebo group to compare the results to, and there is no way to tell if the women are being completely honost about their sexual activity.  Furthermore, this study does not take into consideration the effects of different forms of birth control on the morning after pill.    However, the study does serve as a good basis for informing women that E.P.C. pills can prevent pregnancies after 3 days. 

So to all the Duke students who could benefit from some extra time, the morning after pill can now be taken after 3 days.  While it is best and more effective to take the pill as soon as possible after unprotected sex, Duke students can feel more confident that it will still be effective within the 3-5 day window.  If you want to be 100% positive that you will not become pregnant, you should practice abstinence.  However, if you do choose to have sex, it is wise to use some form of birth control, like pills, the patch, or condoms.  If your original form of birth control fails, the morning after pill is a reliable backup method.                

Literature Cited

Rodrigues, I., Grou, F., Joly, J.  2004.  Effectiveness of emergency contraceptive pills