[T]he Centers for Disease Control and Prevention reported recently that one in nine sexually active women, or 5.8 million women, has used emergency contraceptive pills, such as Plan B. Emergency contraception is a woman’s back-up method to prevent an unwanted pregnancy, and women report using it when they feel their contraceptive method has failed, such as a broken condom, or they do not use a regular contraceptive like birth control pills.
The latest scientific evidence shows that Plan B works mainly by delaying ovulation — not by affecting a fertilized egg.
Some conservative politicians have been stating publicly that emergency contraceptive pills (ECPs), such as Plan B, cause abortions. They may believe that life begins at conception (fertilization of the egg by the sperm) and argue that ECPs disrupt a fertilized egg’s ability to implant in the uterus, which they consider equivalent to abortion. The American Congress of Obstetricians and Gynecologists and experts from the Food and Drug Administration and the National Institutes of Health consider a pregnancy to be established when a fertilized egg settles itself on the wall of the uterus — implantation. A woman is most likely to become pregnant when she ovulates, which is usually about two weeks before her next period. Sperm can live for up to three days. So, if an egg is fertilized, there are still possibly six to 12 days before the implantation may take place.
When ECPs were first developed and information about them was submitted to the FDA for market approval, the drug manufacturers included mention of every possible mechanism on how the pill might work to prevent pregnancy. This included wording about preventing or delaying ovulation, making the sperm or egg less able to meet, and possibly preventing implantation. However, the latest scientific evidence has shown that ECPs such as Plan B mainly work by delaying ovulation — Plan B does not affect implantation and has no effect on existing pregnancies. Several prominent researchers have stated that if in fact Plan B disrupted implantation, it would be 100 percent effective at preventing a pregnancy, and that is not the case. Continue reading