Although the use of birth control pills has been approved by the Food and Drug Administration for over fifty years, a small minority of Americans continue to oppose the practice on religious grounds. As a means of re-opening the question of whether oral contraceptives should be legal, some have claimed to make a distinction between the traditional pill and the “morning after”and “week after” pills. Those who make this distinction generally consider the latter pills to be work by inducing abortions.
An example of this distinction is the protest of retailer Hobby Lobby, claiming the right to prevent their insurer from paying for these two newer pills. Hobby Lobby distinguishes these two pills from other oral contraceptives, stating through their lawyers that, “The FDA-approved government birth control guide clearly states that these two drugs, the morning-after pill and the week-after pill, may prevent fertilized eggs from implanting in the womb, thus aborting the fertilized egg.”
The argument, therefore, is that special consideration should be given to these two drugs because they prevent fertilized eggs from implanting in the uterus. There is a problem with this reasoning, however. The hormone progesterone, which prevents implantation, is also present in most other oral contraceptives for women.
The morning after pill is sometimes call the Progestogen-Only Pill (POP), or the “mini-pill,” to distinguish it from the traditional " pill. What we usually just refer to as “the pill” is also known as the “combination birth control" pills, contains both progesterone and estrogen.
In the traditional pill, estrogen works in combination with progesterone to make it harder for sperm to fertilize an egg. But that isn’t all it does. According to the American College of Obstetricians and Gynecologists (ACOG), as well as most other experts, progesterone in the traditional pill also prevents pregnancy by preventing an egg’s implantation in the uterus if an egg is fertilized any way. The ACOG paper describing birth control can be downloaded here.
The religious freedom arguments under which religious employers try to oppose coverage of the morning-after pill are a separate issue, but the science behind the distinction of the “mini-pills” from the traditional pill is also highly questionable. No doubt, those opposed to abortion would argue that all oral contraceptives should therefore be outlawed, but since the overwhelming majority of Americans support the use of contraception, that might be a dubious political strategy.