Correspondence

Emergency Postcoital Contraception

N Engl J Med 1998; 338:476-477February 12, 1998

Article

To the Editor:

We were very pleased to see Glasier's timely and thorough discussion of emergency postcoital contraception (Oct. 9 issue).1 However, two points dealing with missed oral-contraceptive pills are troublesome.

First, the instructions for taking missed pills that are shown in Figure 1 are those used in the United Kingdom, not in the United States, and therefore may be confusing to readers accustomed to the instructions approved by the Food and Drug Administration now included in all U.S. pill packets. Physicians have no way of knowing why the instructions differ from those used in the United States or whether to apply them when making decisions about prescribing emergency contraception or when counseling their patients about handling missed pills in general.

Specifically, the U.K. instructions for missed pills advise using back-up contraception for the next seven days if a single pill is taken 12 hours late. This would suggest the need for emergency contraception if back-up contraception was not used during the seven-day period after any one pill is taken more than 12 hours late. In contrast, the instructions approved by the Food and Drug Administration do not advise the use of back-up contraception unless pills are missed on two or more consecutive 24-hour days.

Second, Dr. Glasier's statement that “emergency contraception is not usually indicated when one or more oral-contraceptive pills have been forgotten, because there are established and effective rules for the use of a barrier method as secondary prevention under these circumstances” could be misinterpreted. The reason most women need emergency contraception is that they have not followed “established and effective rules” for regular — or back-up — contraception. For example, in a recent study of 103 women taking oral-contraceptive pills, back-up contraception was used in only 3 percent of the acts of intercourse in which it was indicated. In addition, that statement diverts attention from a situation in which emergency contraception may prevent a pregnancy that would otherwise result from an act of intercourse before the pills were missed (e.g., an active pill is taken on schedule on Saturday night, intercourse occurs on Sunday evening, and active pills are missed on Sunday, Monday, and Tuesday nights).

Linda S. Potter, Dr.P.H.
James Trussell, Ph.D.
Princeton University, Princeton, NJ 08544

Lisa Rarick, M.D.
Food and Drug Administration, Rockville, MD 20857

1 References