Here is a very recent letter to the editor in the Journal Pediatrics that poses some of the same questions that I have regarding the efficacy of emergency contraception (Pediatrics 117:4 April 2006, p1448).
To the Editor.-
The American Academy of Pediatrics Committee on Adolescence policy statement on emergency contraception1 reports the effectiveness of the Yuzpe regimen (ethinyl estradiol and levonorgestrel) in terms of a pregnancy reduction of 70% to 80% and of levonorgestrel-only emergency contraception of 85%. These estimates are outdated. Using current methods for estimating effectiveness, the effectiveness rates seem to be in the range of 50% to 66% and 72% to 80%, respectively.2-5 Because there are no randomized trials with a placebo arm, considerable uncertainty remains about the effectiveness of emergency contraception.3,5
The policy statement also proposes that "[e]mergency contraception has tremendous potential to reduce unintended pregnancy rates in teens and adults." This statement remains, as yet, a hypothesis that is unsupported by empirical evidence. Several studies have failed to document a decrease in rates of unintended pregnancy or abortion in populations that are provided with advance access to emergency contraception.6-8 This suggests that the studies that have demonstrated no changes in sexual behavior with advance access (other than increased use of emergency contraception) have used inadequate surrogate end points or have failed to detect small changes in sexual behavior that were nevertheless sufficient to negate any decrease in unintended pregnancy.
Joseph B. Stanford, MD, MSPH
Department of Family and Preventive Medicine
University of Utah
Salt Lake City, UT 84108
Rafael T. Mikolajczyk, MD
Department of Public Health Medicine
School of Public Health
University of Bielefeld
D-33501 Bielefeld, Germany