- The study was valid, with appropriate concealed randomization and
double blindedness with identical pill appearance in both groups.
The subjects were analyzed based on intention to treat with those who
had violated study protocol or who were pregnant before the emergency
contraception was taken being analyzed in their appropriate groups.
The loss to follow-up rate was low (2.2%) and likely insignificant to
trial outcome. The subjects were similar at the start of the trial
and treated equally throughout.
- The Yuzpe regimen is readily available in the United States (equivalent
to two Ovral pills taken at presentation and again twelve hours later).
Levonorgestrel alone is not available in the United States, but norgestrel
alone is (marketed as Ordette). In order to take the appropriate
dose of norgestrel to meet the trial doses of levonorgestrel (its metabolite),
one would have to take twenty tablets of Ordette at presentation and
again twelve hours later. In Europe and Asia, these regimens are
both available in single pill formulations.
- In the United States, assuming a single pack of OCPs cost $30, the
cost to prevent one pregnancy using the Yuzpe regimen would be $720.
The cost to prevent one pregnancy using the levonorgestrel regimen would
be $900 (higher because two packs would need to be used). If emergency-contraceptive
formulations existed in the U.S., it would presumably be far less expensive.
- Safety and teratogenicity were not reviewed, though one might extrapolate
from data on standard doses of hormonal contraception that the risks
are low (and probably lower for those taking a progestin-only regimen).
- While method of action was not addressed in this article, most pregnancies
are thought to be prevented with either regimen by disrupting ovulation.
Thus emergency contraception is truly a method of contraception, rather
than an abortifacient.
- Randomised controlled trial of levonorgestrel versus the Yuzpe regimen
of combined oral contraceptives for emergency contraception. Task
Force on Postovulatory Methods of Fertility Regulation The Lancet
352 (9126): 428-33, 1998.
- Wilcox AJ, Weinberg CR, Baird DD. Timing of sexual intercourse
in relation to ovulation: effects on the probability of conception,
survival of the pregnancy, and sex of the baby. New England
Journal of Medicine 333: 1517-21, 1995.
- Glasier A. Drug Therapy: Emergency Postcoital Contraception.
New England Journal of Medicine 337(15): 1058-1064, 1997.
- Trussell J, Ellertson C, and Stewart F. The Effectiveness of
the Yuzpe Regimen of Emergency Contraception. Family Planning
Perspectives. 28(2): 58-64, 87, 1996