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OB/GYN Editorial February 2002
Substantial Progress in Contraception
Ronald T. Burkman, MD
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For a number of notable reasons, 2001 was not one of America's "best
years." However, despite the tragic events of the year, there was
at least one area in the field of medicine that did show substantial
progress: contraception. For the first time in many years, a number
of new options became available such that, as 2002 unfolds, two unique
delivery systems for contraceptives, a transdermal and vaginal system,
will become available. Coupled with these two new systems, a new hormone-releasing
IUD and a monthly combination hormone injectable method are available.
In addition, even a well-established approach, such as the oral contraceptive,
has had alterations in its formulations including the introduction
of a somewhat unique progestin component.
An obvious question is whether there is a need for such new methods.
Unfortunately, despite slight improvements over the past decade
or so, data from one of the most recent surveys of contraceptive
practices show that about 50% of the pregnancies in the United States
are either unintended or unplanned.1 Further, about 40%
of women who didn't desire a pregnancy were not using contraception,
while the rest had been using some method in the month prior to
conception.2 The reasons for such findings are complex
but likely include inadequate education about both pregnancy risk
as well as risks and benefits of contraceptive methods, problems
with access, cost, concerns about side effects, difficulty in adhering
to a method correctly, and motivation. Dealing with the latter two
reasons may hold the most promise for some of the new methods. For
example, if one examines pregnancy rates for various contraceptive
methods, the typical use rates are highest for those methods that
require a daily activity (the oral contraceptive) or an activity
related to intercourse (the barrier methods).3 Methods
that require less-frequent motivation or dosing and are under substantial
control by providers (implants, IUD, and to some extent DMPA), have
typical use rates quite similar to the theoretical effectiveness
rates as one would expect. Three of the new methods (the monthly
injectable, vaginal ring and transdermal system) have dosing schedules
that vary from weekly to monthly. Thus, women using these methods
may remember or adhere better to this less-frequent dosing schedule.
There are some data to suggest this may be the case. For example,
in the clinical trials for both the vaginal ring and transdermal
contraceptive system, subjects reported perfect adherence to the
dosing schedules in about 90% of cycles.4, 5
In contrast, oral contraceptive users, when compared to users
of the transdermal contraceptive system in a randomized clinical
trial, reported perfect adherence in about 80% of cycles.4 Whether
"average users," as opposed to study subjects, will demonstrate
this degree of adherence remains to be seen. Finally, it also remains
to be seen whether the unplanned pregnancy rates will be impacted
in a favorable direction. However, as is true of most things in
life, simpler is often better; we can at least have some cautious
optimism.
References
- Henshaw SK. Unintended pregnancy in the United States. Fam
Plann Perspect. 1998;30(1):24-29, 46.10
- Piccinino LJ, Mosher WD. Trends in contraceptive use in the
United States: 1982-1995. Fam Plann Perspect. 1998; 30(1):4-10,46.
- Trussell J, Vaughan B. Contraceptive failure, method-related
discontinuation and resumption of use: results from the 1995 National
Survey of Thomas E. Nolan, MD, MBA
- Audet MC, Moreau M, Koltun WD, et al. Evaluation of contraceptive
efficacy and cycle control of a transdermal contraceptive patch
vs an oral contraceptive: a randomized controlled trial. JAMA
2001;285(18):2347-2354.
- Roumen FJ, Apter D, Mulders TM, Dieben TO. Efficacy, tolerability
and acceptability of a novel contraceptive vaginal ring releasing
etonogestrel and ethinyl oestradiol. Hum Reprod. 2001;
16(3):469-475.
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