Depo Provera Appears to Increase Risk for Chlamydial and Gonococcal Infections
The injectable contraceptive depot-medroxyprogesterone acetate
(DMPA) appears to increase a woman’s risk of acquiring the
sexually transmitted infections chlamydia and gonorrhea by approximately
three fold when compared to women not using a hormonal contraceptive,
according to a study jointly funded by the National Institute of
Child Health and Human Development (NICHD) at the National Institutes
of Health and the U.S. Agency for International Development’s
Office of Population and Reproductive Health.
DMPA is marketed under the product name Depo Provera. The contraceptive
is injected into either the arm or buttocks four times a year.
The study was unable to determine why DMPA might increase the risk
for these infections.
“These findings underscore the need to counsel all sexually
active women who use DMPA and who are not in a mutually monogamous
relationship to use condoms consistently and correctly,” said
the study’s first author, Charles Morrison, Ph.D., of Family
Health International in Research Triangle Park, North Carolina.
“For sexually active women not in a mutually monogamous relationship,
limiting the number of partners may also help to reduce the risk.”
The study appears in the September Sexually Transmitted Diseases.
The researchers also tested another type of contraceptive formulation,
oral contraceptives containing both estrogen and progestin. The
researchers concluded that oral contraceptives do not appear to
significantly increase the risk of chlamydial infection and gonorrhea.
To conduct the study, the researchers recruited women from two
Baltimore, Maryland area clinics. One clinic was within the city
of Baltimore and served a predominantly African American clientele.
The other was in the Baltimore suburb of Towson and predominantly
served white, college-age women. The women chose whether they wanted
to use DMPA, oral contraceptives, or a non-hormonal contraceptive
Of the 819 women included in the study’s final analysis,
77 percent were single, 75 percent had never given birth, and 79
percent were high school graduates. Roughly 52 percent were white,
43 percent were African American, and the remaining women were of
other racial or ethnic origins. Study participants ranged in age
from 15 to 45 years. After enrolling in the study, they were tested
for chlamydial and gonococcal infection after three, six, and 12
The study compared three groups of women, those starting oral contraceptives,
those starting DMPA injections, and those women who did not use
hormonal contraceptives. By the time the study had ended, 45 women
had developed either a chlamydial or gonococcal infection. The researchers
estimated that women using DMPA had approximately 3½ times
the risk of developing a chlamydia or gonorrhea infection than did
women who were not using a hormonal contraceptive.
The study was designed to examine the combined number of cases
of chlamydial and gonococcal infection and was not large enough
to calculate the risk for acquiring each infection separately, says
the study’s project officer, Joanne Luoto, M.D., of NICHD’s
Contraception and Reproductive Health Branch. The study was unable
to identify the means by which DMPA might increase the risk for
chlamydial or gonococcal infection.
Other authors of the study are at the University of North Carolina
at Chapel Hill; at Johns Hopkins University in Baltimore, Maryland;
and at Planned Parenthood of Maryland in Baltimore.
The NICHD is part of the National Institutes of Health (NIH), the
biomedical research arm of the federal government. NIH is an agency
of the U.S. Department of Health and Human Services. The NICHD sponsors
research on development, before and after birth; maternal, child,
and family health; reproductive biology and population issues; and
medical rehabilitation. NICHD publications, as well as information
about the Institute, are available from the NICHD Web site, http://www.nichd.nih.gov,
or from the NICHD Information Resource Center, 1-800-370-2943; e-mail