Depo Provera May Raise STD Risks
Injectable Contraceptive Linked to Higher Chlamydia and Gonorrhea Risk
Aug. 23, 2004 -- Women who use the injectable contraceptive
Depo Provera may face a higher risk of some sexually transmitted diseases,
according to a new study.
Researchers found women who used Depo Provera were more than
three times as likely to become infected with chlamydia or gonorrhea over the
course of a year than women who used birth control pills or nonhormonal
"These findings underscore the need to counsel all sexually
active women who use [Depo Provera] and who are not in a mutually monogamous
relationship to use condoms consistently and correctly," says researcher
Charles Morrison, PhD, of Family Health International in Research Triangle
Park, N.C., in a news release. "For sexually active women not in a mutually
monogamous relationship, limiting the number of partners may also help to
reduce the risk."
Researchers say an estimated 20-30 million women use Depo
Provera, and its use is growing quickly in many developing countries with a
high prevalence of sexually transmitted infections. The contraceptive consists
of a long-acting hormone that is injected into either the arm or buttocks four
times a year.
Like all hormonal contraceptives, Depo Provera does not provide
protection against sexually transmitted diseases (STDs). Chlamydia and
gonorrhea are among the most common STDs caused by bacteria and about 150
million new cases of chlamydia and gonorrhea are reported worldwide each year.
They are responsible for a number of conditions including pelvic inflammatory
disease and infertility.
No Greater Risk With Birth Control Pills
In the study, which appears in the September issue of
Sexually Transmitted Diseases, researchers compared the effect of oral
contraceptives and Depo Provera on rates of chlamydia and gonorrhea in a group
of 819 women. Most of the women were single, 43% were black, and the average
age was 22.
Over the course of a year, the study showed that 45 women
developed chlamydia or gonorrhea.
Women who used Depo Provera were 3.5 times more likely to have
an STD compared with women using a nonhormonal contraceptive.
Researchers found no significant increase in STD risk among
women who used birth control pills.
Researchers say the study wasn't able to determine how use of
Depo Provera might increase the risk of infection with a STD. But they say it's
possible that the injectable contraceptive may decrease estrogen levels and
lead to an increased susceptibility to vaginal and cervical infections.