July 12, 2007 -- Using a diaphragm doesn't appear to help HIV prevention in women, researchers report in tomorrow's online edition of The Lancet.
The finding comes from a study of more than 4,900 sexually active women in South Africa and Zimbabwe, where about one in five adults is infected with HIV.
The researchers included Nancy Padian, PhD, of the University of California, San Francisco.
They point out that in southern Africa, because of gender inequality and social or cultural constraints, "women are often unable to negotiate the use of male condoms, a key component of HIV prevention strategies."
Padian's team tested the idea that diaphragms, which are a barrier contraceptive, might reduce HIV infection in women -- and give women the power to help protect themselves from HIV.
HIV Prevention Study
First, the women took HIV tests to make sure they weren't already HIV-positive.
Next, the researchers split the women into two groups. They gave all of the women in both groups an unlimited supply of condoms for their male partners to use and counseled all of the women about HIV prevention.
In addition to the condoms, one group of women got diaphragms and lubricant gel. For comparison, the other group of women didn't get diaphragms.
HIV prevention counselors stressed to the women in the diaphragm group that they should use the diaphragms with, not instead of, male condoms.
The women were followed for up to two years. During that time, they got HIV tests every three months.
No HIV Prevention Seen With Diaphragms
The study shows no difference between the two groups in the rate of new HIV infections.
Each year, approximately 4% of the women in both groups were newly diagnosed with HIV infection.
Women in the diaphragm group reported less condom use by their male partners, compared with women who didn't get diaphragms. The researchers aren't exactly sure why that is, but they have several theories.
Perhaps the women thought the diaphragm was sufficient for HIV prevention, though they had been told otherwise. Or maybe the women in the comparison group overestimated their partners' condom use, note Padian and colleagues.
"Unfortunately, our results add to the growing body of HIV-prevention trials that have failed to show a protective effect of interventions," write the researchers.
They call the results "disappointing," since "women who cannot convince their male partners to use condoms are still in urgent need of a female-controlled method of protection."