In an editorial review published in the September 7, 2001 issue of the journal, AIDS, lead author Thomas R. Moench, MD, medical director at ReProtect, LLC, Baltimore, and senior author Nancy Padian, PhD, professor of obstetrics and gynecology and director of international programs at UCSF’s AIDS Research Institute, argue that the diaphragm, a once popular birth control method whose use has declined drastically since the introduction of oral contraceptives, deserves a second look from researchers.
“Female-controlled HIV prevention technologies are desperately needed, especially in the developing world where I do much of my work,” said Padian. “Women often do not have the power to control when or how they have sex. A diaphragm can be used without their partner knowing about or needing to consent to its use.”
The review hypothesizes that the cervix is a “hot spot” in terms of susceptibility to HIV infection and that physical barrier devices like the diaphragm that protect the cervix may have a greater potential than previously thought. “The epithelial surface of the cervix is very thin and fragile—it can bleed spontaneously or with minor trauma. The surface of the vagina is much thicker. It’s covered with something more like skin. Also, the cervix has more cells with HIV specific receptor sites and these cells appear to reside closer to the cervix’s surface than in the vagina,” said Moench.
Another factor leading to increased susceptibility noted in the review is the peristaltic contractions of the uterus that actually aspirate or draw fluids up into the upper genital track. The upper genital track has been shown to be very susceptible to HIV and sexually transmitted diseases (STDs). This rapid upward movement of fluid is thought both to enhance fertility and to transport HIV and STD causing pathogens. The diaphragm is a barrier that blocks the transport of fluids and keeps them within the vagina where a microbicide—a topical foam, gel, or lotion that kills the HIV on contact before it infects—could have greater effect.
Using microbicides concurrently with diaphragms could increase the HIV preventive qualities of both. “We know that the effectiveness of spermicides—topically applied, pregnancy preventing, sperm killers—is increased one and one half times when used in conjunction with a diaphragm. We could reasonably expect a similar result when the device is used in combination with microbicides,” said Moench.
Moench also noted that the willingness of women to use a diaphragm is an issue inhibiting research on its use to prevent HIV. Few women in the developed world currently use a diaphragm as a means of contraception. “However, in 1955 before the introduction of the pill, a study by Ryder and Weston showed the 25% of U.S. women using contraceptive methods used diaphragms. We expect the acceptability of diaphragms would be high again if they were shown to prevent HIV,” he said.
“As we look at HIV prevention in the context of the enormous number of women worldwide at risk for infection, we need to shift our thinking and recognize that HIV prevention is an aspect of reproductive health. If we then make the analogy with contraception, we see that women are offered and use a variety of different methods,” said Padian, who is currently conducting a study of diaphragm acceptability in Zimbabwe with very promising initial results.
“In fact, short of a vaccine—something years down the road—there will be no ‘magic bullet’ or ‘one size fits all’ solution. We need to consider every technology, especially something like the diaphragm that has been used safely for over one hundred years,” added Moench.
Co-author of the review is Tsungai Chipato, MD, professor of obstetrics and gynecology at the University of Zimbabwe, Harare, Zimbabwe.
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