Getty: Peter Ardito

Getty: Peter Ardito

Practicing safe sex is the first line of defense against sexually transmitted diseases (STDs), along with making sure you and your partner get tested for HIV so that you know your status.

But many women do not realize that it’s also important to keep your body’s natural defenses as strong as possible. When it comes to STDs, that means maintaining the genital, mucosal barrier. HIV and other sexually transmitted viruses must penetrate the genital mucosal barrier to infect you, so identifying threats to the barrier was the focus of a recent study.

New research, from Ohio Wexler University, suggests that certain types of hormonal birth control may weaken the mucosal barrier, making you more susceptible to sexually transmitted viruses, including HIV.

African American women continue to fight a tough battle against HIV infection and AIDS. Between 2005 and 2014, the rate of HIV/AIDS among black women fell 42 percent, but it is still higher than the rate among other groups of women. We are at particularly high risk because the rate is so high among African American men Among all African Americans diagnosed with HIV in 2014, an estimated 73 percent (14,305) were men and 26 percent (5,128) were women.

IUDs and Injectables Tested

Researchers injected female mice with depot medroxyprogesterone acetate (DMPA used in the contraceptive depo provera) or levonorgestrel (LNG used in the Mirena brand intrauterine device). In the mice treated with DMPA or LNG, the barrier protection in the genital tract weakened, decreasing protection against viral infections.

Surprisingly, the researchers found that on the other hand, additional studies showed that combined treatment with DMPA and intravaginal estrogen prevented mice from acquiring herpes simplex virus type 2 by restoring the genital mucosal barrier, a first-line of defense against all sexually transmitted infections.

Similar findings in Women

“Our findings provide new biological plausibility for the connection between DMPA and increased susceptibility to genital infection suggested by many clinical studies,” said Thomas L. Cherpes, MD, an associate professor in the Departments of Microbial Infection and Immunity and Obstetrics and Gynecology at The Ohio State University College of Medicine, in a university interview. “They also identify that LNG may similarly enhance susceptibility to viral infections.”

While mice are used for any study that involves infecting a living organism with HIV, the researchers added that “our evaluation of cervical biopsy tissue from women before and one month after initiating DMPA revealed barrier protection was diminished by treatment identical to the change seen in the treated mice,” said Nirk Quispe Calla, MD, lead author of the publication.

The research is just one more indicator that women need to consider many factors when choosing a form a birth control. Altering the body’s natural hormonal balance may have unforeseen consequences and effects on immune health.