Eighty-five percent of women have been on the receiving end of oral sex, according to a national study released over the summer. (That's equal to the number of guys who have received oral sex as well.)

Based on the study results, it stands to reason that oral pleasure is a standard part of most couples' sexual repertoire.

But even though the practice is so widespread, there's not a lot of clear information out there about the potential health risks if you're getting, not giving.

Safe sex guidelines tend to focus on vaginal and anal intercourse. That made us wonder: Does receiving oral sex pose any threat to the health of your vagina?

“Oral sex isn’t necessarily bad for your vagina,” says Alyssa Dweck, MD, a New York-based ob-gyn and co-author of The Complete A to Z for Your V. “There’s a natural environment of bacteria in the mouth and a natural environment of bacteria in the vagina, and for people with normal, healthy immune systems, there shouldn’t be an issue,” she tells Health.

While your partner's saliva is probably safe, his mouth, lips, and throat may not be. If he has a cold sore or feels one coming on—and his lips make contact with the skin on and around your vagina—he may pass it on to you.

Cold sores are caused by the herpes virus, so his oral herpes can turn into genital herpes for you. “A lot of people don’t think about the fact that if a partner has one of these and then performs oral sex on a woman, she has the potential of developing a genital herpes infection,” explains Dr. Dweck.

Herpes isn't the only STD a woman can pick up after being orally pleasured. Gonorrhea and chlamydia can be passed on if your partner is infected with either of these bacterial STDs in his throat. HIV is another threat.

Should an HIV-positive partner go down on you, viral particles could enter your bloodstream through an abrasion or sore in your vagina and pass HIV to you, says Dr. Dweck.

Then there's the risk of contracting HPV, or the human papillomavirus. While the likelihood of transmission from oral sex isn't known, according to the Centers for Disease Control, some studies suggest that this is possible. If your partner has HPV in his throat and he carries one of the viral types linked to cervical cancer, he may pass the virus on to you and increase your risk of cervical cancer.

And just for good measure, partners on the receiving end can also end up transmitting an STD or other infection. “On the flip side, say a woman has her period and her partner is performing oral sex on her when there’s blood there,” says Dr. Dweck. “That’s not a wise idea because again, an infection could be transmitted via blood or bodily fluid contact.”

So if getting oral sex is something you enjoy, you can never be too cautious. “We usually recommend universal precautions for oral and genital sex,” says Dr. Dweck. If you don't know your partner's STD status, she encourages wearing a condom during intercourse.

During oral sex, cover your vagina with a dental dam—a thin piece of latex placed over the vulva. This way, your partner's tongue and mouth can't make direct skin contact with your vaginal area.

“People usually look at me like I have three heads when I say this, but something like a dental dam provides a very thin but safe barrier between the oral and vaginal cavities,” explains Dr. Dweck. It's not exactly sexy, we get it. But better safe than sorry, right?