HIV/AIDS Causes & Risk Factors HIV in Heterosexual Couples Who is at greater risk? By Mark Cichocki, RN Mark Cichocki, RN LinkedIn Twitter Mark Cichocki, RN, is an HIV/AIDS nurse educator at the University of Michigan Health System for more than 20 years. Learn about our editorial process Updated on April 18, 2020 Medically reviewed Verywell Health articles are reviewed by board-certified physicians and healthcare professionals. These medical reviewers confirm the content is thorough and accurate, reflecting the latest evidence-based research. Content is reviewed before publication and upon substantial updates. Learn more. by Latesha Elopre, MD, MSPH Medically reviewed by Latesha Elopre, MD, MSPH LinkedIn Latesha Elopre, MD, is a board-certified internist specializing in HIV. She is an assistant professor of infectious diseases at the University of Alabama at Birmingham. Learn about our Medical Expert Board Print The transmission and acquisition of HIV from vaginal intercourse are high in cases of condom-less sex, both in women and men. While the risk tends to be higher among women due to biologic vulnerability (including the greater mass of mucosal tissues which HIV can breach), men are also at risk with everything from concurrent sexually transmitted diseases (STDs) to circumcision status adding to that risk. Noviembre Anita Vela / Moment / Getty Images Transmission Risk in Women HIV can be found in the blood, semen, pre-seminal fluid ("pre-cum"), or vaginal fluid of a person infected with the virus. The lining of the vagina can tear and allow HIV to enter the body, as well as through absorption of HIV through the mucous membranes that line the vagina and cervix. When HIV is exposed to these tissues, the localized infection is attacked by first-line immune cells, including macrophage and dendritic cells. The activation of these cells sparks a reaction from the immune system in which specialized defensive cells, including CD4 and CD8 T-cells, are spurred to the fight. Ironically, it is the CD4 cells that HIV preferentially targets for infection. If this occurs and the first-line defense are unable to contain the HIV invaders, an exposure becomes more than just exposure. It becomes an infection. Transmission Risk in Men Through the male is at somewhat less risk for HIV than his female sexual partner, HIV can enter either through his urethra (the opening at the tip of the penis) or through small cuts or open sores on the penis. Additionally, men who are uncircumcised tend to be more vulnerable to HIV than men who are circumcised. The bacterial population that exists beneath a foreskin can thrive due to the moist environment. The immune system naturally responds by triggering a modest immune defense to keep an infection at bay. Again, ironically, CD4 cells can be called to the front lines of defense, making transmission all the easier. Sexually Transmitted Diseases Sexually transmitted diseases work more or less in the same way. Beyond open ulcerative sores that can facilitate an easy route into the bloodstreams (from STDs like syphilis or herpes simplex), other infections spur a localized immune response, exponentially increasing the likelihood of HIV transmission or acquisition well beyond what might occur if there was no HIV. Preventing HIV Transmission If you choose to have vaginal intercourse, use a latex condom to protect both you and your partner from the risk of HIV and other STDs. Studies have shown that latex condoms are very effective when used correctly and consistently. If either partner is allergic to latex, plastic (polyurethane) condoms for either the male or female can be used. (Avoid lambskin condoms which do not offer protection from HIV and STDs). Additionally, partners can significantly reduce HIV by two additional preventive strategies: An HIV-positive partner, male or female, should be placed on antiretroviral therapy to achieve full suppression of the virus to undetectable levels. If this is achieved, the risk of transmission to an uninfected partner can drop to zero, if the partner has sustained viral suppression for at least six months. Learn more about HIV treatment as prevention (TasP). Any HIV-negative partner, male or female, can opt to take HIV pre-exposure prophylaxis (PrEP), a daily antiretroviral tablet which can reduce the risk of acquiring HIV from anywhere from 70-90%. Learn more about how to use Pre-Exposure Prophylaxis (PrEP). Was this page helpful? Thanks for your feedback! Get information on prevention, symptoms, and treatment to better ensure a long and healthy life. Sign Up You're in! Thank you, {{form.email}}, for signing up. There was an error. Please try again. What are your concerns? Other Inaccurate Hard to Understand Submit 0 Sources Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy. Liu, C.; Hungate, B.; Tobian, A.; et al. "Male Circumcision Significantly Reduces Prevalence and Load of Genital Anaerobic Bacteria." mBio. February 15, 2013; 4(2): e00076-13. U.S. Centers for Disease Control and Prevention (CDC). "Interim Guidance for Clinicians Considering the Use of Preexposure Prophylaxis for the Prevention of HIV Infection in Heterosexually Active Adults." Morbidity and Mortality Weekly Report (MMWR). August 10, 2012; 61(31):586-589. U.S. Centers for Disease Control and Prevention (CDC). "Vital Signs: HIV Prevention Through Care and Treatment - United States." Morbidity and Mortality Weekly Report (MMWR). December 2, 2011; 60(47):1618-1623.