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Preventing HIV Transmission During Pregnancy
One of the routine screening tests in pregnancy is the HIV test. Human Immuno-deficiency Virus (HIV) is the virus responsible for AIDS. Although many people assume that AIDS predominantly affects homosexual men, women account for a growing share of affected individuals. In the United States, women account for 27 percent of new AIDS cases.

Women become infected with HIV if they come in contact with body fluids of an infected person. In women, HIV is most commonly spread through sexual relations; 78 percent of new infections result from unprotected sexual contact with an infected partner. The virus can enter the body through the lining of the vagina, vulva, rectum or mouth.

HIV infections are also spread through sharing drug needles or syringes. However, blood transfusions are an unlikely source of infection in the United States as all donor blood is screened for HIV and/or is heat-treated to kill the virus. Infants can acquire HIV during pregnancy, during the birthing process or from infected breast milk.

A woman who is HIV-positive may appear perfectly healthy. While a new infection may cause a brief, flu-like illness, many individuals are not symptomatic for months. The virus affects the immune system slowly over time.

AIDS is diagnosed when a person’s immune system is impaired by laboratory measures, or when the body is no longer able to fight certain opportunistic infections or resist the growth of tumors. Symptoms may include fatigue, fever and weight loss. However, it can take months or years before a person with HIV infection develops AIDS. Thus, a pregnant woman could unknowingly carry the HIV virus and pass this to her child, either during pregnancy, delivery or postpartum.

If a pregnant woman is HIV positive, there are ways to reduce her chance of transmitting HIV to her child. Treatment includes anti-retroviral medication, good nutrition and possibly a Caesarean delivery. A woman who does not receive treatment for HIV during pregnancy has a 25 to 30 percent chance of passing the infection to her child. With appropriate treatment, the risk is lowered to 2 percent. Following delivery, an HIV positive woman is encouraged to provide formula rather than breast milk to her infant in order to prevent postpartum transmission of the virus.

All pregnant women are screened for HIV, using either an “opt-in” or “opt-out” approach to testing. Most states utilize opt-out HIV screening. With this approach, HIV is included in a battery of routine labs for all prenatal patients. All pregnant women are tested for HIV unless they refuse to be screened. The opt-in approach requires verbal or written permission before HIV testing is performed.

If an HIV test is positive, a second test is requested to confirm the first test results. If the HIV test is negative, it means that a woman does not have antibodies to HIV. It should be noted that it takes up to six months to develop antibodies to HIV following an initial infection. Therefore, if a woman is at risk for HIV infection, it is wise to repeat the test in a few months. Selected risk factors for HIV are described below.

Risk Factors for HIV:
  • Sexual contact without a latex condom
  • Sex with more than one partner
  • Sexual contact with a partner whose sexual and drug use history is unknown
  • Using injectible drugs, especially if needles or syringes are shared


For more information on HIV/AIDS, consult the following websites:

US Department of Health and Human Services http://www.aidsinfo.nih.gov

National Institute of Allergy and Infectious Diseases http://www.niaid.nih.gov/publications/aidsfact.htm

Centers for Disease Control and Prevention http://www.cdc.gov/hiv/

Laura E. Stachel M.D. Obstetrician & Gynecologist