Pre-Conception: Human Immunodeficiency Virus (HIV)
Testing for human immunodeficiency virus (HIV) infection has become routine prenatal care in the United States. Some states even require that all pregnant women and/or their newborns be tested. Treatment begun during pregnancy can prevent the disease in the child and improve the mother's health as well. Even so, not all women receive routine prenatal care or are offered the test during pregnancy, acknowledges the U.S. Centers for Disease Control and Prevention (CDC), and some women do not agree to have the test. Ideally, the woman will have the blood test as part of her pre-conception care or early in the pregnancy. This best protects the mother and baby.
- Screening the mother: All pregnant women in the United States should be counseled about HIV early in their pregnancy and receive voluntary HIV testing to protect the child’s health. This is the recommendation of many groups, including the U.S. Public Health Service, American Academy of Pediatrics, American College of Obstetricians and Gynecologists, and U.S. Preventive Services Task Force. Repeating the test in the third trimester is of value to those at high risk for HIV infection.
- Screening the baby: In the United States, if the mother’s HIV status is not determined before or during pregnancy or during labor and delivery, healthcare practitioners recommend that the newborn be given an HIV test within 24 hours of the birth (in a few states, this is a requirement; see Newborn Screening). Treatment begun within 48 hours of birth helps prevent a baby who was exposed to the virus from becoming infected.
HIV is the virus that causes AIDS (acquired immunodeficiency syndrome). If a pregnant woman is infected with HIV, the virus can be passed to and infect her baby.
The screening tests detect HIV antigen (p24) and/or HIV antibodies in the blood. The combination HIV antibody and antigen test is the recommended screening test for HIV. It is available only as a blood test. By detecting both antibody and antigen, the combination test increases the likelihood that an infection is detected soon after exposure. Some screening tests detect only HIV antibody. These tests are available as blood tests or tests of oral fluid.
If the screening test is positive, it must be followed by a second antibody test that is different than the first test. If the second test does not agree with the first test, then a third test is performed that detects the genetic material (RNA) of the virus.
If a woman's confirmatory tests indicate an HIV infection, she will want to consult with her healthcare provider before becoming pregnant about the risks of infecting a baby and the effects of the pregnancy on her health. Treatment of HIV-infected mothers during pregnancy, precautions at birth, and avoiding breast-feeding can minimize the risk of passing the infection from mother to child. Giving the antiretroviral drug zidovudine intravenously during labor and delivery and also to the newborn twice a day by mouth for 6 weeks reduces the rate of transmission from 25-33% to about 1-2%. A combination of antiretroviral therapies is most effective at reducing the risk of HIV transmission to the baby.
A negative test for the antibody to HIV may mean that there is no infection or that a sufficient amount of the antibody has not yet been produced to be detected. If a woman participates in high-risk activities that may transmit HIV, such as unprotected sexual contact or intravenous drug use, she should be retested one or more additional times during the pregnancy.