Non-Sexual Transmission

HIV Screening During Pregnancy and Labor/Delivery

Since the first case of pediatric HIV infection was documented in 1984, there have been tremendous medical and public health achievements in preventing mother-to-child transmission of HIV. When the recommended antiretroviral and obstetric interventions are used, a woman who knows of her HIV infection early in pregnancy now has a less than 1% chance of delivering an infant with HIV. Before effective therapy, nearly 26% of infants of women with HIV were born with the infection.

However, approximately 2,800 undiagnosed women with HIV gave birth in the United States in 2000 (Office of the Inspector General, Department of Health and Human Services, 2002).

Ideally, all women should be screened for HIV during each pregnancy at their initial prenatal care visit or as early in pregnancy as possible. CDC also recommends a second HIV test during a woman’s third trimester for women who meet certain criteria, including those who: a) continue behaviors with a high risk for acquiring HIV, b) reside in specific high-prevalence jurisdictions, and c) receive health care in facilities with at least 1 diagnosed HIV case per 1,000 pregnant women per year.

Preventive antiviral therapy is most effective when it is initiated early in pregnancy. However, starting antiretroviral treatment during labor and delivery, or even providing it to the newborn within hours after birth, can reduce mother-to-child transmission by half (Wade et al. 1998; Kourtis et al. 2001; Guay et al. 1999). To maximize the benefit, it is important to obtain HIV test results for women in labor quickly in order to start antiretroviral therapy as soon as possible.

CDC recommends that clinicians test for HIV any newborn whose mother’s HIV status is unknown. For those women whose HIV status is unknown at labor, CDC recommends routine, rapid HIV testing. When the mother’s HIV status is unknown prior to the onset of labor and rapid HIV testing is not done during labor, CDC recommends rapid HIV testing of the infant immediately post-partum, so that antiretroviral prophylaxis can be offered to HIV-exposed infants. When intervention begins at the intrapartum (during labor or delivery) or neonatal periods, 9% to 13% HIV transmission rates are achievable based on clinical trial and observational data. These represent a 50% reduction in HIV transmission from rates that would be expected without intervention.

Rapid HIV tests that can be performed right in labor and delivery can yield results in less than 45 minutes. Such timely knowledge of the mother’s HIV status also provides opportunities for other interventions that reduce transmission, such as elective cesarean section, avoiding artificial rupture of membranes, and avoiding breastfeeding. CDC’s Mother-Infant Rapid Intervention at Delivery (MIRIAD) studypdf iconexternal icon proved rapid testing is feasible and effective.

If a pregnant woman is infected with HIV and screened prior to delivery, transmission to her infant can be prevented by the administration of antiretroviral medications and appropriate medical care if HIV is diagnosed at the time of labor.