1. HIV and Pregnancy

2. Introduction In the general obstetrical population in the United States, the frequency of HIV infection is about 1 per 1000. The prevalence is as high as 1% to 1.5% in inner-city populations. Approximately 30% of the exposed fetuses will also acquire the infection.

3. How Can HIV/AIDS Affect Pregnancy? In most cases, HIV will not cross through the placenta from mother to baby. If the mother is healthy in other aspects, the placenta helps provide protection for the developing infant. Factors that could reduce the protective ability of the placenta include in-uterine infections, a recent HIV infection, advanced HIV infection or malnutrition.

4. What Are The Chances That A Baby Will Become HIV Positive? A baby can become infected with HIV in the womb, during delivery or while breastfeeding. If the mother does not receive treatment, 25 percent of babies born to women with HIV will be infected by the virus.

5. Reducing Risk Of Transmission A multi-care approach is the most effective way for pregnant women with HIV infection to have a healthy pregnancy and delivery. The United States Public Health Service recommends that HIV-infected pregnant women be offered a combination treatment with HIV-fighting drugs to help protect her health and to help prevent the infection from passing to the unborn baby.

6. Reducing Risk Of Transmission Zidovudine was the first drug licensed to treat HIV. Now it is used in combination with other anti-HIV drugs and is often used to prevent perinatal transmission of HIV. ZDV should be given to HIV-infected women beginning in the second trimester and continuing throughout pregnancy, labor and delivery. Side effects include nausea, vomiting and low red or white blood cell counts.

7. Reducing Risk Of Transmission Zidovudine is associated with a decrease in perinatal HIV transmission to 8.3%. When care includes both zidovudine therapy and a scheduled cesarean delivery, the risk is approximately 2%. Nursing should be discouraged because the virus is secreted in breast milk.

8. During Delivery The chance of transmission is even greater if the baby is exposed to HIV- infected blood or fluids. Health care providers should avoid performing amniotomies, episiotomies and other procedures that expose the baby to the mother’s blood. The risk of transmission increases by 2% for every hour after membranes have been ruptured.

9. During Delivery Cesarean sections performed before labor and/or the rupture of membranes may significantly reduce the risk of perinatal transmission of HIV. Women who have not received any drug treatment before labor should be treated during labor with one of several possible drug regimens. These may include a combination of ZDV and another drug called 3TC or Nevirapine. Studies suggest that these treatments, even for short durations, may help reduce the risk to the baby.

10. Post Delivery The baby should be treated with ZDV for the first six weeks of life. Eight percent of babies of women treated with ZDV became infected, compared with 25 percent of babies of untreated women. No significant side effects of the drug have been observed other than a mild anemia in some infants that cleared up when the drug was stopped. Follow-up studies show that the HIV-negative treated babies continued to develop normally.