Antiretroviral Drugs Do Not Increase Pregnant Woman’s Risk of Premature Delivery or Delivery of Low Birthweight Infant, Study States
HIV-positive pregnant women who take antiretroviral drugs are at no greater risk for premature delivery or delivery of a low birthweight infant than HIV-positive pregnant women who do not take antiretroviral medicines, according to a study in today's issue of the New England Journal of Medicine, the New York Times reports. The study was started by the NIH after previous research had indicated that antiretroviral medicines may pose a risk during pregnancy (Stolberg, New York Times, 6/13). Researchers evaluated 3,266 HIV-positive pregnant women who were enrolled in clinical studies and delivered their infants between 1990 and 1998 to determine whether antiretroviral treatment had an effect on the risk of certain pregnancy-related adverse events, including premature delivery, low birthweight and stillbirth. Of the participants, 1,143 did not receive antiretroviral treatment and 2,123 received some form of antiretroviral treatment. Of the women who received treatment, 1,590 received monotherapy, 396 received combination therapy without protease inhibitors and 137 received combination therapy with protease inhibitors. A summary of the study's findings follow:
- All participants, regardless of therapy, had similar rates of premature delivery, low birthweight, very low birthweight and stillbirth.
- After adjustment for several risk factors, combination antiretroviral therapy was not associated with an increased risk of premature delivery or delivery of a low birthweight infant when compared with monotherapy.
- Five percent of women who received therapy with a protease inhibitor delivered very low birthweight infants, compared to 2% of women who received combination treatment without a protease inhibitor.
HIV Infection Management Guidelines
A second article appearing in the New England Journal of Medicine presents guidelines for the management of HIV infection in pregnant women in developed countries where such services as antiretroviral therapy, scheduled caesarean delivery and alternatives to breastfeeding are available. A summary of the guidelines appears below:
- Antepartum care: Physicians should determine a woman's symptoms, the duration of her HIV infection and any immunizations she has received. A woman should receive an ophthalmologic exam if her CD4+ T-cell count is less than 50 cells per cubic millimeter, and patients should also be screened for tuberculosis, cytomegalovirus, hepatitis C and liver function. Women should receive counseling on the effect of pregnancy on HIV infection, the risk of vertical HIV transmission and the effects of antiretroviral treatment and mode of delivery on the risk of vertical transmission.
- Antiretroviral therapy during pregnancy: All HIV-positive pregnant women should be offered antiretroviral therapy, the article states. Pregnant women with viral loads below 1,000 copies per milliliter should be considered candidates for zidovudine monotherapy or highly active antiretroviral therapy. Guidelines issued by the Public Health Service state that pregnant women should be tested for drug resistance in the same manner as non-pregnant adults. Antiretroviral therapy depends on the gestational age of the fetus -- an HIV-positive woman who has been undergoing antiretroviral treatment and whose pregnancy is discovered after the first trimester should continue treatment, and the fetus should be screened for anomalies. For pregnancies detected within the first trimester, decisions regarding drug regimens should depend on the clinical circumstances and treatment history.
- Mode of delivery: Early studies have suggested that caesarean delivery before the onset of labor or before membranes have ruptured is effective in reducing the rate of vertical transmission among women who have not received antiretroviral therapy. However, the decision must be weighed with certain risks because c-section delivery carries higher risks of complications and death. Current guidelines recommend that scheduled caesarean section delivery be offered to women with HIV viral levels above 1,000 copies per milliliter in the late stages of pregnancy and that the benefits and risks of c-sections be discussed thoroughly. Infusion of zidovudine should be started as soon as possible after the onset of labor or the rupture of the membranes or at least three hours prior to a scheduled c-section, the article states.
- Postpartum treatment for infants: The optimal treatment for infants born to HIV-positive women who have received no antiretroviral treatment has not yet been determined. Some data recommend zidovudine therapy initiated within 48 hours after birth, while some clinicians say that a combination regimen similar to that used for post-exposure prophylaxis treatment in adults is beneficial.
- Postpartum care: Doctors should check to ensure that women who continue antiretroviral therapy after delivery adhere to their drug regimens. New mothers need psychosocial support while the infant's HIV status is being determined. It is not recommended that HIV-positive women breastfeed their infants because this can increase the risk of HIV transmission. Doctors should also discuss future contraceptive choices with women and emphasize the need for condom use. Physicians should also tell women about the possibility of drug interactions between hormonal contraceptives and antiretroviral drugs that could reduce contraceptive efficacy (Watts, New England Journal of Medicine, 6/13).