Critical Issues in Treating HIV During Pregnancy.
When the AIDS Clinical Trial Group (ACTG) broke the code for Protocol 076, researchers discovered that giving zidovudine (formerly called azidothymidine, or AZT) to HIV-infected women during pregnancy (100mg PO 5 times daily) and labor (2mg/kg of body weight IV, given over 1 hour, then 1mg/kg/hr until delivery), plus to the newborn (2mg/kg PO q6h for 6 weeks), could cut perinatal HIV transmission by two thirds. Now, further studies are also adding to the databank of information about HIV in pregnancy. For example, one study has shown that pregnancy does not hasten the progression of HIV; another has indicated that although vertical HIV transmission often occurs late in gestation, it also can occur as early as 8 weeks. One group of researchers discovered that zidovudine is highly effective in blocking viral transmission, but when the mother develops resistance, she is likely to pass the resistant viral strain to the fetus. The importance of measuring viral load has been suggested by research demonstrating that the number of HIV RNA copies can help predict which women are most likely to transmit the virus to the fetus. In one study, among women with more than 80,000 RNA copies/mL, everybody transmitted the virus; with less than 20,000 copies, nobody transmitted. Of great interest is that the 22 women in this study who took zidovudine showed an 8-fold median decrease in the plasma RNA levels.
Landsberger
EJ
High-Risk Obstetrics Clinic at The New York Hospital-Cornell Medical Center, New York City, NY.