Recommendations of the U.S. Public Health Service Task Force on the Use of Zidovudine to Reduce Perinatal Transmission of Human Immuno deficiency Virus

Vol. 43 / No. RR-11

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BOX 1. Eligibility criteria for HIV-infected pregnant women participating in AIDS
Clinical Trials Group Protocol 076
* Pregnancy at 14-34 weeks of gestation.
* No antiretroviral therapy during the current pregnancy.
* No clinical indications for antenatal antiretroviral therapy.
* CD4+ T-lymphocyte count 200 cells/gL at the time of entry into the study.
BOX 2. Zidovudine regimen from AIDS Clinical Trials Group Protocol 076
* Oral administration of 100 mg of zidovudine (ZDV) five times daily, initiated at
14-34 weeks of gestation and continued throughout the pregnancy.
* During labor, intravenous administration of ZDV in a 1-hour loading dose of 2
mg per kg of body weight, followed by a continuous infusion of 1 mg per kg of
body weight per hour until delivery.
* Oral administration of ZDV to the newborn (ZDV syrup at 2 mg per kg of body
weight per dose every 6 hours) for the first 6 weeks of life, beginning 8-12 hours
after birth.
from all infants at birth and at 12, 24, and 78 weeks of age. A positive viral culture was
considered indicative of HIV infection. Sera from the infants at 15 and 18 months of
age also were tested for HIV antibody.
The Kaplan-Meier method (7) was used to estimate the rate of perinatal transmission at 18 months of age among the 364 children whose HIV infection status was
known on the basis of culture and who therefore were included in the interim analysis.
The estimated transmission rate was 25.5% among the 184 children in the placebo
group (95% confidence interval [CI]=18.4%-32.5%), compared with 8.3% among the
180 children in the ZDV group (95% CI=3.9%-12.8%). The difference in the estimated
transmission rate between the two groups was statistically significant (p=0.00006).
ZDV treatment did not appear to delay the diagnosis of HIV infection.
Observed toxicity specifically attributable to ZDV was minimal among the women
in this study. Adverse effects such as anemia, neutropenia, thrombocytopenia, and
liver chemistry abnormalities were reported as frequently among women receiving
placebo as among women receiving ZDV. Six women-three in each treatment
group-discontinued therapy because of toxicity attributed to the study drug. The
women were evaluated at 6 weeks and 6 months postpartum. A statistically significant
increase in CD4+ T-lymphocyte count from baseline to 6 weeks postpartum was
observed for women in both ZDV and placebo treatment groups; this increase was
greater among women in the ZDV group. At 6 months postpartum, the CD4+
T-lymphocyte counts for both groups had decreased to similar levels. CD4+
T-lymphocyte counts decreased to <200/tL in only four women, including one receiving ZDV and three receiving placebo. No women died during the study.