Prevention of maternal HIV transmission. Practical guidelines.

The recently published Protocol 076 study (ACTG 076/ANRS 024) showed that zidovudine significantly decreased the relative risk of maternal HIV transmission by 71.5% compared with placebo. Oral zidovudine 100 mg five times daily until the onset of labour, followed by intravenous zidovudine 2 mg/kg over 1 hour then 1 mg/kg.h until delivery, or an identical placebo regimen were administered to HIV-infected pregnant women (14 to 34 weeks' gestation) with CD4+ counts > 200 cells/microliters. 400 babies born to these women received zidovudine syrup 2 mg/kg or placebo administered 6-hourly for 6 weeks. The zidovudine regimens were well tolerated by both mothers and infants. Further studies should aim to determine the mechanism by which zidovudine reduces the risk of maternal HIV transmission, the timing of HIV transmission, the efficacy of zidovudine in women not meeting the entry criteria for Protocol 076 and the long term effects of zidovudine during pregnancy on both mother and infant, and should examine the possibility of developing a simplified zidovudine regimen. Following recent guidelines from the US and French public health services, the full Protocol 076 regimen should be given to all women fulfilling that study's entry criteria. This regimen should also be considered in women with more severe disease or in later stages of gestation. Clinical efficacy of zidovudine should be monitored closely in women and infants, who should also be followed up for long term adverse effects. Unblinded screening for HIV in pregnant women in the USA is facing extreme opposition; nevertheless, guidelines on HIV counselling and HIV testing of pregnant women are currently being developed there in light of the Protocol 076 findings.