Safety and efficacy of lamivudine + zidovudine during pregnancy has not yet been evaluated. In a nationwide controlled non-randomized study lamivudine was given at 150mg BID from 32 weeks until labor, and to the neonate at 2mg/kg BID until 6 weeks. Zidovudine was given according to the 076 regimen. The study was integrated in the prospective French cohort, and outcomes were compared with those following zidovudine monotherapy. 440 women were enrolled. Present analysis concerns the first 200 mother-infant pairs, with > 6 mths follow-up of the child, which were compared with 899 pairs in the cohort receiving zidovudine monotherapy. Maternal tolerance was satisfactory despite slight differences in serum transaminase, creatinine and neutrophil. In neonates, biologic parameters did not differ from the control group. Maternal plasma HIV RNA decreased under combo by 0.95Log. The mother-to-child transmission rate was 2.6% (5/194), vs. 6.5% (53/810) with zidovudine monotherapy p<0.04. M184V mutation was detected at 6 weeks post-partum in 52 of 132 women. Factors related to the acquisition of the mutation were pre-treatment HIV RNAl, CD4 and duration of treatment with lamivudine. None of the 11 women treated less than 4 weeks developed a detectable M184V mutation p<0.001. A short course of lamivudine and zidovudine in the third trimester appeared safe and more effective than zidovudine alone for the prevention of mother-to-child HIV-1 transmission. Risk of selection of the M184V mutation is high if treatment is maintained for more than one month.
Keywords: AEGIS, Lamivudine, Zidovudine, HIV-1, Anti-HIV Agents, Reverse Transcriptase Inhibitors, HIV-1 Reverse Transcriptase, Mothers, Mutation, Child, Human, Female, Infant, Pregnancy, transmission, prevention & control, genetics, AIDS
