[Treatment failure of preventive zidovudine in maternal fetal transmission of HIV]. / Echec du traitement préventif de la transmission materno-foetale du VIH par la zidovudine (AZT).

The role of zidovudine therapy during pregnancy in women infected with HIV-1 is still controversial. A case of a 40-year-old woman, seropositive for HIV-1 since a blood transfusion in 1984 is reported. She was treated by zidovudine since 1989 because of a CDC stage IIIb. The treatment was continued throughout pregnancy at the dose of 600 mg per day. A cesarean section was performed in the 40th week of amenorrhoea. The newborn weighed 3940 g. Viral culture was negative at birth, but positive at the age of four months. Zidovudine and its glucuronide were measured by high performance liquid chromatography in maternal blood taken by venopuncture, in amniotic fluid and in cord blood. In our case, zidovudine was ineffective in preventing transmission of HIV to the fetus despite of a concentration in cord blood higher than minimal therapeutic concentration in vitro. It must be pointed out that all cases of lack of efficacy of zidovudine were described in patients with CD4-cell count lower than 250 per cubic millimeter.