INFLUENCE OF OTHER MATERNAL VARIABLES ON THE RELATIONSHIP BETWEEN MATERNAL VIRUS LOAD AND MOTHER-TO-INFANT TRANSMISSION OF HUMAN-IMMUNODEFICIENCY-VIRUS TYPE-1

To assess the relationship between maternal human immunodeficiency vir us (HIV) type 1 RNA level, other important covariates, and mother-to-i nfant (vertical) transmission of HIV-1, third trimester repository spe cimens from 160 HIV-1-seropositive women enrolled in the Mothers and I nfants Cohort Study between 1986 and 1991 were assayed in batch for HI V-1 RNA. A significant association between peripheral blood HIV-1 RNA level and vertical transmission remained after controlling far CD4 cel l level, duration of ruptured membranes, ''hard'' drug (cocaine and he roin) use, and frequency of sexual activity during pregnancy, However, the association was attenuated among women with advanced HIV infectio n and those with a high frequency of sexual activity during pregnancy. In these settings, interventions that target risk factors other than virus load may be particularly important for preventing vertical trans mission of HIV-1.