HIV infection in pregnant women has been shown to have an adverse effect on the fetus and newborn. We undertook this study to examine the adverse effect of maternal HIV-1 infection on two outcomes of the previous pregnancy, as reported by the women: childhood mortality under the age of 3 years and spontaneous abortion. Some 6605 consecutive women who presented to a large urban hospital in Malawi for antenatal care were interviewed and tested for HIV-1 antibody. Of these 4229 (64%) were multiparous and 833 (19.7%) were seropositive for HIV-1. A history of under-3 mortality of the previous pregnancy was more common in HIV-1 seropositive than HIV-1 seronegative women (35% versus 15%, P less than 0.001). In the previous pregnancy, death of infants and children under 3 years was 77 and 119 per 1000 respectively for HIV-1 seronegative mothers, but increased to 171 and 292 per 1000 in infants and children under 3 years for HIV-1 seropositive mothers. History of child mortality was independently associated with positive HIV-1 serology, positive syphilis serology, low socioeconomic status, young age and not having married. There was no correlation between history of child mortality and reported symptoms of HIV/AIDS by infected mothers, except for history of tuberculosis which was reported more often by mothers whose child had died (4% versus 1%, P less than 0.036).(ABSTRACT TRUNCATED AT 250 WORDS)