HIV infection in women and children is a special problem in Zaire and in other countries where heterosexual transmission is predominant. Nearly half of the cases of HIV infection are in women 15 to 30 years old and as many as seven infected infants may be born each year. Whether or not infected at birth, these children have mothers, and often fathers, who are infected and likely to die while they are still very young. Such orphaned children, as well as those whose families cannot provide adequate food and health care, add to the problematic economies of developing countries. The problems of children of HIV-infected mothers in developing countries may be compounded further by factors directly related to their mother's disease. Infected mothers who are sick may produce insufficient levels of antibodies and be unable to provide their children with adequate natural passive immunity before birth. Their infants may also receive inadequate levels of breast-milk-derived antibodies possibly enhancing their already increased susceptibility to perinatal infections, and lastly, the volume of breast milk produced by these mothers may be inadequate for the nutrition of these infants. All these factors may further compromise the already difficult task of distinguishing those infants of HIV-infected mothers who are ill because they are infected from those who are ill because of their mother's disease. Regardless of the mechanisms accounting for the increased vulnerability of infants of HIV--seropositive and AIDS-afflicted mothers to perinatal infections, infant mortality can be expected to increase significantly as a direct consequence of the progression of the HIV pandemic throughout Africa and possibly other developing countries; this in populations already with a total under five-years-of-age mortality rate exceeding 15%. The association of chorioamnionitis with HIV seropositivity and with the clinical status of the mother seems to suggest that impaired maternal immunity increases the risk of premature birth, its consequent lower birth weight, and to HIV or other perinatally acquired infections. The identification of women at higher risk of chorioamnionitis and their treatment might provide a means to decrease the risk of premature delivery and possibly reduce the rate of HIV transmission to their infants. The pathologic changes in organs of infants and children with HIV infection require in-depth, systematic study to better define the natural history of perinatal HIV disease and infection.(ABSTRACT TRUNCATED AT 400 WORDS)