The dramatic excess of low birthweight and infant deaths among black babies compared to whites cannot be completely explained by differences either in sociodemographic factors or in prenatal care patterns. It is suggested that part of the explanation resides in characteristics of the mothers' own intrauterine and childhood environment which interfere with their optimal growth and development and become manifest later in suboptimal reproductive outcome. Conditions in the adult environment under which pregnancies occur also appear to interfere with fetal development. This evidence points to the need for programs to care for children as they grow and develop and for women before and during their pregnancies. Research should be encouraged which may help to elucidate the biological mechanisms by which intrauterine, childhood and adult environments of one generation translate into health hazards for the next generation.