Reflections on the occurrence and significance of antepartum fetal asphyxia.

This chapter documents the growing evidence of the occurrence and significance of antepartum fetal asphyxia. Perinatal mortality studies demonstrate that the majority of fetal deaths, including those due to asphyxia, occur in the antepartum period. Epidemiological studies of cerebral palsy conclude that a minority of cases of cerebral palsy are due to intrapartum fetal asphyxia and implicate antenatal events, including asphyxia. Cordocentesis studies have confirmed that antepartum fetal asphyxia occurs in the growth-restricted fetus and might contribute to the increase of stillbirths and cerebral palsy in these children. Blood gas and acid-base studies in the immature fetus have demonstrated the increased prevalence of fetal asphyxia, and particularly of moderate or severe asphyxia, of which the majority might occur in the antepartum period. The ultimate determination of the prevalence and significance of antepartum fetal asphyxia requires the development of a non-invasive specific measure of fetal asphyxia.