Lead levels in human placentae from normal and malformed births.

Placental lead levels were studied in a series of Birmingham births classified by stillbirth, neonatal death, or survival beyond one week. There was an appreciable range of lead levels even in normal births (0.15-3.56 microgram/g) but nevertheless average results showed a pronounced excess of lead in those who failed to survive both birth and the neonatal period. There was no association of placental lead with impaired birthweight among survivors but, in common with other authors, we noted a seasonal variation. The placentae from Indian women had similar lead levels to those from European women and lower values were found in the normal sibs of stillbirths and neonatal deaths. The possibility is discussed that under conditions of impaired fetal health in late pregnancy the placenta may concentrate lead.