Neurobehavioral deficits after low level lead exposure in neonates: the Mexico City pilot study.

Gestation age and ability of the baby to self-quiet and to be consoled during the first 30 days of life decrease when mother's blood lead levels rise from 36 weeks of pregnancy to birth of child. These effects appear to be independent of the absolute lead levels of mother and child (N = 42). Since pre- and perinatal stress predicts higher maternal birth lead, further work could determine the relative contributions of undetected stress during pregnancy and elevated lead levels upon subsequent development. Several cases, not included in the statistical analyses, showed associations between cord leads greatly elevated over maternal leads and poor outcome.