PRENATAL AND PERINATAL LEAD EXPOSURES ALTER ACOUSTIC CRY PARAMETERS OF NEONATE

We performed acoustic analyses on cries elicited from a subset of heal thy babies born to the Mexico City Prospective Lead Study at 2 days (n = 75), 15 days (n = 176), and 30 days (n = 166). Lead was measured in maternal blood every 8 weeks during pregnancy from week 12 to deliver y and in umbilical cord (1-38 mu g/dL, 0.05-1.84 mu mol/L). Percent na salization and number of cries decreased in babies born to mothers wit h higher lead levels in the last two trimesters while median fundament al frequency increased in babies born to mothers with higher lead at 1 2 weeks of pregnancy, and with higher cord lead in multiple regression analysis. Decreased percent nasalization was related to increased bra instem auditory evoked response latencies and interpeak intervals in a subset of the sample. The results suggest an effect of gestational ex posure to lead on apparatus innervated by cranial nerves and/or lead e ffect on cry mediated by lead-altered auditory function. Altered baby cry and auditory function associated with lead might contribute to dev elopmental delays by affecting early communication between caretaker a nd baby.