Low-level prenatal lead exposure and infant sensory function

Table 1 Distribution of prenatal lead concentrations in the study sample at three time points (μg/dL)

	Infants with Newborn ABR Data							Infants with 6-Wk Grating VA Data
Lead exposure	N	GM (SD)^a	Percentile					N	GM (SD)^a	Percentile
			50th	75th	90th	95th	Max.			50th	75th	90th	95th	Max.
Mid-pregnancy^b	343	2.4 (2.5)	2.9	4.4	5.5	6.4	9.0	1038	2.4 (2.6)	2.9	4.4	6.3	8.2	19.0
Late-pregnancy^c	362	2.7 (2.3)	3.0	4.5	6.2	7.2	76.0	1058	2.9 (2.2)	3.3	4.7	6.4	7.7	69.8
Cord^d	321	<LOQ	<LOQ	3.2	5.0	5.7	24.7	949	<LOQ	2.1	3.3	4.7	5.5	13.5

^a GM geometric mean, SD standard deviation
^bMean (SD) gestational age at mid-pregnancy visit is 15.7 (2.2) weeks for ABR subset and 15.5 (1.9) weeks for VA data
^cMean (SD) gestational age at late-pregnancy visit is 38.8 (1.3) weeks for ABR subset and 39.3 (1.3) weeks for VA data
^dMean (SD) gestational age at birth is 39.2 (1.1) weeks for ABR subset and 39.7 (1.1) weeks for VA data

ISSN: 1476-069X