Table 1.

Descriptive maternal characteristics (N=187) and for the subset with all three urine samples available (N=20)

		Full (N=187)			Sub-set (N=20)
Characteristics		N (%)		Median (25th, 75th)	N (%)		Median (25th, 75th)	p*
Maternal Age			187	26 (22, 30)		20	28(23, 31)	0.59
Maternal Education			187	11 (9, 11)		20	12(9,12)	0.71
Maternal IQ			187	96 (88, 103)		20	96(89, 107)	0.72
Socioeconomic Status			178	8.0 (6.0, 11)		18	7.5(6.0, 10.0)	0.98
Blood Lead (ug/dl)			187	5.4(3.3, 7.8)		20	5.9(2.6, 7.7)	0.51
Marital Status								0.71
Married		139(74)			16(80)
Divorced		1(0.5)				0
Separated		1(0.5)			1(5)
Never married		15(8)			2(15)
Living with partner		31(17)				0
Smoking during Pregnancy
Some days		2(1)			1(10)			0.8
Not at all		185(99)			9(90)
Season of Sample Collection
rainy- June to October		89 (48)			5 (25)			0.04
dry - November to May		98 (52)			15(75)
Breastfed
Yes		167(90)			18(90)			0.98
No		19(10)			2(10)
Trimester of Pregnancy
1st Trimester		10(5)			10(5)
2nd Trimester		11(6)			11(6)
3rd Trimester		187(100)			187(100)

^*Two sample t-test