Table 4.

Regression coefficients and 95% confidence intervals for Hg level associated with birth weight according to GSTM1/GSTT1 genotype.

Exposure period of total Hg (log scale of μg/L)	Genotype			Adjusteda
		Unadjusted		Full sample		Subsample excluding preterm births
		β	95% CI	β	95% CI	β	95% CI
Early pregnancy	Total	−4.4	−79.5 to 70.8	−68.6	−138.6 to 1.5	−51.4	−122.2 to 19.5
	GSTM1 present	66.8	−55.6 to 189.2	−37.5	−154.6 to 79.7	−37.8	−155.4 to 79.8
	GSTM1 null	−48.3	−143.9 to 7.3	−79.5	−168.9 to 9.9	−47.9	−138.8 to 43.0
	GSTT1 present	9.1	−109.7 to 128.0	−50.7	−158.7 to 57.3	−24.0	−137.8 to 89.9
	GSTT1 null	−13.7	−110.2 to 82.7	−70.2	−166.5 to 26.0	−63.8	−157.9 to 30.3
Late pregnancy	Total	−27.1	−103.1 to 49.0	−65.5	−135.6 to 4.5	−40.1	−110.9 to 30.0
	GSTM1 present	39.2	−89.1 to 167.5	−34.3	−153.7 to 85.1	−22.7	−144.6 to 99.3
	GSTM1 null	−64.4	−159.3 to 30.4	−84.8	−171.4 to 1.7	−57.3	−143.8 to 29.3
	GSTT1 present	3.3	−124.6 to 131.1	−25.6	−140.4 to 89.2	−5.7	−122.4 to 111.0
	GSTT1 null	−49.1	−142.1 to 44.0	−99.0	−189.2 to −8.8	−66.8	−156.7 to 23.1
Cord blood	Total	−33.0	−116.1 to 49.9	−86.4	−163.1 to −9.7	−65.2	−143.0 to 12.5
	GSTM1 Present	54.9	−88.9 to 198.6	−68.3	−206.6 to 70.1	−59.6	−199.5 to 80.3
	GSTM1 null	−78.5	−180.5 to 23.5	−107.3	−199.7 to −14.8	−74.7	−168.5 to 19.2
	GSTT1 Present	−39.5	−162.2 to 83.1	−77.7	−187.6 to 32.3	−54.9	−168.2 to 58.4
	GSTT1 null	−30.5	−144.3 to 83.4	−101.0	−212.3 to 10.4	−76.5	−187.6 to 34.6

^aMultivariate regression models included gestational age, prepregnancy BMI, maternal age, mother’s educational level, infant sex, parity, and weight gain during pregnancy as covariates.