Table 3.

Weighted quantile sum (WQS) index for metals mixtures (using decile score) during second and third trimesters, related to birth weight Z-score. Bolded values highlight all P-values <0.05.

		Model 1				Model 2
		Positive Direction*		Negative Direction*		Positive Direction*		Negative Direction*
		Second trimester	Third trimester	Second trimester	Third trimester	Second trimester	Third trimester	Second trimester	Third trimester
Beta		0.075	0.067	−0.03	−0.003	0.116	0.134	−0.09	−0.025
SE		0.038	0.039	0.04	0.04	0.069	0.073	0.06	0.067
P-value		0.047	0.085	0.348	0.946	0.094	0.065	0.148	0.711
Metal		Weights	Weights	Weights	Weights	Weights	Weights	Weights	Weights
	Mn	0.75	0.83	0.01	0.05	0.93	0.84	0.00	0.02
	Pb	0.02	0.07	0.98	0.85	0.00	0.03	0.98	0.93
	Zn	0.23	0.10	0.01	0.10	0.07	0.13	0.01	0.05

^*Positive direction indicates the association of metals with birth weight Z-score constrained to be positive; Negative direction indicates the association of metals with birth weight Z-score constrained to be negative

SE, standard error; Mn, manganese; Pb, lead; Zn, Zinc

Model 1: Adjusted for batch, tooth attrition, tooth type, and race

Model 2: Adjusted for batch, tooth attrition, tooth type, race, urban, ETS, anemic, maternal age, and year house built