Table 2.

Difference in cognitive test score at 6 y of age (and 95% confidence interval) per ${\log }_{10}$ nanomoles per gram creatinine increase in maternal urine dialkylphosphate metabolite concentration, by timing of pregnancy urine sampling and degree of adjustment ($n=708$).

Dialkylphosphate type	Not adjusted		Adjusteda		Mutually adjustedb
	$\mathrm{\beta }$	(95% CI)	$\mathrm{\beta }$	(95% CI)	$\mathrm{\beta }$	(95% CI)
Dialkylphosphates (total)c
$<18\text{\hspace{0.17em} weeks}$ of gestation	$-0.7$	$-4.1$, 2.8	$-1.9$	$-5.3$, 1.5	$-1.8$	$-5.3$, 1.6
18–25 weeks of gestation	3.2	$-0.6$, 7.0	0.9	$-2.9$, 4.7	2.6	$-1.4$, 6.6
$>25\text{\hspace{0.17em} weeks}$ of gestation	$-0.8$	$-4.4$, 2.8	$-3.9$	$-7.5$, $-0.3$	$-4.3$	$-8.1$, $-0.6$
Mean of three urines	0.6	$-4.3$, 5.5	$-2.5$	$-7.4$, 2.4		—
p Homogeneityd						0.051
Diethyl alkyl phosphatese
$<18\text{\hspace{0.17em} weeks}$ of gestation	0.1	$-2.4$, 2.6	$-1.4$	$-3.8$, 1.1	$-1.5$	$-4.0$, 1.0
18–25 weeks of gestation	2.1	$-0.4$, 4.7	0.6	$-1.9$, 3.1	0.9	$-1.7$, 3.5
$>25\text{\hspace{0.17em} weeks}$ of gestation	2.2	$-0.3$, 4.7	$-0.2$	$-2.8$, 2.3	$-0.3$	$-2.9$, 2.3
Mean of three urines	4.4	0.6, 8.2	1.0	$-2.8$, 4.9		—
p Homogeneityd						0.475
Dimethyl alkyl phosphatesf
$<18\text{\hspace{0.17em} weeks}$ of gestation	$-1.6$	$-4.9$, 1.7	$-2.5$	$-5.7$, 0.7	$-2.3$	$-5.6$, 0.9
18–25 weeks of gestation	2.6	$-1.0$, 6.3	0.7	$-3.0$, 4.3	2.3	$-1.4$, 6.1
$>25\text{\hspace{0.17em} weeks}$ of gestation	$-1.6$	$-5.0$, 1.9	$-4.1$	$-7.5$, $-0.7$	$-4.3$	$-7.9$, $-0.8$
Mean of three urines	$-0.6$	$-5.4$, 4.1	$-3.0$	$-7.7$, 1.7		—
p Homogeneityd						0.030

Note: BMI, body mass index; CI, confidence interval; DEDTP, diethyldithiophosphate; DEP, diethylphosphate; DETP, diethylthiophosphate; DMDTP, dimethyldithiophosphate; DMP, dimethylphosphate; DMTP, dimethylthiophosphate; IT-HOME, Infant/Toddler Home Observation for Measurement of the Environment inventory; —, not applicable.

^aAdjusted for age of the mother, sex of child, ethnicity categories (Dutch, other-Western, and non-Western), education (low, intermediate, and high), income (low, middle, and high), marital status, maternal alcohol consumption (no alcohol consumption during pregnancy, alcohol consumption until pregnancy was known, occasional alcohol consumption during pregnancy, and frequent alcohol consumption during pregnancy), maternal nonverbal IQ, BMI categories ($<18.5$, 18.5–25, 25–30, $>30{\mathrm{kg}/\mathrm{m}}^2$), height of the mother, parity categories (0, 1, $\ge 2$), IT-HOME quartiles, and smoking categories (no smoking during pregnancy, smoked until pregnancy was known, smoked during pregnancy).

^bAdjusted model with the inclusion of the three exposures in one model.

^cTotal dialkylphosphates is the sum of DEDTP, DETP, DEP, DMDTP, DMTP, and DMP.

^dMultiple-partial F-test used to test whether exposure from different time points relates in the same manner to nonverbal IQ scores.

^eDiethyl alkyl phosphates is the sum of DEDTP, DETP, and DEP.

^fDimethyl alkyl phosphates is the sum of DMDTP, DMTP, and DMP.