Table 3.

Difference in child nonverbal IQ score at 6 years of age per ${\log }_{10}$ increase in creatinine-adjusted maternal urine phthalate metabolite and bisphenol concentrations (measured in micrograms per gram creatinine), by timing of urine sampling.

Phthalate metabolitea and bisphenol concentrations	Unadjusted		Adjustedb		Mutually adjustedc
	B	95% CI	B	95% CI	B	95% CI
$\mathrm{\Sigma }$ LMWP metabolites
$<18\text{\hspace{0.17em}wks}$ of gestation	$-3.21$	$-4.64$, $-1.78$	$-1.68$	$-3.05$, $-0.32$	$-1.75$	$-3.21$, $-0.29$
18–25 wks of gestation	$-1.70$	$-3.30$, $-0.11$	0.27	$-1.25$, 1.79	1.04	$-0.58$, 2.67
$>25\text{\hspace{0.17em}wks}$ of gestation	$-2.85$	$-4.52$, $-1.18$	$-1.07$	$-2.65$, 0.51	$-0.80$	$-2.50$, 0.90
Averaged	$-4.85$	$-6.96$, $-2.75$	$-1.68$	$-3.72$, 0.36	—
$p$-Valued						0.06
$\mathrm{\Sigma }$ HMWP metabolites
$<18\text{\hspace{0.17em}wks}$ of gestation	$-3.63$	$-5.55$, $-1.70$	$-1.80$	$-3.62$, 0.03	$-1.98$	$-3.82$, $-0.13$
18–25 wks of gestatione	$-0.87$	$-2.81$, 1.07	1.04	$-0.80$, 2.87	1.19	$-0.67$, 3.05
$>25\text{\hspace{0.17em}wks}$ of gestatione	$-0.14$	$-2.82$, 2.54	0.73	$-1.79$, 3.26	0.79	$-1.76$, 3.33
Averaged	$-4.41$	$-7.69$, $-1.12$	$-0.37$	$-3.52$, 2.78	—
$p$-Valued						0.09
$\mathrm{\Sigma }$ DEHP metabolites
$<18\text{\hspace{0.17em}wks}$ of gestation	$-3.20$	$-5.09$, $-1.31$	$-1.73$	$-3.52$, 0.05	$-1.89$	$-3.69$, $-0.09$
18–25 wks of gestation	$-0.42$	$-2.33$, 1.49	0.92	$-0.88$, 2.72	1.06	$-0.76$, 2.88
$>25\text{\hspace{0.17em}wks}$ of gestation	0.20	$-2.38$, 2.77	0.65	$-1.78$, 3.09	0.71	$-1.75$, 3.16
Averaged	$-2.21$	$-4.64$, 0.22	0.05	$-2.26$, 2.36	—
$p$-Valued						0.11
$\mathrm{\Sigma }$ DNOP metabolites
$<18\text{\hspace{0.17em}wks}$ of gestation	$-2.61$	$-4.46$, $-0.76$	$-1.98$	$-3.72$, $-0.23$	$-1.86$	$-3.65$, $-0.08$
18–25 wks of gestation	$-0.13$	$-2.20$, 1.94	0.38	$-1.57$, 2.32	0.87	$-1.1$, 2.84
$>25\text{\hspace{0.17em}wks}$ of gestation	$-1.10$	$-3.64$, 1.43	$-2.39$	$-4.76$, $-0.02$	$-2.10$	$-4.51$, 0.30
Averaged	$-3.28$	$-6.47$, $-0.09$	$-2.97$	$-6.00$, 0.06	—
$p$-Valued						0.03
PA metabolites
$<18\text{\hspace{0.17em}wks}$ of gestation	$-2.59$	$-4.32$, $-0.87$	$-1.93$	$-3.55$, $-0.31$	$-1.90$	$-3.55$, $-0.25$
18–25 wks of gestation	$-0.90$	$-2.72$, 0.91	0.85	$-0.87$, 2.57	1.07	$-0.66$, 2.80
$>25\text{\hspace{0.17em}wks}$ of gestation	$-2.46$	$-4.75$, $-0.17$	$-1.09$	$-3.25$, 1.07	$-0.78$	$-2.98$, 1.42
Averaged	$-4.64$	$-7.57$, $-1.71$	$-1.77$	$-4.57$, 1.04	—
$p$-Valued						0.05
Bisphenol metabolites
$<18\text{\hspace{0.17em}wks}$ of gestationf	0.38	$-1.10$, 1.86	0.49	$-0.90$, 1.87	0.48	$-0.90$, 1.87
18–25 wks of gestationg	0.48	$-1.19$, 2.15	0.13	$-1.44$, 1.70	0.12	$-1.44$, 1.69
$>25\text{\hspace{0.17em}wks}$ of gestationh	1.05	$-0.74$, 2.85	0.05	$-1.62$, 1.72	0.06	$-1.61$, 1.74
Averaged	1.81	$-1.03$, 4.65	0.76	$-1.89$, 3.42	—
$p$-Valued						0.92

Note: —, not applicable; B, unstandardized beta; BMI, body mass index; CI, confidence interval; DEHP, di-2-ethylhexylphthalate; DNOP, di-$n$-octylphthalate; HMWP, high-molecular weight phthalate; IQ, intelligence quotient; LMWP, low-molecular weight phthalate; PA, phthalic acid.

^aPhthalate metabolites are grouped into the following categories: LMWP metabolites (sum of mono-methyl phthalate, mono-ethyl phthalate, mono-isobutyl phthalate, mono-$n$-butyl phthalate); HMWP metabolites [sum of mono-(2-ethyl-5-carboxypentyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, mono-[(2-carboxymethyl)hexyl] phthalate, mono(3-carboxypropyl) phthalate, monobenzyl phthalate, mono-hexyl phthalate, and mono-2-heptyl phthalate]; DEHP metabolites: [sum of mono (2-ethyl-5 carboxypentyl) phthalate, mono (2-ethyl-5 hydroxyhexyl) phthalate, mono-(2-ethyl-5-oxohexyl) phthalate, and mono-[(2-carboxymethyl)hexyl] phthalate]; DNOP metabolites [mono(3-carboxypropyl) phthalate]; and PA (a proxy for total phthalate exposure).

^bAdjusted for maternal age, maternal nonverbal IQ, sex of child, age of the child at assessment, ethnicity, education, income, marital status, maternal alcohol consumption, BMI, parity categories, and smoking.

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

^dTests whether exposure from different time points relates in the same manner to nonverbal IQ scores using the multiple informant method (Sánchez et al. 2011).

^eWith the exclusion of mono-hexyl phthalate and mono-2-heptyl phthalate metabolite concentrations.

^fTotal bisphenol: sum of bisphenol A, bisphenol F, and bisphenol S.

^gTotal bisphenol: sum of bisphenol A and bisphenol S.

^hTotal bisphenol: sum of bisphenol A and bisphenol F.