Table 1.

Sociodemographic characteristics for children with measured prenatal urinary DAP metabolites who were followed up until the birth ($n=534$) and those with measured prenatal DAPs and 14-year SRS-2 T-scores ($n=247$), and medianT-scores across these characteristics in the CHAMACOS study population, enrolled 1999–2000 in Salinas Valley, California.

Characteristic	$n=534$ with DAPs	$n=247$ with DAPs and SRS-2a
	$n$ (%)	$n$ (%)	T-score Median (Q1, Q3)
Maternal/family factors
Maternal age at child delivery
18–24	263 (49.3)	111 (44.9)	55.0 (51.0, 59.0)
25–29	157 (29.4)	74 (30.0)	56.0 (48.0, 61.0)
30–34	78 (14.6)	42 (17.0)	55.0 (50.0, 58.0)
35–45	36 (6.7)	20 (8.1)	58.0 (51.0, 61.5)
Maternal country of birth
U.S.	70 (13.1)	30 (12.2)	53.0 (49.0, 59.0)
Mexico	452 (84.6)	214 (86.6)	55.0 (51.0, 60.0)
Other	12 (2.3)	3 (1.2)	56.0 (41.0, 69.0)
Maternal years in U.S. at child delivery
$\le 1$	129 (24.2)	51 (20.7)	55.0 (49.0, 60.0)
2–5	144 (27.0)	63 (25.5)	57.0 (51.0, 60.0)
6–10	116 (21.7)	70 (28.3)	57.0 (52.0, 61.0)
$11+$ (includes entire life)	145 (27.2)	63 (25.5)	53.0 (48.0, 58.0)
Maternal Language for 14 y questionnaire
Spanish	316 (87.3)	216 (87.5)	55.0 (51.0, 60.0)
English	46 (12.7)	31 (12.6)	52.0 (48.0, 58.0)
Missing	172
Maternal education at child delivery
$<6\text{th}\text{grade}$	233 (43.6)	106 (42.9)	56.0 (51.0, 61.0)
7–12th grade	192 (36.0)	90 (36.4)	55.5 (49.0, 60.0)
Completed high school	109 (20.4)	51 (20.7)	54.0 (48.0, 59.0)
Maternal marital status at child delivery
Not married to/living with child's father	102 (19.1)	42 (17.0)	56.5 (49.0, 61.0)
Married to/living with child's father	432 (80.9)	205 (83.0)	55.0 (50.0, 60.0)
Parity at child delivery
Nulliparous	184 (34.5)	78 (31.6)	55.0 (49.0, 59.0)
$1+$	350 (65.5)	169 (68.4)	55.0 (51.0, 60.0)
Maternal verbal intelligence (PPVT score) at 9-year visitb
$<74$	118 (25.5)	47 (19.1)	57.0 (51.0, 61.0)
75–99	154 (33.3)	86 (35.0)	55.0 (50.0, 60.0)
$100+$	190 (41.1)	113 (45.9)	55.0 (49.0, 59.0)
Missing	72	10
Maternal Depression ($\ge 16$ on CES-D) at 9-year visitb
No	308 (69.8)	177 (72.0)	54.0 (49.0, 59.0)
Yes	133 (30.2)	69 (28.1)	58.0 (54.0, 65.0)
Missing	93	1
Family poverty at $10½-\text{year}$ visitb
$<\text{Poverty}\text{level}$	246 (72.1)	170 (70.3)	56.0 (51.0, 60.0)
Within 200% of poverty level	93 (27.3)	71 (29.3)	54.0 (49.0, 58.0)
$>200\%\text{of}\text{poverty}\text{level}$	2 (0.6)	1 (0.4)	61.0 (61.0, 61.0)
Missing	193	5
Child factors
Sex
Male	264 (49.4)	113 (45.8)	56.0 (50.0, 60.0)
Female	270 (50.6)	134 (54.3)	55.0 (50.0, 60.0)
Breastfeeding durationb
Never breastfed	68 (14.7)	33 (13.8)	52.0 (48.0, 58.0)
$\le 1\text{month}$	118 (25.5)	50 (20.9)	54.0 (48.0, 60.0)
1–6 months	79 (17.1)	33 (13.8)	53.0 (51.0, 57.0)
$>6\text{months}$	197 (42.6)	123 (51.5)	57.0 (52.0, 61.0)
Missing	72	5
History of preschool attendance
Did not attend	108 (31.0)	65 (28.8)	56.0 (52.0, 62.0)
Attended preschool	241 (69.1)	161 (71.2)	55.0 (50.0, 59.0)
Missing	185	21
Intelligence at $10½-\text{year}$ visit (WISC-IV FSIQ)
$\le 79$	49 (15.7)	35 (14.8)	58.0 (51.0, 64.0)
80–99	195 (62.3)	152 (64.1)	55.0 (51.0, 60.0)
$100+$	69 (22.0)	50 (21.1)	53.0 (47.0, 57.0)
Missing	221	10
	$\text{Mean}\pm \text{SD}$	$\text{Mean}\pm \text{SD}$
Child’s age at SRS assessment	$14.18\pm 0.27$	$14.16\pm 0.23$
Missing	207	0
HOME total $z\text{-score}$ (10.5 years)	$-0.02\pm 1.07$	$0.01\pm 1.01$
Missing	89	0

DAPs, dialkyl phosphates; SRS-2, Social Responsiveness Scale, Version 2; PPVT, Peabody Picture Vocabulary Test; CES-D, Center for Epidemiological Studies-Depression Scale; WISC-IV FSIQ, Wechsler Intelligence Scale for Children, Version IV Full Scale IQ.

^a$\mathrm{T}-\text{score}\text{standardized}\text{mean}=50$ ($\text{SD}=10$); higher SRS score indicates more ASD-related traits.

^bIncludes observations with missing data that we imputed with values collected on these variables at earlier or later time points.