Table 1.

Sample characteristics for mothers and daughters enrolled in ALSPAC^a with maternal serum PFAS^b concentrations and ALSPAC-adapted MCDI^c sub-scores at 15 or 38 months of age (n = 432).

	N	Median	IQRd
Maternal PFAS exposure
Perfluorooctane sulfonate (PFOS) (ng/mL)	432	19.8	15.0, 24.95
Perfluorooctanoate (PFOA) (ng/mL)	432	3.7	2.8, 4.8
Perfluorohexane sulfonate (PFHxS) (ng/mL)	432	1.6	1.2, 2.2
Perfluorononanoate (PFNA) (ng/mL)	432	0.5	0.4, 0.7
Adapted MCDI scores at 15 months
Nonverbal communication score	419	15.0	13.0, 17.0
Verbal comprehension score	419	10.0	8.0, 12.0
Vocabulary comprehension and production score	419	87.0	62.0, 124.0
Social development score	420	18.0	14.5, 22.0
Adapted MCDI scores at 38 months
Language score	400	314.0	298.5, 322.0
Intelligibility score	404	6.0	6.0,6.0
Communicative ability score	403	5.0	4.0, 6.0
Covariates
Maternal CCEIe score at 8 months	405	8.0	5.0, 13.0
Gestational age at sample collection, weeks	432	15.0	10.0, 28.0
	N	%
Maternal education
Less than O level	83	19.21
O level	138	31.94
Greater than O level	196	45.37
Missing	15	3.47
Maternal age at delivery
< 25 years	88	20.37
25–29 years	163	37.73
≥ 29 years	181	41.9
Maternal alcohol consumptionf
Yes	223	51.62
No	192	44.44
Missing	17	3.94
Maternal smoking statusf
Yes	98	22.69
No	319	73.84
Missing	15	3.47
Parity
0	205	47.45
1+	208	48.15
Missing	19	4.4

^aAvon Longitudinal Study of Parents and Children.

^bPerfluoroalkyl substances.

^cMacArthur Communicative Development Inventories.

^dInterquartile range.

^eCrown-Crisp Experiential Index.

^fDuring first three months of pregnancy.