Pregnancy serum concentrations of perfluorinated alkyl substances and offspring behaviour and motor development at age 5–9 years – a prospective study

Table 4 Associations ^a between pregnancy levels of PFOS/PFOA (ng/ml) and offspring SDQ-total and hyperactivity score

			Combined (N = 1,106)^e		Greenland (n = 526)		Ukraine (n = 491)		Poland (n = 89)
Scale (score range)			Difference	95% CI	Difference	95% CI	Difference	95% CI	Difference	95% CI
SDQ (0–40) ^b	PFOA	Low	Ref	-	Ref	-	Ref	-	Ref	-
		Medium	0.3	−0.5, 1.0	0.7	−0.4, 1.7	−0.9	−1.9, 0.1	0.8	−1.9, 3.4
		High	0.7	−0.2, 1.5	0.5	−0.6, 1.5	−0.3	−1.3, 0.7	1.8	−0.8, 4.5
		Continuous^d	0.1	−0.5, 0.7	0.3	−0.6, 1.3	−0.5	−1.3, 0.4	2.1	−0.4, 4.7
Hyperactivity (0–10) ^c		Low	Ref	-	Ref	-	Ref	-	Ref	-
		Medium	0.1	−0.3, 0.4	0.5	0.0, 1.0	−0.3	−0.7, 0.1	1.1	−0.4, 2.6
		High	0.5	0.1, 0.9	0.6	0.1, 1.1	−0.2	−0.6, 0.2	0.9	−0.6, 2.4
		Continuous^d	0.3	0.0, 0.5	0.5	0.1, 0.9	−0.1	−0.5, 0.2	1.2	−0.3, 2.6
SDQ (0–40) ^b	PFOS	Low	Ref	-	Ref	-	Ref	-	Ref	-
		Medium	0.1	−1.0, 0.8	1.3	0.3, 2.4	−1.0	−2.0, 0.0	−0.1	−2.7, 2.5
		High	1.1	−0.1, 2.3	1.1	0.1, 2.2	−1.0	−2.2-0.0	2.0	−0.6, 4.6
		Continuous^d	0.3	−0.3, 1.0	1.0	0.1, 2.0	−1.0	−1.6, 0.2	2.6	−0.5, 5.7
Hyperactivity (0–10) ^c		Low	Ref	-	Ref	-	Ref	-	Ref	-
		Medium	0.1	−0.3-0.5	0.4	−0.1, 0.8	−0.2	−0.6, 0.2	0.9	−0.5, 2.4
		High	0.5	0.0, 1.0	0.3	−0.2, 0.7	−0.1	−0.5, 0.3	1.3	−0.1, 2.8
		Continuous^d	0.2	−0.1, 0.5	0.3	−0.1, 0.7	−0.1	−0.4, 0.3	1.5	−0.3, 3.2

CI, confidence interval; PFOA, perfluorooctanoate; PFOS, perfluorooctane sulfonate; Ref, reference group; SDQ, strength and difficulties questionnaire.
^aAdjusted for: maternal cotinine level during pregnancy, maternal alcohol consumption at conception, maternal age at pregnancy, gestational age at blood-sampling and child sex. ^bHigh scores indicate behavioural problems. ^cHigh scores indicate more hyperactive behaviour. ^dβ = the change in score according to one natural-log unit increase in PFOA and PFOS. ^eAdditionally adjusted for country.

ISSN: 1476-069X