Table 6.

Associations of motor skills with quartiles of prenatal blood lead, cadmium or mercury exposure.

			Prenatal blood lead		Prenatal blood cadmium		Prenatal blood mercury
			OR (95% CI)	p	OR (95% CI)	p	OR (95% CI)	p
Balance	Heel to toe: ref 15 steps (vs 1–14): ref Q1	Q4	1.06 (0.81, 1.39)	0.691	0.83 (0.61, 1.12)	0.224	1.05 (0.79, 1.39)	0.718
Ball skills	Beanbag: ref 4–10 throws (vs 1–3): ref Q1	Q4	0.92 (0.70, 1.21)	0.535	0.99 (0.72, 1.35)	0.939	1.13 (0.85, 1.49)	0.410
Manual dexterity	Threading lace: ref 9–21 s (vs 22–105): ref Q1	Q4	0.93 (0.70, 1.24)	0.634	0.95 (0.69, 1.30)	0.946	1.21 (0.90, 1.61)	0.206
	Peg board
	Preferred hand: ref 15–22 s (vs 23–46): ref Q1	Q4	1.23 (0.94, 1.63)	0.138	1.04 (0.76, 1.42)	0.915	1.11 (0.84, 1.48)	0.460
	Non-preferred hand: ref 15–25 (vs 25–62 s): ref Q1	Q4	1.04 (0.79, 1.36)	0.792	1.06 (0.78, 1.45)	0.721	0.78 (0.59, 1.03)	0.083

Reference categories: lead < 5 µg/dl, cadmium < 0.25 µg/l, mercury < 2.00 µg/l.

Participants with poor attention excluded.

Adjusted for: sex, maternal education, smoking in pregnancy, alcohol in pregnancy, maternal age and parity.