In utero exposure to mercury and childhood overweight or obesity: counteracting effect of maternal folate status

Table 3 Modifying effects of maternal folate levels with mercury levels on child overweight or obesity risk

Mercury quantile	Maternal folate			Crude			Adjusted
Mercury quantile	Maternal folate	n	Case, n(%)	RR	95% CI	p	RR	95% CI	p
Q4	Low	64	39 (60.9)	1.00			1.00
Q4	Adequate	236	103 (43.6)	0.72	0.56–0.91	0.007	0.66	0.51–0.85	0.001
Q1-Q3	Low	195	85 (43.6)	1.00			1.00
Q1-Q3	Adequate	714	289 (40.5)	0.93	0.77–1.11	0.427	0.96	0.80–1.15	0.658
P for interaction						0.095			0.086

Q quartile. Mercury quartile range: Q1 0.39–3.68 μg/L; Q4 3.70–27.8 μg/L. Adequate folate was defined as plasma folate ≥ 20.4 nmol/L; low folate was defined as plasma folate < 20.4 nmol/L
Adjusted for maternal race, smoking, education, parity, pre-pregnancy overweight or obesity, diabetes, hypertensive disorder, preterm birth, fetal growth pattern, and breastfeeding status

ISSN: 1741-7015