Table 4. In-utero Exposure to Magnetic Fields (MFs) and the Risk of Obesity/Overweight in Offspring in Relation to Other Risk Factors for Childhood Obesity.

MF exposure level1	N of Children	aOR2	95% CI (p-value)	p-value for interaction3
Maternal pre-pregnancy BMI				0.001
≤25
≤1.5 mG	164	Reference
>1.5 mG	349	1.09	0.54–2.21 (0.81)
>25
≤1.5 mG	75	Reference
>1.5 mG	145	2.91	1.33–6.33 (<0.01)
Maternal pre-existing or gestational diabetes				0.01
No
≤.5 mG	210	Reference
>1.5 mG	447	1.43	0.83–2.44 (0.19)
Yes
≤1.5 mG	22	Reference
>1.5 mG	30	11.01	1.42–85.58 (0.02)
Smoking during pregnancy				0.19
No
≤1.5 mG	217	Reference
>1.5 mG	449	1.52	0.88–2.65 (0.14)
Yes
≤1.5 mG	22	Reference
>1.5 mG	45	4.87	1.06–22.25 (0.04)
Breastfeeding				0.34
Yes
≤1.5 mG	223	Reference
>1.5 mG	444	1.64	0.94–2.87 (0.08)
No
≤1.5 mG	16	Reference
>1.5 mG	49	2.51	0.36–17.40 (0.35)

190^th percentile of 24 hour MF exposure in milliGauss (mG).

2adjusted odd ratio of obesity/overweight defined as >97.5 percentile of weight-for-age based on CDC criteria²⁴. Odds ratio from GEE model with repeated measurements, adjusted for child's exact age at each weight measurement, child gender, maternal age at delivery, maternal pre-pregnancy BMI, race, education level, smoking during pregnancy, and breastfeeding. Further adjustment for maternal parity, prior or gestational diabetes, income, preterm delivery, and childhood characteristics such as fruit and vegetable intake, TV watching, and exercise did not change results.

3Interaction based on log-likelihood ratio test.