A prospective cohort study with up to 21 years of follow-up

Abstract

OPS 27: Radiation, EMF and morbidity, Room 210, Floor 2, August 27, 2019, 10:30 AM - 12:00 PM Background/Aim: Both human and animal studies have shown that in-utero exposure to magnetic field non-ionizing radiation (MF) could impact neurodevelopment in offspring. Taking advantage of a large prospective cohort study with objective measurements of maternal MF exposure during pregnancy, we examined the relationship between maternal MF exposure level in pregnancy and the risk of headaches and migraines in offspring. Methods: Consented pregnant members of Kaiser Permanente Northern California were asked to wear an EMDEX meter for 24 hours to measure MF exposure levels from all sources during pregnancy. We used the 95th percentile of the 24-hour MF measurements to categorize MF level, focusing on high MF level. Offspring were followed throughout their childhood to identify clinical diagnoses of recurrent headaches (two or more) and migraines from our medical records. A total of 734 mother-child pairs were included in the analysis. The Cox Proportional Hazards regression was used for analysis, accounting for varying follow-up times. Results: After controlling for multiple confounders, the children whose mothers were exposed to higher MF levels [95th percentile ≥ 5 milligauss (mG)] had a 73% higher risk of recurrent headache with or without migraine [hazard ratio (HR) (OR)=1.73, 95% confidence interval (CI): 1.11-2.69] compared to children of mothers whose MF level was lower than 5 mG. The association was stronger for offspring with both headache and migraine diagnoses (HR=2.43, 95% CI: 1.28-4.61) with a dose-response relationship. The association appears to be stronger among Whites and male offspring. Conclusions: Maternal high MF exposure during pregnancy is associated with an increased risk of recurrent headaches and migraines in offspring. Some maternal and children’s characteristics such as race/ethnicity and sex may contribute to the susceptibility to the exposure. This is the first human study with MF exposure objectively measured during pregnancy to show such a long-lasting MF impact.