Study type: Epidemiological study

Association Between Maternal Exposure to Magnetic Field Nonionizing Radiation During Pregnancy and Risk of Attention-Deficit/Hyperactivity Disorder in Offspring in a Longitudinal Birth Cohort. epidem.

Published in: JAMA Netw Open 2020; 3 (3): e201417

Aim of study (acc. to author)

A cohort study was conducted in the USA to investigate the association between maternal exposure to extremely low frequency magnetic fields during pregnancy and the risk of ADHD in their children.

Further details

The article was retracted and replaced on February 18, 2021, to add a figure to Supplement 1 and fix errors in the abstract, text, tables and the figure in the article. The summary presented here refers to the actual, revised version of the article.

Endpoint/type of risk estimation

Exposure

Assessment

Exposure groups

Group Description
Reference group 1 maternal exposure to magnetic fields, 24 h-measurement: < 0.13 µT
Group 2 maternal exposure to magnetic fields, 24 h-measurement: 0.13 - < 1.4 µT
Group 3 maternal exposure to magnetic fields, 24 h-measurement: 0.14 - < 1.5 µT
Group 4 maternal exposure to magnetic fields, 24 h-measurement: 0.15 - < 1.6 µT
Group 5 maternal exposure to magnetic fields, 24 h-measurement: 0.16 - < 1.7 µT
Group 6 maternal exposure to magnetic fields, 24 h-measurement: 0.17 - < 1.8 µT
Group 7 maternal exposure to magnetic fields, 24 h-measurement: 0.18 - < 1.9 µT
Group 8 maternal exposure to magnetic fields, 24 h-measurement: 0.19 - < 2.0 µT
Group 9 maternal exposure to magnetic fields, 24 h-measurement: ≥ 2.0 µT

Population

Study size

Type Value
Eligible 1,482
Evaluable 1,454
Statistical analysis method: ( adjustment: )

Conclusion (acc. to author)

Using a continuous exposure measure in the analyses, children whose mothers were exposed to high magnetic field strengths had no higher risk of ADHD (HR 1.1, CI 0.8-1.5). Similar results were observed for children with ADHD that persisted into adolescence (HR 1.3, CI 0.9-1.9). In categorical analyses of the children with ADHD, among 8 levels of exposures, 2 of 8 exposure groups were associated with risk for ADHD. In categorical analyses, associations were observed for 4 of 8 levels of exposure for children with persistent ADHD. For children with ADHD and immune-related comorbidities (asthma or atopic dermatitis), there were no associations with maternal exposure to magnetic fields in continuous scale analyses (HR 1.2, CI 0.8-1.7), but there were associations in categorical analyses at all levels of exposure. However, the associations observed were not linear and confidence intervals around the effect sizes were wide.
The authors concluded that in this study, in utero exposure to some, but not all, high levels of magnetic fields were associated with a higher risk of ADHD. However, the associations observed were inconsistent and nonlinear.

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