Study type: Epidemiological study (observational study)

Residential exposure to 50 Hz magnetic fields and the association with miscarriage risk: a 2-year prospective cohort study. epidem.

Published in: PLoS One 2013; 8 (12): e82113

Aim of study (acc. to author)

A cohort study was conducted in China to investigate the association between residential exposure to 50 Hz magnetic fields and the miscarriage risk.

Endpoint/type of risk estimation

Type of risk estimation: (relative risk (RR))



Exposure groups

Group Description
Reference group 1 unexposed, magnetic field strength: < 0.1 µT
Group 2 exposed, magnetic field strength: ≥ 0.1 µT
Group 3 group A, magnetic field strength: 0.1 - < 0.4µT
Group 4 group B, magnetic field strength: 0.4 µT - 4.26 µT


Study size

Type Value
Total 449
Evaluable 413

follow-up every 2 months

Statistical analysis method: ( adjustment: )

Conclusion (acc. to author)

Of all 562 magnetic field strength measurements, 33.6% of the measurements were lower than 0.05 µT, 13.3% of the measurements were higher than 0.4 µT, and 4.6% of measurements were higher than 1.0 µT. The median was 0.099 µT.
No significantly increased risk of miscarriage in the exposed group was found to be associated with the average front-door exposure (RR 1.4; CI 0.6-3.1). However, miscarriage risk was found to be significantly associated with maximum alley exposure in the exposed group (RR 2.35, CI 1.18-4.71), after adjusting for confounders the hazard ratio was 1.72 (CI 1.10-2.69).
The authors concluded that the association between miscarriage risk and the exposure to magnetic fields was not confirmed in this study although the miscarriage incidence was shown to be positively associated with the maximum alley magnetic field exposure.

Study funded by

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