Background Data on the effects of extremely low frequency electromagnetic fields (ELF-EMF) on pregnancy outcomes are inconclusive.
Objective To study the relation between maternal cumulative exposure to ELF-EMF during pregnancy and the risk of prematurity or small for gestational age (SGA) in a pooled analysis of two French birth cohorts.
Methods Elfe and Epipage2 are both population-based birth cohorts initiated in 2011 and included 18 329 and 8400 births, respectively. Health data and household, mother and child characteristics were obtained from medical records and questionnaires at maternity and during follow-up. A job exposure matrix was used to assess cumulative exposure to ELF-EMF during three periods: (1) until 15 weeks of gestation, (2) until 28 weeks of gestation and (3) until 32 weeks of gestation. Analyses were restricted to single live births in mainland France and to mothers with documented jobs (N=19 894). Adjusted logistic regression models were used.
Results According to the period studied, 3.2%–4% of mothers were classified as highly exposed. Results were heterogeneous. Increased risks of prematurity were found among low exposed mothers for the three periods, and no association was observed among the most exposed (OR1=0.92 (95% CI 0.74 to 1.15); OR2=0.98 (95% CI 0.80 to 1.21); OR3=1.14 (95% CI 0.92 to 1.41)). For SGA, no association was observed with the exception of increased risk among the low exposed mothers in period 2 and the most exposed in period 3 (OR=1.25 (95% CI 1.02 to 1.53)).
Conclusion Some heterogeneous associations between ELF-EMF exposure and prematurity and SGA were observed. However, due to heterogeneity (ie, their independence regarding the level of exposure), associations cannot be definitely explained by ELF-EMF exposure.
- extremely low frequency electromagnetic fields
- maternal exposure
- occupational exposure
- small for gestational age
Statistics from Altmetric.com
Contributors Each author contributed to the realisation of this manuscript. LM, GB and IB led the initial design of this analysis. LM led the literature review, data analysis and manuscript writing. RG, CP, CC, IB and GB helped conduct the literature review and to prepare the Materials and methods section. RG, CP, EC and RdS participated in the exposure assessment method and contributed to the preparation of the Discussion section. RG, LM-M and SO helped performed the statistical analyses. MC, CZ and LM-M helped in data management and creation of the statistical variables needed in the framework of this study. M-AC and P-YA coordinated the Elfe and Epipage2 studies, respectively, and helped in the implementation of the methodology to compile data from both cohorts. All authors have revised the article critically and approved the current version of the manuscript.
Funding This work was supported by the Ministry of Higher Education and Research (doctoral fellowship). The Elfe survey is a joint project between the French Institute for Demographic Studies (Ined) and the National Institute for Health and Medical Research (Inserm), in partnership with the French blood transfusion service (Etablissement français du sang, EFS), Santé Publique France, the French National Institute for Statistics and Economic Studies (INSEE), the Direction générale de la santé (DGS, part of the Ministry of Health and Social Affairs), the Direction générale de la prévention des risques (DGPR, Ministry for the Environment), the Direction de la recherche, des études, de l’évaluation et des statistiques (DREES, Ministry of Health and Social Affairs), the Département des études, de la prospective et des statistiques (DEPS, Ministry of Culture) and the Caisse nationale des allocations familiales (CNAF), with the support of the Ministry of Higher Education and Research and the Institut national de la jeunesse et de l’éducation populaire (INJEP). Via the RECONAI platform, it receives a government grant managed by the National Research Agency under the 'Investissements d’avenir' programme (ANR-11-EQPX-0038). The Epipage2 study was supported by the French Institute of Public Health Research, French Health Ministry, National Institute of Health and Medical Research, National Institute of Cancer, National Solidarity Fund for Autonomy, grant ANR-11-EQPX-0038 from the National Research Agency through the French Equipex Program of Investments in the Future, and the PremUp Foundation.
Competing interests None declared.
Patient consent for publication Not required.
Ethics approval The Elfe and Epipage2 studies were approved by the French National Commission for Data Protection and Liberties, the National Council for Statistical Information, and the National Committee for the Protection of Persons. A signed informed consent was obtained from all enrolled families in the Elfe study, and an oral informed consent was obtained in the Epipage2 study.
Provenance and peer review Not commissioned; externally peer reviewed.
Data availability statement No data are available.
If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.