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This systematic review and meta-analysis evaluated the current evidence on the association between radiofrequency electromagnetic field (RF-EMF) exposures during pregnancy and adverse reproductive health outcomes in offspring of experimental animals. Of total 88 papers included in the review, 65 were on rats, 20 in mice and 3 in other animals. The health outcomes were grouped into fecundity (i.e., litter size, embryonic/foetal losses), offspring health at birth (i.e., decrease of weight or length, congenital malformations, changes of sex ratio) and delayed effects on the offspring health (i.e., memory function, female infertility, etc.). The associations between RF-EMF exposure (i.e., whole body average Specific absorption rate, SAR) and the health outcomes and their dose-response relationships were examined. The certainty of the evidence was also evaluated on the three levels of risk of bias (RoB): high, some or low concern.
For fecundity, a whole-body average SAR of 4.92 W/kg had no effect of exposure (means difference, MD 0.05; 95% Confidence Interval, CI - 0.21 to 0.30) on litter size. A whole-body average SAR of 20.26 W/kg, showed a significant increase of the resorbed or dead foetus in exposed animals (Odds ratio, OR 1.84; 95% CI 1.27 to 2.66). Similar results were shown in the dose–response analysis. For offspring health at birth, a whole-body average SAR of 9.83 W/kg showed a small decrease in foetal weight among exposed animals standardized mean difference (SMD) 0.31; 95% CI 0.15 to 0.48). A whole-body average SAR of 4.55 W/kg showed a moderate decrease in foetal length at birth (SMD 0.45; 95% CI 0.07 to 0.83) in exposed animals. A whole-body average SAR of 6.75 W/kg showed a moderate increase in the proportion of foetuses with malformations (SMD - 0.45; 95% CI -0.68 to - 0.23) in exposed animals. A whole-body average SAR of 16.63 W/kg showed an increased incidence of litters with malformed foetuses (OR 3.22; 95% CI 1.9 to 5.46) in exposed animals. Similar results were shown in the dose–response analysis. For delayed effects, RF-EMF exposure was not associated with: i) detrimental effects on brain weight (SMD 0.10; 95% CI - 0.09 to 0.29, ii) learning and memory functions (SMD - 0.54; 95% CI - 1.24 to 0.17); and decrease in the size of litters conceived by the second generation female offspring (SMD 0.08; 95% CI - 0.39 to 0.55). However, the exposure was associated with a large detrimental effect on motor activity functions (SMD 0.79; 95% CI 0.21 to 1.38) and a moderate detrimental effect on motor and sensory functions (SMD - 0.66; 95% CI - 1.18 to - 0.14).
The study showed that RF-EMF exposure during pregnancy does not have an adverse effect on fecundity, likely affects offspring health at birth, probably does not affect offspring brain weight and may not decrease female offspring fertility; may have a detrimental impact on neurobehavioral functions. Most of the studies contributing to the pooled results, including reported significant associations, had either ‘high’ or ‘some’ RoB level.
Effects of Radiofrequency Electromagnetic Field (RF-EMF) exposure on pregnancy and birth outcomes: A systematic review of experimental studies on non-human mammals
The review provides state-of-the art evidence on whether in utero RF-EMF exposure is related to adverse reproductive health outcomes in experimental animal offspring. Though some of the study findings show significant associations, the studies yielding those results have high or some RoB indicating limited certainty of the results. This is primarily due to poor quality of the studies in terms of their methodological limitations, including small sample size in experimental group, limited confidence in outcome assessment, lack of blinding, inadequate exposure characterisation and dosimetry, inadequate assessment of temperature rise and lack of randomisation. Similar limitations have been highlighted in an ARPANSA review (Karipidis et al., 2023) assessing impact of RF-EMF exposure in fauna and flora in the environment.
The review reported whole body average SAR levels in the included experiments, which are far above the human safety limits given in the Australia Standard (e.g., RPS-S1) and internationally (the ICNIRP limits) and are generally not encountered in general public environments (e.g. from telecommunications transmitters or wireless devices). Therefore, the findings of the review may have a limited relevance to current RF-EMF exposure risk assessment for humans. Based on the current scientific evidence, it is the assessment of ARPANSA that there is no substantiated evidence that RF-EMF exposures at levels below the limits set in the ARPANSA Safety Standard cause any adverse health effects, including adverse reproductive health effects, in human populations.
The review forms part of the World Health Organization’s ongoing project to assess potential health effects of RF-EMF in the general and working population and ARPANSA is supporting this process.