The effects of radiofrequency exposure on adverse female reproductive outcomes: A systematic

Abstract

The effects of radiofrequency exposure on adverse female reproductive outcomes: A systematic review of human observational studies with dose–response meta-analysis (WHO SR 3 female) My note: See WHO Radiofrequency EMF Health Risk Assessment Monograph (EHC series) Johnson EE, Kenny RPW, Adesanya AM, Richmond C, Beyer F, Calderon C, Rankin J, Pearce MS, Toledano M, Craig D, Pearson F. The effects of radiofrequency exposure on adverse female reproductive outcomes: A systematic review of human observational studies with dose-response meta-analysis. Environ Int. 2024 Jun 12;190:108816. doi: 10.1016/j.envint.2024.108816. Abstract Background To inform radiofrequency electromagnetic field (RF-EMF) exposure guidelines the World Health Organization (WHO) is bringing together evidence on RF-EMF in relation to health outcomes prioritised for evaluation by experts in this field. Given this, a network of topic experts and methodologists have conducted a series of systematic reviews collecting, assessing, and synthesising data of relevance to these guidelines. Here we present a systematic review of the effect of RF-EMF exposure on adverse pregnancy outcomes in human observational studies which follows the WHO handbook for guideline development and the COSTER conduct guidelines. Methods We conducted a broad, sensitive search for potentially relevant records within the following bibliographic databases: MEDLINE; Embase; and the EMF Portal. Grey literature searches were also conducted through relevant databases (including OpenGrey), organisational websites and via consultation of RF-EMF experts. We included quantitative human observational studies on the effect of RF-EMF exposure in adults’ preconception or pregnant women on pre-term birth, small for gestational age (SGA; associated with intrauterine growth restriction), miscarriage, stillbirth, low birth weight (LBW) and congenital anomalies. In blinded duplicate, titles and abstracts then full texts were screened against eligibility criteria. A third reviewer gave input when consensus was not reached. Citation chaining of included studies was completed. Two reviewers’ data extracted and assessed included studies for risk of bias using the Office of Health Assessment and Translation (OHAT) tool. Random effects meta-analyses of the highest versus the lowest exposures and dose–response meta-analysis were conducted as appropriate and plausible. Two reviewers assessed the certainty in each body of evidence using the OHAT GRADE tool. Results We identified 18 studies in this review; eight were general public studies (with the general public as the population of interest) and 10 were occupational studies (with the population of interest specific workers/workforces). General public studies. From pairwise meta-analyses of general public studies, the evidence is very uncertain about the effects of RF-EMF from mobile phone exposure on preterm birth risk (relative risk (RR) 1.14, 95% confidence interval (CI): 0.97–1.34, 95% prediction interval (PI): 0.83–1.57; 4 studies), LBW (RR 1.14, 95% CI: 0.96–1.36, 95% PI: 0.84–1.57; 4 studies) or SGA (RR 1.13, 95% CI: 1.02–1.24, 95% PI: 0.99–1.28; 2 studies) due to very low-certainty evidence. It was not feasible to meta-analyse studies reporting on the effect of RF-EMF from mobile phone exposure on congenital anomalies or miscarriage risk. The reported effects from the studies assessing these outcomes varied and the studies were at some risk of bias. No studies of the general public assessed the impact of RF-EMF exposure on stillbirth. Occupational studies. In occupational studies, based on dose– response meta-analyses, the evidence is very uncertain about the effects of RF-EMF amongst female physiotherapists using shortwave diathermy on miscarriage due to very low-certainty evidence (OR 1.02 95% CI 0.94–1.1; 2 studies). Amongst offspring of female physiotherapists using shortwave diathermy, the evidence is very uncertain about the effects of RF-EMF on the risk of congenital malformations due to very low-certainty evidence (OR 1.4, 95% CI 0.85 to 2.32; 2 studies). From pairwise meta-analyses, the evidence is very uncertain about the effects of RF-EMF on the risk of miscarriage (RR 1.06, 95% CI 0.96 to 1.18; very low-certainty evidence), pre-term births (RR 1.19, 95% CI 0.32 to 4.37; 3 studies; very low- certainty evidence), and low birth weight (RR 2.90, 95% CI: 0.69 to 12.23; 3 studies; very low-certainty evidence). Results for stillbirth and SGA could not be pooled in meta-analyses. The results from the studies reporting these outcomes were inconsistent and the studies were at some risk of bias. Discussion Most of the evidence identified in this review was from general public studies assessing localised RF-EMF exposure from mobile phone use on female reproductive outcomes. In occupational settings, each study was of heterogenous whole-body RF-EMF exposure from radar, short or microwave diathermy, surveillance and welding equipment and its effect on female reproductive outcomes. Overall, the body of evidence is very uncertain about the effect of RF-EMF exposure on female reproductive outcomes. Further prospective studies conducted with greater rigour (particularly improved accuracy of exposure measurement and using appropriate statistical methods) are required to identify any potential effects of RF-EMF exposure on female reproductive outcomes of interest. Open access paper: sciencedirect.com

AI evidence extraction

Main findings

This systematic review of 18 human observational studies found very low-certainty evidence regarding associations between RF-EMF exposure and adverse female reproductive outcomes. Meta-analyses for general public mobile phone exposure and several occupational exposure groupings produced effect estimates close to null with wide uncertainty, and several outcomes could not be pooled due to heterogeneity and inconsistent results. The authors conclude the overall evidence is very uncertain and call for more rigorous prospective studies with improved exposure assessment.

Outcomes measured

• Preterm birth
• Small for gestational age (SGA)
• Miscarriage
• Stillbirth
• Low birth weight (LBW)
• Congenital anomalies/malformations

Limitations

• Human evidence limited to observational studies
• Very low certainty of evidence for pooled outcomes (as assessed by OHAT GRADE)
• Some outcomes could not be meta-analysed due to heterogeneity/infeasibility
• Inconsistent findings for some outcomes (e.g., congenital anomalies, miscarriage in some settings)
• Included studies had some risk of bias
• Exposure assessment accuracy noted as needing improvement

Suggested hubs

• who-icnirp (0.86)
  Systematic review conducted to inform WHO RF-EMF exposure guidelines and uses WHO/OHAT methods.
• cell-phones (0.74)
  Most included general public studies assessed localized RF-EMF exposure from mobile phone use.
• occupational-exposure (0.7)
  Includes 10 occupational studies with RF-EMF exposures such as diathermy and radar.

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    "publication_year": 2024,
    "study_type": "systematic_review",
    "exposure": {
        "band": "RF",
        "source": "mobile phone; occupational RF-EMF (e.g., shortwave diathermy, radar, microwave diathermy, surveillance, welding equipment)",
        "frequency_mhz": null,
        "sar_wkg": null,
        "duration": null
    },
    "population": "Adults in preconception or pregnant women (general public) and specific occupational groups (e.g., female physiotherapists using shortwave diathermy)",
    "sample_size": 18,
    "outcomes": [
        "Preterm birth",
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    "main_findings": "This systematic review of 18 human observational studies found very low-certainty evidence regarding associations between RF-EMF exposure and adverse female reproductive outcomes. Meta-analyses for general public mobile phone exposure and several occupational exposure groupings produced effect estimates close to null with wide uncertainty, and several outcomes could not be pooled due to heterogeneity and inconsistent results. The authors conclude the overall evidence is very uncertain and call for more rigorous prospective studies with improved exposure assessment.",
    "effect_direction": "unclear",
    "limitations": [
        "Human evidence limited to observational studies",
        "Very low certainty of evidence for pooled outcomes (as assessed by OHAT GRADE)",
        "Some outcomes could not be meta-analysed due to heterogeneity/infeasibility",
        "Inconsistent findings for some outcomes (e.g., congenital anomalies, miscarriage in some settings)",
        "Included studies had some risk of bias",
        "Exposure assessment accuracy noted as needing improvement"
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    "evidence_strength": "high",
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    "peer_reviewed_likely": "yes",
    "stance": "neutral",
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    "summary": "This WHO-aligned systematic review synthesized 18 human observational studies on RF-EMF exposure and adverse pregnancy outcomes. For general public mobile phone exposure and heterogeneous occupational RF-EMF sources, pooled analyses generally yielded very low-certainty evidence with substantial uncertainty and some outcomes not poolable. The authors conclude the overall body of evidence is very uncertain and recommend more rigorous prospective studies with better exposure measurement.",
    "key_points": [
        "The review followed WHO guideline-development methods and assessed risk of bias using the OHAT tool.",
        "Eighteen observational studies were included: eight general public studies and 10 occupational studies.",
        "General public evidence on mobile phone RF-EMF and preterm birth, low birth weight, and SGA was rated very low certainty and described as very uncertain.",
        "Evidence on congenital anomalies and miscarriage in the general public could not be meta-analysed and reported effects varied with some risk of bias.",
        "No general public studies assessed stillbirth in relation to RF-EMF exposure.",
        "Occupational evidence (including shortwave diathermy and other RF sources) was heterogeneous and generally very low certainty, with some outcomes not poolable and inconsistent results.",
        "The authors conclude the overall evidence is very uncertain and call for improved prospective studies and exposure assessment."
    ],
    "categories": [
        "Systematic Reviews",
        "Pregnancy & Reproductive Outcomes",
        "Mobile Phones",
        "Occupational Exposure"
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    "tags": [
        "Systematic Review",
        "Dose-Response Meta-Analysis",
        "RF-EMF",
        "Mobile Phone Use",
        "Occupational Exposure",
        "Pregnancy Outcomes",
        "Preterm Birth",
        "Low Birth Weight",
        "Small For Gestational Age",
        "Miscarriage",
        "Congenital Anomalies",
        "Stillbirth",
        "OHAT Risk Of Bias",
        "WHO Guideline Development"
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    "social": {
        "tweet": "WHO-aligned systematic review (18 observational studies) found very low-certainty evidence on RF-EMF exposure (mobile phones and occupational sources) and adverse pregnancy outcomes; overall effects remain very uncertain and better prospective studies are needed.",
        "facebook": "A WHO-aligned systematic review of 18 human observational studies examined RF-EMF exposure (including mobile phone use and occupational sources like diathermy/radar) and outcomes such as preterm birth, low birth weight, SGA, miscarriage, stillbirth, and congenital anomalies. The authors report very low-certainty evidence overall and conclude the effects remain very uncertain, highlighting the need for more rigorous prospective research and improved exposure measurement.",
        "linkedin": "In a WHO-aligned systematic review with dose–response meta-analysis (Environ Int, 2024), 18 human observational studies on RF-EMF exposure (general public mobile phone use and heterogeneous occupational sources) and adverse female reproductive outcomes were synthesized. Across outcomes including preterm birth, LBW, SGA, miscarriage, stillbirth, and congenital anomalies, the certainty of evidence was generally very low and several outcomes could not be pooled due to heterogeneity/inconsistency. The authors conclude the overall evidence is very uncertain and call for better-designed prospective studies with improved exposure assessment."
    }
}

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