Effects of a 4.7 T static magnetic field on fetal development in ICR mice.

Journal of radiation research · 2001 · Mixed · Low evidence

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MixedLow evidencePaper 3903

Study snapshot

PublicationJournal of radiation research · 2001

Study typeanimal

Reported directionMixed

Evidence ratingLow

Abstract

In order to determine the effects of a 4.7 T static magnetic field (SMF) on fetal development in mice, we evaluated fetal teratogenesis and endochondral ossification following exposure in utero. Pregnant ICR mice were exposed to a 4.7 T SMF from day 7.5 to 9.5 of gestation in a whole-body dose, and sacrificed on day 18.5 of gestation. We examined the incidence of prenatal death, external malformations and fetal skeletal malformations. There were no significant differences observed in the incidence of prenatal death and/or malformations between SMF-exposed mice and control mice. Further, we evaluated the immunoreactivity for the vascular endothelial growth factor (VEGF), which is implicated in angiogenesis and osteogenesis, in the sternum of fetal mice following magnetic exposure. Our studies also indicated that on day 16.5 of gestation following SMF exposure, the immunoreactivity for VEGF was increased compared to unexposed controls. However, it was decreased in the exposed group compared to the control group on day 18.5 of gestation. DNA and proteoglycan (PG) synthesis were also measured in rabbit costal growth plate chondrocytes in vitro. No significant differences were observed in DNA synthesis between the SMF exposed chondrocytes and the control chondrocytes; however, PG synthesis in SMF exposed chondrocytes increased compared to the controls. Based on these results, we suggest that while SMF exposure promoted the endochondral ossification of chondrocytes, it did not induce any harmful effects on fetal development in ICR mice.

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AI evidence extraction

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Study typeanimal

Effect directionmixed

PopulationPregnant ICR mice and fetal mice (in utero exposure); rabbit costal growth plate chondrocytes (in vitro)

Sample sizeNot supplied

Exposurestatic · gestation day 7.5 to 9.5 (in utero exposure); outcomes assessed at gestation day 16.5 and 18.5

Evidence strengthLowConfidence: 74% · Peer reviewed: yes

Main findings

Pregnant ICR mice exposed to a 4.7 T static magnetic field on gestation days 7.5–9.5 showed no significant differences versus controls in prenatal death or external/skeletal malformations when assessed at gestation day 18.5. VEGF immunoreactivity in fetal sternum was increased at gestation day 16.5 after exposure but decreased at gestation day 18.5 compared with controls. In vitro, rabbit chondrocytes showed no significant change in DNA synthesis, while proteoglycan synthesis increased with SMF exposure.

Outcomes measured

Prenatal death
External malformations
Fetal skeletal malformations
Endochondral ossification
VEGF immunoreactivity in fetal sternum
DNA synthesis in rabbit chondrocytes (in vitro)
Proteoglycan (PG) synthesis in rabbit chondrocytes (in vitro)

Limitations

Sample size not reported in abstract
Exposure details beyond field strength and timing (e.g., dosimetry/field uniformity) not described in abstract
Includes both in vivo mouse outcomes and in vitro rabbit chondrocyte outcomes, limiting direct comparability
VEGF findings vary by gestational day (increased at day 16.5, decreased at day 18.5)

View raw extracted JSON

{
  "study_type": "animal",
  "exposure": {
    "band": "static",
    "source": "laboratory magnet (whole-body exposure)",
    "frequency_mhz": null,
    "sar_wkg": null,
    "duration": "gestation day 7.5 to 9.5 (in utero exposure); outcomes assessed at gestation day 16.5 and 18.5"
  },
  "population": "Pregnant ICR mice and fetal mice (in utero exposure); rabbit costal growth plate chondrocytes (in vitro)",
  "sample_size": null,
  "outcomes": [
    "Prenatal death",
    "External malformations",
    "Fetal skeletal malformations",
    "Endochondral ossification",
    "VEGF immunoreactivity in fetal sternum",
    "DNA synthesis in rabbit chondrocytes (in vitro)",
    "Proteoglycan (PG) synthesis in rabbit chondrocytes (in vitro)"
  ],
  "main_findings": "Pregnant ICR mice exposed to a 4.7 T static magnetic field on gestation days 7.5–9.5 showed no significant differences versus controls in prenatal death or external/skeletal malformations when assessed at gestation day 18.5. VEGF immunoreactivity in fetal sternum was increased at gestation day 16.5 after exposure but decreased at gestation day 18.5 compared with controls. In vitro, rabbit chondrocytes showed no significant change in DNA synthesis, while proteoglycan synthesis increased with SMF exposure.",
  "effect_direction": "mixed",
  "limitations": [
    "Sample size not reported in abstract",
    "Exposure details beyond field strength and timing (e.g., dosimetry/field uniformity) not described in abstract",
    "Includes both in vivo mouse outcomes and in vitro rabbit chondrocyte outcomes, limiting direct comparability",
    "VEGF findings vary by gestational day (increased at day 16.5, decreased at day 18.5)"
  ],
  "evidence_strength": "low",
  "confidence": 0.74,
  "peer_reviewed_likely": "yes",
  "keywords": [
    "static magnetic field",
    "4.7 T",
    "ICR mice",
    "pregnancy",
    "fetal development",
    "teratogenesis",
    "skeletal malformations",
    "endochondral ossification",
    "VEGF",
    "chondrocytes",
    "proteoglycan synthesis"
  ],
  "suggested_hubs": [
    {
      "slug": "static-magnetic-fields",
      "weight": 0.9,
      "reason": "Study evaluates developmental and cellular effects of a 4.7 T static magnetic field."
    }
  ]
}

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AI-extracted fields are generated from the abstract and metadata and may be incomplete or incorrect. This material is for informational purposes and is not medical advice.

Identifiers and source

DOI: 10.1269/jrr.42.273
PubMed: 11840644

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