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Uteroplacental circulatory disturbance mediated by prostaglandin F(2alpha) in rats exposed to microwaves..

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Nakamura H, Nagase H, Ogino K, Hatta K, Matsuzaki I · 2000

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Microwave radiation at WiFi frequencies reduced placental blood flow in pregnant rats at power levels comparable to smartphone use.

Plain English Summary

Summary written for general audiences

Japanese researchers exposed pregnant rats to microwave radiation at 2.45 GHz (the same frequency as WiFi and microwave ovens) for 90 minutes and found it reduced blood flow to the placenta and increased stress hormones. The effects occurred at power levels too low to cause heating, suggesting the microwaves directly disrupted the pregnancy through biological mechanisms. This raises concerns about wireless device exposure during pregnancy.

Why This Matters

This study provides compelling evidence that microwave radiation can disrupt pregnancy through non-thermal biological effects. The researchers found that 90 minutes of exposure at 2 mW/cm² (2 milliwatts per square centimeter) reduced crucial blood flow between mother and fetus while increasing stress hormones that could threaten pregnancy outcomes. What makes this particularly concerning is that this power density is well within the range of everyday wireless exposures. Your smartphone, when held close to your body, can produce similar or higher power densities, and WiFi routers operate at the exact same 2.45 GHz frequency used in this study. The fact that a drug that dilates blood vessels prevented these effects confirms that the microwaves were causing real physiological changes, not just measurement artifacts. This research adds to a growing body of evidence suggesting that pregnant women should minimize their wireless device exposure, particularly close-to-body use of smartphones and prolonged time near WiFi routers.

Exposure Details

Power Density
2 µW/m²
Source/Device
2450 MHz
Exposure Duration
90 min

Exposure Context

This study used 2 µW/m² for radio frequency:

Building Biology guidelines are practitioner-based limits from real-world assessments. BioInitiative Report recommendations are based on peer-reviewed science. Check Your Exposure to compare your own measurements.

Where This Falls on the Concern Scale

Study Exposure Level in ContextA logarithmic scale showing exposure levels relative to Building Biology concern thresholds and regulatory limits.Study Exposure Level in ContextThis study: 2 µW/m²Extreme Concern1,000 uW/m2FCC Limit10M uW/m2Effects observed in the Slight Concern range (Building Biology)FCC limit is 5,000,000x higher than this exposure level

Study Details

To clarify the effects of microwaves on pregnancy, uterine or uteroplacental blood flow and endocrine and biochemical mediators, including corticosterone, estradiol, prostaglandin E2 (PGE2), and prostaglandin F2α (PGF2α), were measured in rats exposed to continuous-wave (CW) microwave at 2 mW/cm2 incident power density at 2450 MHz for 90 min.

Colonic temperature in virgin and pregnant rats was not significantly altered by microwave treatment...

These results suggest that microwaves (CW, 2 mW/cm2, 2450 MHz) produce uteroplacental circulatory disturbances and ovarian and placental dysfunction during pregnancy, probably through nonthermal actions. The uteroplacental disturbances appear to be due to actions of PGF2α and may pose some risk for pregnancy.

Cite This Study
Nakamura H, Nagase H, Ogino K, Hatta K, Matsuzaki I (2000). Uteroplacental circulatory disturbance mediated by prostaglandin F(2alpha) in rats exposed to microwaves.. Reprod Toxicol 14(3):235-240, 2000.
Show BibTeX
@article{h_2000_uteroplacental_circulatory_disturbance_mediated_1218,
  author = {Nakamura H and Nagase H and Ogino K and Hatta K and Matsuzaki I},
  title = {Uteroplacental circulatory disturbance mediated by prostaglandin F(2alpha) in rats exposed to microwaves..},
  year = {2000},
  
  url = {https://www.sciencedirect.com/science/article/abs/pii/S0890623800000733},
}

Quick Questions About This Study

Japanese researchers exposed pregnant rats to microwave radiation at 2.45 GHz (the same frequency as WiFi and microwave ovens) for 90 minutes and found it reduced blood flow to the placenta and increased stress hormones. The effects occurred at power levels too low to cause heating, suggesting the microwaves directly disrupted the pregnancy through biological mechanisms. This raises concerns about wireless device exposure during pregnancy.