OP05.06: Fetal safety of prophylactic electromagnetic field administration for fetal growth restriction prevention: an experimental study on pregnant rats

Administration of pulsed electromagnetic field (PEMF) and radiofrequency electromagnetic field (RF-EMF) enhance neovascularisation and angiogenesis. Hence, EMF treatments could be hypothesised to prevent or treat early-onset fetal growth restriction. We aimed to examine the morphological and histopathological effects of PEMF and RF-EMF administrations separately or in combination during early (first 10 days) and late (10-20 days) pregnancy in a rat model before human use. Thirty-two Wistar-Albino female rats were included, forming 8 experimental groups. Rats were exposed to EMF in early and late pregnancy using PEMF, RF-EMF, and combined treatments. Various biometric measurements in term fetuses, fetal histopathology, and Heat Shock Protein 70 (HSP-70) immunostaining in the placenta were evaluated. Except intracranial hemorrhage foci observed in 2 fetuses exposed to combined treatment, fetal brain, lung, liver, heart, intestine, and kidney tissues were normal. Several fetal weight-standardised biometric measurements, including head-crown length and biparietal diameter in fetuses exposed to RF during early pregnancy were significantly higher compared to other groups. Placental weights were similar among the study groups. Intense staining with HSP70 was detected in placentas exposed to PEMF and RF-EMF in the first ten days of pregnancy. All external organs and the skeletal systems were assessed as normal in all groups. EMF administration during pregnancy at the current route and dose does not appear to be significantly teratogenic and is relatively safe for the fetus. Increased fetal growth with unaltered placental weight might be associated with increased uteroplacental blood flow or partial placental injury secondary to tissue stress. Possible adverse effects of combined EMF use on the fetal brain should be investigated in further studies. Supported by grants from Suleyman Demirel University Scientific Research Projects Coordination Unit (research project no, TTU-2023-8999)