Exposure to static magnetic field delays induced preterm birth occurrence in mice

Abstract

The purpose of this study was to demonstrate that daily 40-minute whole body exposure to an inhomogeneous static magnetic field (SMF) prolongs induced preterm birth (PTB) in mice. The murine model for PTB induction was performed by the administration of 25 μg/animal lipopolysaccharide (LPS) intraperitoneally. The applied SMF was an inhomogeneous gradient field with 2.8-476.7 millitesla peak-to-peak magnetic induction range by 10 mm lateral periodicity. During SMF exposure, mice were free to move in their cage. The fetal development and the delivery were normal in animals that were exposed to SMF but not treated with LPS. SMF in these cases did not influence the term of delivery. In LPS-challenged animals, SMF exposure prolonged the time of PTB occurrence from 17.43 h (n = 7) to 21.93 h (n = 15) after the challenge (P < .05). Exposure to inhomogeneous SMF may have a valuable effect in the prevention of PTB and may have clinical relevance to humans.