SAR calculation in semi-homogeneous human models of pregnancy for RF exposure

Recently, there has been increasing concern regarding the safety of exposure to radio-frequency electromagnetic fields (RF-EMFs) in the fetus during pregnancy. We generated anatomically realistic models of fetus including gestational tissues in the second and third trimesters of pregnancy on the basis of magnetic resonance imaging data from healthy volunteers or a patient and developed semi-homogeneous whole-body models containing the anatomically realistic fetal models. The semi-homogeneous models were included about 20 different types of fetal and gestational tissues and composed of voxels of 2 × 2 × 2 mm³. In this paper, we estimated the specific absorption rate in fetuses in the second and third trimesters of pregnancy for whole-body exposure to RF-EMFs using the finite-difference time-domain method.