Cuneo BF, et al. - Researchers performed a retrospective review of controls and fetuses from anti-Ro/SSA positive pregnancies that underwent MCG and echocardiography at the same recording session to examine how echocardiographic AV is correlated with magnetocardiographic PR intervals at different gestational ages. In addition, they investigated the predictive value of AV interval for PR interval and the neonatal outcomes of fetuses with prolonged AV and PR intervals with the goal of developing criteria for fetal 1° AVB. They identified 39 controls and 31 cases who underwent 46 and 36 simultaneous fMCG and echo sessions, respectively; there were 109 controls and 9 cases who underwent fMCG only. The diagnostic threshold for 1° AV block was defined by z-scores and was identified to be GA-specific. A threshold of 3 z-score (AV interval: 158-173 ms) seemed appropriate with respect to the observed data. fMCG PR intervals could not be predicted with echo AV intervals.