“…An increased IRT is generally accompanied by a reduced ET, with the ICT the most stable MPI parameter [4]. The MPI has been used to demonstrate fetal cardiac dysfunction in a number of pathologies including maternal diabetes [11,12,13,14,15,16], TTTS [7,17,18,19,20,21,22], congenital heart malformations [23,24,25,26,27,28], pre-eclampsia [29], IUGR [11,30,31,32,33,34], and other fetal conditions [35,36,37,38]. Several studies have proposed methods to improve the repeatability of fetal MPI by defining fixed machine settings [39] and using the clicks of the aortic and mitral valves as landmarks to delineate the constituent time intervals [9,40,41].…”