Renal artery pulsatility index and myocardial performance index are not related with adverse perinatal outcome in late onset fetal growth restriction

This study aimed to compare uncomplicated pregnancies and pregnancies complicated by late-onset fetal growth restriction (FGR) in terms of myocardial performance index (MPI) and renal artery pulsatility index (PI), and to explore whether these parameters are associated with adverse perinatal outcomes. This prospective case–control study included 46 uncomplicated pregnancies and 51 pregnancies with late-onset fetal growth restriction. A composite adverse perinatal outcome was defined by the presence of stillbirth, neonatal death, any Apgar score < 7, need for neonatal resuscitation, umbilical cord pH < 7.1, or admission to the neonatal intensive care unit. Renal artery PI and MPI values did not differ significantly between pregnancies with late-onset FGR and uncomplicated pregnancies. In the entire cohort, a weak positive correlation was observed between renal artery PI and umbilical cord pH (r = 0.206, p = 0.044), while MPI was negatively correlated with birthweight (r = − 0.340, p = 0.001). Exploratory receiver operating characteristic analyses demonstrated limited discriminative performance of both renal artery PI and MPI for adverse perinatal outcomes. Renal artery PI and MPI do not appear to have sufficient predictive value for adverse perinatal outcomes in late-onset FGR. Although MPI was higher in pregnancies complicated by late-onset FGR and showed an association with birthweight, its clinical utility as a standalone diagnostic parameter appears limited.