Supplementary Material for: Use of the Myocardial Performance Index in Decreased Fetal Movement Assessment: A Case-Control Study

Objectives: To determine whether there are any fetal cardiac function changes, as measured by the myocardial performance index (MPI), in pregnancies complicated by decreased fetal movement (DFM). Methods: We performed a prospective cross-sectional case-control study of 50 DFM and 50 uncomplicated third-trimester pregnancies matched within 2 gestational weeks. Routine ultrasound growth and well-being parameters as well as MPI were measured. Average MPI measurements and its component values were compared between the DFM and the control group, as were demographics, other ultrasound data, and perinatal outcomes. Results: Average left MPI (LMPI) and right MPI (RMPI) was similar between groups (LMPI: 0.54 ± 0.08 [DFM], 0.53 ± 0.08 [controls], p = 0.76; RMPI: 0.60 ± 0.12 (DFM), 0.59 ± 0.11 [controls], p = 0.79). However, subgroup analysis of DFM fetuses with (n = 20) or without (n = 30) any adverse perinatal outcome demonstrated modestly higher average RMPI and LMPI in the adverse perinatal outcome group (RMPI: 0.64 ± 0.08 vs. 0.57 ± 0.13, p = 0.02; LMPI: 0.56 ± 0.07 vs. 0.52 ± 0.07, p = 0.052). Conclusion: The MPI did not demonstrate clinically usable differences between the overall DFM population and controls. However, higher LMPI and RMPI values in the exploratory subgroup of DFM fetuses with adverse perinatal outcomes may warrant further exploration of the MPI in DFM.