Myocardial performance index in fetuses with small-for-gestational age in pregnancy: a systematic review and meta-analysis

Abstract

Background: The clinical utility and consistency of fetal Myocardial Performance Index (MPI) in assessing small for gestational age (SGA) remains contentious. Therefore, this study aimed to systematically evaluate the association between fetal MPI and SGA, and to assess the predictive value of MPI for adverse perinatal outcomes. Methods: PubMed, EMBASE, Web of Science, and The Cochrane Library were searched up to January 13, 2025. Studies comparing fetal MPI in singleton SGA pregnancies with healthy controls were included. Reviews, case reports, and studies without a control group were excluded. Data extraction followed PRISMA guidelines, and the protocol was prospectively registered with PROSPERO (CRD42023482293). Pooled estimates were generated using random-effects models for MPI and fixed-effects models for adverse perinatal outcomes. Subgroup, sensitivity, and meta-regression analyses were conducted. Results: 35 studies were included in the systematic review, with 27 eligible for meta-analysis. Fetuses with SGA had a significantly higher mean left fetal MPI compared to controls (WMD, 0.09; 95% CI, 0.06–0.11; I²=97%, P < 0.001). Subgroup analysis according to the classification of SGA revealed significant subgroup differences (P < 0.01), which remained consistent across SGA subtypes. No marked differences were found in gestational age at ultrasound and echocardiography technique. Elevated MPI was associated with an increased risk of adverse perinatal outcomes (OR, 3.71; 95% CI, 2.49–5.52; I²=0%, P < 0.001). Conclusions: This meta-analysis demonstrates that fetal MPI is significantly elevated in SGA pregnancies, indicating impaired global ventricular function. An increased MPI is associated with a higher risk of adverse perinatal outcomes. These findings support the potential utility of MPI as a tool for monitoring and risk stratification in SGA pregnancies. Clinical trial number: Not applicable.