Evaluation of Right Myocardial Performance Index of In Vitro Fertilization Fetuses and Spontaneous Pregnancy Fetuses: A Cross-Sectional Study

OBJECTIVETo establish normal reference range for the fetal right myocardial performance index (RMPI), and compare the reference range between in vitro fertilization (IVF) fetuses and spontaneous pregnancy (SP) fetuses by automatic measurement of the RMPI.METHODSFrom September 2019 to January 2020, 410 participants, who were at 19-40 weeks' gestation, were enrolled into the current study. Among 410 participants, there were 371 spontaneous pregnancies which were matched as control group, and the experimental group involved 39 singleton pregnancies conceived by IVF. RMPI was calculated as (a-b)/b. The three readings were obtained and averaged per examination, with intra-observer repeatability assessed by intraclass correlation coefficient (ICC) and 95% confidence interval (CI). The ‘a’ and ‘b’ intervals were measured at 3 different caliper positions in each fetus: beginning of the original valve clicks (‘original’), beginning of the reflected tricuspid and pulmonary closure clicks (‘reflected’), and peak of valve clicks (‘peak’).RESULTSThe RMPI of SP fetuses was 0.43±0.05 (mean ± standard deviation (SD)), and the RMPI of IVF fetuses was 0.42 ±0.05 (mean ± SD). There was no significant difference in normal reference range of right MPI between IVF fetuses and SP fetuses. No strong correlation was also noted between RMPI with gestational age and heart rate.CONCLUSIONNormal reference ranges of RMPI of IVF fetuses and SP fetuses were established, and no significant difference between IVF fetuses and SP fetuses was found.