Changes in fetal myocardial performance index following intravascular transfusion: preliminary report.

OBJECTIVE: To investigate the changes in fetal left ventricle myocardial performance index (MPI) following intrauterine intravascular transfusion (IUT). METHODS: Prospective study, including 25 IUT performed in 13 singleton pregnancies with maternal Rh D alloimmune disease. Left ventricle MPI was evaluated prior to transfusion and repeated 24 h after each procedure. Delta MPI was calculated as the difference between post- and pre-transfusion MPI z-scores. Multilevel regression analysis was used to examine the association between delta MPI and gestational age at procedure, fetal middle cerebral artery peak velocity MoM, pre- and post-MPI and hemoglobin z-score values, the volume of blood transfused and feto-placental volume percentage expansion. Adjustments were made for repeated measurements within the same fetus, and across different time points. The significance level was set as 0.05. RESULTS: MPI z-score values increased significantly following transfusion (delta MPI = 1.10 ± 2.47, p=0.036). Delta MPI showed a significant correlation with gestational age at transfusion (r= -0.47, p=0.018), pre-transfusion MPI z-score (r= -0.50, p=0.012) and feto-placental volume percentage expansion (r= -0.41, p=0.044). CONCLUSION: Left ventricle MPI increases significantly after intrauterine blood transfusion and greater changes are associated with procedures at an earlier gestational age, lower pre-transfusion MPI z-scores and smaller feto-placental volume expansion.

Myocardial performance index in fetal anemia.

OBJECTIVE: The objective of the study was to examine the correlation between fetal myocardial performance index (MPI) and hemoglobin (Hb) levels. METHODS: It is a prospective study involving singleton pregnancies at risk of fetal anemia as a result of maternal anti-D alloimmune disease. Right and left ventricle (LV) MPIs were evaluated by ultrasound up to 72 h before cordocentesis. Zeta-score values for fetal MPI and Hb levels were calculated, and correlation was examined with linear regression analysis. Significance level was set as 0.05. RESULTS: Fourteen singleton pregnancies underwent 31 cordocentesis procedures at a mean gestation of 28.2 ± 4.1 weeks. Zeta-score values for LV MPI, isovolumetric relaxation time (IRT), and ejection time (ET) correlated significantly with fetal Hb zeta-score (LV MPI zeta = 3.816 + 0.336 × Hb zeta, r = 0.59, p < 0.001; LV IRT zeta = 2.643 + 0.218 × Hb zeta, r = 0.45, p = 0.01; LV ET zeta = -2.474 - 0.271 × Hb zeta, r = -0.42, p = 0.02). LV isovolumetric contraction time (ICT) zeta-score and right ventricle (RV) MPI did not show significant correlation (LV ICT zeta, r = 0.35, p = 0.054; RV MPI, r = 0.12, p = 0.53). CONCLUSION: LV myocardial performance not only remains preserved but also is actually enhanced in cases of moderate/severe fetal anemia.