2082399 Fetal Myocardial Performance Index During Progression of Labor

The Myocardial Performance Index (MPI) is a Doppler derived myocardial function tool. It has been used in perinatology to evaluate systolic and diastolic dysfunction in fetuses with twin to twin transfusion syndrome and intrauterine growth restriction. The OBJECTIVES: of the study was to investigate the MPI during labor of normal term pregnancies, to establish normative values, and to evaluate change with cervical dilation. Women with uncomplicated, term, singleton pregnancies were recruited to this prospective observational study at Thomas Jefferson University Hospital. Exclusion criteria were multiples, fetal anomalies, preterm labor, non-cephalic presentation. Participants underwent an ultrasound examination by one sonographer, during which fetal left and right sided isovolumic contraction time (ICT), isovolumic relaxation time (IRT) and ejection time(ET) were recorded before, during and after contractions. Right and left sided MPI were then calculated using the formula MPI = (ICT+IRT)/ET. MPI was measured before, during and after uterine contractions. The MPI was calculated using an average of three measurements of ICT, IRT and ET. Statistical analysis was performed with student t-test, and X2 as appropriate. A p value of <0.05 was considered statistically significant. 20 patients were recruited. On average, patients were 29.2 ± 5.7 years old, in their 4th pregnancy, with a BMI of 32.9 ± 5.0 at delivery. The average left MPI during labor in term fetuses was 0.34 ± 0.04. The average right MPI during labor was 0.22 ± 0.07. There was no difference in Left or Right MPI based on contraction timing (p= 0.82, p= 0.80). The coefficient of correlation (R value) between MPI and cervical dilation was 0.15 for Left MPI Index and 0.09 for Right MPI. Myocardial Performance Index is a non-invasive, easily attainable measure of cardiac function that can be obtained during labor and does not change with labor. The fetal MPI may help define fetal status in labor.