Evaluation of Myocardial Performance Index in Cases of Fetal Anemia: A Prospective Study

. Fetal anemia is a relatively rare but serious condition. An immune-related cause is most common, involving red-blood-cell (RBC) alloimmunization, followed by non-immune causes, such as parvovirus B19 infection and, more rarely, hemoglobinopathies, fetomaternal hemorrhage (FMH) and monochorionic twin complications, among others. Several advances have been made in the diagnosis and treatment of fetal anemia. High-resolution ultrasound now permits accurate, non-invasive screening by measurement of the middle cerebral artery peak systolic velocity (MCA-PSV) replacing serial amniocenteses for fetal anemia screening.

Severe fetal anemia may be associated with progressive loss of adaptive mechanisms because of inadequate tissue oxygenation. Ultimately, metabolic changes result in fetal acidosis and increased perinatal morbidity and mortality. Although cardiac decompensation does not seem to be the principal mechanism involved in the development of overt fetal hydrops, severe anemia may lead to cardiac ischemia, reduced contractility, and dysfunction.

Myocardial performance index (MPI) is a noninvasive technique that evaluates systolic and diastolic cardiac function by pulsed Doppler. Fetal MPI evaluation was originally described by Tsutsumi et al., and several studies have subsequently shown that it is a simple and reproducible technique. Significant changes in fetal MPI have been demonstrated in twin-twin transfusion syndrome recipient fetuses, intrauterine growth restriction, diabetes, and fetal inflammatory response syndrome The introduction of intrauterine transfusion (IUT) has dramatically improved survival, particularly in cases of red cell alloimmunization and parvovirus B19 infection.

However, access to IUT is limited in many low- and middle-income settings. In such environments, clinicians rely primarily on non-invasive diagnostic tools, particularly middle cerebral artery peak systolic velocity (MCA-PSV) Doppler assessment.