SPECKLE TRACKING ECHOCARDIOGRAPHY IN TWIN PREGNANCIES AND THE ROLE OF GLOBAL LONGITUDINAL STRAIN AND PEAK SYSTOLIC STRAIN: A SYSTEMATIC REVIEW AND META-ANALYSIS.

Twin pregnancies are associated with an increased risk of perinatal morbidity and mortality. Pregnancy complications related to twins, such as fetal growth restriction, and twin-to-twin transfusion syndrome (TTTS), are associated with hemodynamic changes in the fetal heart. Two-dimensional speckle tracking echocardiography (2D STE) is a tool to evaluate fetal cardiac function. This paper aims to review the literature regarding global longitudinal strain (rate) and peak systolic strain (rate) assessed with 2D STE in twin pregnancies. Feasibility, frame rate, and angle of the fetal heart at the time of measurement were selected as secondary outcomes. The databases Medline, Embase, Scopus, and Web of Science were searched. Seven articles met the inclusion criteria and selected all monochorionic diamniotic (MCDA) twins with TTTS as the study population. The global longitudinal strain in the right and left ventricle and the peak systolic strain in the right ventricle of the recipient MCDA twin is significantly decreased compared to the donor MCDA twin. 2D STE assessment was shown feasible and reproducible in MCDA pregnancies. Large heterogeneity in technical characteristics between the articles induces inconsistent results. Although feasible, the knowledge of 2D STE is very limited in twin pregnancy. Prospective studies are needed to evaluate the 2D STE assessment in uncomplicated twin pregnancies considering its possible additive value in the diagnostics of pregnancy-related pathologies.