OC016: Signs of decreased cardiac performance in anti‐Ro52/SSA antibody exposed fetuses with prolonged atrioventricular time intervals

Abstract

Objectives: Myocardial strain measures fractional change in ventricular wall dimension and allows quantification of myocardial performance. Quintero scoring for twin-twin transfusion syndrome (TTTS) cannot predict those who progress rapidly from stage 1 to intrauterine demise. We used vector-velocity imaging (VVI) which tracks natural myocardial speckles to calculate ventricular strain and determine whether this might aid risk stratification. Methods: We captured VVI images at about 100 Hz from a four chamber view during routine fetal echocardiograms in a pilot study of uncomplicated monochorionic twin pregnancies (MCDA) and ones with TTTS. Ventricular strain was calculated off-line and compared with our singleton reference range. Results: 33 MCDA pregnancies were studied at gestational age 21 + 5 (13 + 3 to 32 + 2) weeks. 20 pregnancies had TTTS (stages 1 = 3; 2 = 1; 3 = 12, 4 = 4) and 13 were uncomplicated. 40/66 scans (61%) were suitable for analysis and compared with reference data from 80 aged matched normal singleton pregnancies. Intra-class correlation was 0.68. Strain did not alter with gestational age and was normal in MCDA twins. Strain was significantly reduced in both recipient ventricles at stages 3 and 4, with a tendency to lower values in donor right ventricles. Reduced strain reflects ventricular response to increased afterload and possibly associated placental factors. Conclusions: As ventricular strain was normal in Quintero stages 1 and 2 it is unlikely to aid early risk stratification in MCDA pregnancies. Previously unreported abnormalities of right ventricular function may exist in the donor and require further investigation.