Serial echocardiography for immune‐mediated heart disease in the fetus: results of a risk‐based prospective surveillance strategy

OBJECTIVE: Mothers carrying anti-Ro antibodies are frequently referred for weekly echocardiograms to early detect and treat antibody-mediated fetal heart disease. We tested a surveillance strategy based on anti-Ro antibody titers. METHODS: From 2009 to 2014, 232 pregnancies were referred for maternal anti-Ro antibodies. At the baseline echocardiogram, anti-Ro titers were measured by enzyme-linked immunosorbent essay and results categorized as negative (<8 U/mL; n = 43; excluded), low-moderate positive (8-49 U/mL; n = 62; group 1) or high positive (50 - >100 U/mL; n = 127; group 2). Serial echocardiograms to ≥24 weeks were only recommended for group 2 mothers. RESULTS: Group 1 patients underwent significantly less fetal echocardiograms when compared with group 2 mothers (median 2 vs. 4; p < 0.001). Isolated endocardial fibroelastosis (n = 1) and incomplete (n = 4) or complete (n = 4) heart block were diagnosed in 9 (8%) pregnancies with anti-Ro titers >100 U/mL but none with lower titers (odds ratio 17.78; p = 0.004). Incomplete block and endocardial fibroelastosis regressed with transplacental corticosteroid and immune globulin therapy. CONCLUSIONS: Limiting serial fetal echocardiograms to women with high anti-Ro antibody levels is safe and more cost effective. While numbers of echocardiograms were significantly reduced in referrals with anti-Ro titers <50 U/mL, reversible abnormalities with prenatal treatment were detected by serial echocardiography in group 2 patients.