Progression to first-degree heart block in preschool children exposed in utero to maternal anti-SSA/Ro52 autoantibodies

Aims: To study the children exposed in utero to maternal anti‐SSA/Ro52 antibodies in terms of impaired atrioventricular (AV) conduction or disturbed myocardial performance, and to investigate the ability of prenatal Doppler to predict conduction abnormalities during childhood. Methods: Fifty‐seven children exposed in utero to anti‐SSA/Ro52 antibodies were grouped in accordance with (A) prolonged AV time intervals in utero by Doppler or (B) normal findings and examined by ECG, 24‐hour ECG and echocardiography. Results: PR interval on ECG was longer in group A (n = 16) compared with that of group B (n = 41), 140 ± 24 ms vs. 121 ± 13 ms (p < 0.01). Six cases of 1°Atrioventricular block (AVB) developed in group A, giving an estimated prevalence of 10.5%, (95% confidence interval; 4.4–22.2%), progressing from normal sinus rhythm at 1 month of age. Prenatal Doppler predicted development of 1°AVB at follow‐up with a sensitivity of 100%, Positive predictive value (PPV) 37.5%, LR+ 5.1, and Negative predictive value (NPV) 100%. Children in group A had a slightly higher myocardial performance index in flow and tissue Doppler imaging recordings. Conclusions: Ten per cent of children exposed in utero to anti‐SSA/Ro52, with a normal ECG at birth or 1 month of age, progressed to 1°AVB during preschool years. Cases at risk can be identified by prenatal Doppler echocardiography.