Treatment options for preventing autoimmune-mediated congenital heart block: a systematic review.

Objective: Complete congenital heart block (CHB) due to anti-Ro/La antibodies in pregnancy can lead to adverse fetal outcomes and neonatal death. National and international guidelines do not recommend specific treatment for women identified with anti-Ro antibodies while pregnant.

Design: Systematic review of studies of pregnant women with anti-Ro/La antibodies undertaking treatment(s) to prevent CHB. Studies solely focused on treating developing or established CHB were excluded.

Main outcome measure: CHB incidence.

Results: Of 1049 articles, 20 studies were eligible, of which 13 were retrospective. Sixteen studies contained usable data comparing various treatments (seven hydroxychloroquine (HCQ), six corticosteroids, two intravenous immunoglobulin (IVIG) and one each on combined HCQ and corticosteroids and plasmapheresis), including 2134 women and 2915 pregnancies. Meta-analysis was not possible due to heterogeneity. HCQ as primary prophylaxis showed protective effect on CHB incidence in four of five studies, whereas for preventing recurrence, only one study had a comparator arm, which showed a protective effect. Corticosteroids showed protective effect on CHB incidence as primary prophylaxis in two of three studies, whereas in recurrence, only one study showed protective effect. The IVIG study with a comparator showed no protective effect on CHB recurrence. Two studies (IVIG and plasmapheresis) had no comparator. The long-term toxicity of treatments was poorly investigated.

Conclusion: HCQ showed the most evidence among various treatment options to prevent CHB in babies of women with anti-Ro/La antibodies. However, included studies had high risk of bias and imprecision. Future studies should be prospective, compare existing treatments and capture adverse effects.PROSPERO registration number CRD42023492934.