Long-term outcome of mothers of children with isolated heart block in Finland

Objective. To study the long-term outcome of mothers of children with isolated heart block in a defined population. Methods. We reviewed the Finnish hospital regis. tries for patients born between 1950 and 1999 who had been diagnosed as having isolated heart block before the age of 15 years. We identified 101 children with isolated congenital heart block (CHB) and 55 with isolated heart block detected after the newborn period. Eighty-three (91%) of the 91 mothers of children with CHB and 48 (87%) of the 55 mothers of children with heart block detected after the newborn period were studied according to a protocol defining clinical characteristics (mean 9.9 years, range 0-49 years, and mean 22.9 years, range 4-47 years after the index delivery, respectively). Maternal survival was compared with survival in an age-matched population of normal Finnish women. Results. Before the index delivery, 29 (37%) of the 78 surviving mothers of children with CHB had a self-reported clinical diagnosis of a chronic autoimmune disease, and 55 (71%) had had symptoms, signs, or abnormal laboratory findings suggesting an underlying subclinical disease. Of the 23 mothers who were completely asymptomatic before the index delivery, 10 (13% of the surviving mothers) remained so after a mean followup of 9.6 years (range 0-21 years). In mothers of children with CHB, clinical characteristics different from those of healthy mothers were photosensitivity, fatigue, dry eyes, and dry mouth. Forty-eight (58%) of these 83 mothers developed an autoimmune disease during followup. The most common diagnosis was primary Sjogren's syndrome (22 definite, 11 probable), followed by systemic lupus erythematosus (SLE). The standardized mortality ratio of mothers of children with CHB was 5.1, and 3 of the 5 deaths were associated with SLE. Mothers of children with heart block detected after the newborn period had similar symptoms and signs of autoimmune diseases as the healthy controls, and their standardized mortality ratio was 1.9. Conclusion. Primary Sjogren's syndrome, either definite or subclinical, is the predominant autoimmune disorder in mothers of children with CHB. Mothers of children with isolated heart block detected after the newborn period do not, as a group, have clinical features suggestive of autoimmune diseases.