Association between maternal autoimmune connective tissue disease and cardiac structure and function in the newborn

Introduction Newborns of mothers with autoimmune systemic connective tissue disease (CTD) have a higher incidence of major congenital heart defects (CHDs) compared to unexposed newborns. Less is known about the association between maternal CTD and less severe cardiac abnormalities in the newborn. Methods We analysed prospectively collected echocardiographic data from the Copenhagen Baby Heart Study (CBHS), comparing newborns exposed to maternal CTD with those who were not exposed. Maternal autoimmune CTD diagnoses were identified through the National Patient Register and validated by medical record review. Outcome measures included minor CHDs (atrial and ventricular septal defects, bicuspid aorta valve and patent ductus arteriosus), as well as cardiac dimensions and function. Results In total 25,590 newborns underwent echocardiography in the CBHS, of whom 57 (0.22%) were born to mothers with CTD. When comparing newborns of mothers with overall CTD to non-exposed newborns, we found no differences in structural and functional cardiac parameters. Minor CHDs were more common in newborns born to mothers with Sjögren’s disease (n = 3, 33.3%) than in unexposed newborns (n = 1,945, 7.6%, p = 0.03). Conclusions In this large population-based study, we did not observe consistent associations between overall maternal CTD and cardiac structure or function in the infant, although minor CHD were more common in newborns exposed to maternal Sjögren’s disease. Findings should be interpreted with caution, considering the small sample size of exposed newborns and potential underrepresentation of major CHD due to standard clinical management practices.