Background: Most structural congenital heart defects can be identified prenatally through ultrasound examination in pregnancy or via routine examinations during hospital maternity stays, but in some cases, heart defects are not discovered prior to discharge. There has been little previous research into detection rates with the various methods available. In this study, we have examined the timing and method of diagnosis of severe congenital heart defects.
Material and method: All children with severe heart defects born in Norway in 2016 and registered at Oslo University Hospital were included in this study. In addition, information on committee-handled abortions (after the 12th week of pregnancy) was obtained from the Medical Birth Registry of Norway.
Results: In total, 105 of 181 (58 %) severe heart defects were diagnosed prenatally, and 51 (28 %) pregnancies were terminated. Among the 73 live-born children with severe heart defects that went unrecognised prenatally, 33 (45 %) of the heart defects were discovered outside of routine examinations and 9 (12 %) after discharge from hospital. Coarctation of the aorta was the most common diagnosis in cases of late-detected heart defects.
Interpretation: This first national study of the diagnosis of severe congenital heart defects in Norway shows that most severe congenital heart defects are discovered prior to discharge from hospital after birth. However, almost half are diagnosed outside of routine examinations, and in some cases the diagnosis is not made until after discharge. The results indicate a need for new studies and for a quality registry of congenital heart defects to further improve diagnosis and early treatment.