We read with interest the original article by Wren et al about the trends in diagnosis of major congenital cardiovascular malformations published in the fetal and neonatal issue of the journal.1 The paper discusses the difficulties that we are still experiencing in diagnosing the cardiovascular (CVS) abnormalities. It is evident that we continue to miss life-threatening abnormalities despite efforts to improve our detection rates.

The authors in their discussion suggest that better early diagnosis of serious congenital cardiac malformations is likely to be achieved by further improvements in antenatal diagnosis and more wide-spread use of routine pulse oximetry. Whether this is indeed the case is open to debate.

Firstly, how can we realistically improve the antenatal detection rate? The current practice …