Benefits of and variability within a nationwide CHD screening programme.

Abstract

Approximately 0.8% of all pregnancies are complicated by congenital heart disease (CDH) (Zhao et al. J Pediatr 2019;204:53–8). Prenatal diagnosis of CHD has been shown to reduce neonatal morbidity when compared with postnatal diagnosis, and significant efforts have been made by experts and leading professional societies to educate sonographers in optimal cardiac imaging techniques (Friedberg et al. J Pediatr 2009;155:26–31, ISUOG Practice Guideline, Ultrasound Obstet Gynecol 2013;41:348–59). Despite such efforts, many CHD cases are still undetected during prenatal ultrasound exams. In this issue, Dr Hautala and colleagues review, analyse, and present outcome data from a nation-wide prenatal CHD screening programme in Finland between 2004 and 2014. A total of 642 456 ongoing and 3449 terminated pregnancies with severe fetal anomalies were analysed (Hautala et al. BJOG 2019; 126:864–73). CHD detection rates were compared between three time periods: prescreening period, transition period, and screening period. To address possible confounders, the incidences of maternal risk factors were evaluated during the time periods between mothers with and without a prenatal diagnosis. The prenatal detection rate of univentricular cardiac anomalies (UVH) increased from 50.4 to 82.8% between the prescreening and screening periods, and transposition of the great arteries (TGA) from 12.3 to 41.3% (P < 0.0001); significant regional differences in detection rates were observed within the country. Maternal obesity, in vitro fertilisation, pre-gestational diabetes and smoking did not affect prenatal detection rates. This manuscript contributes to the existing literature for several reasons. While the authors note similar reports from the Czech Republic and the Netherlands, robust data from nation-wide cohorts are rare. Approximately 95% of pregnant women in Finland participate in ultrasound screening during pregnancy, and the authors were able to assess differences by region. The authors studied whether changes in potential risk factors led to the increase in detection as a means of identifying the true benefit of the screening programme. In addition, they were able to determine whether the diagnosis was made within or outside the screening programme. It is also important to note the manuscript's limitations. First, the generalisability of the findings may be limited as the exams were performed by midwives rather than physicians. The authors note that an expert committee recommended the programme include ongoing auditing of screening personnel, but it is unclear what this audit includes and to what extent it was implemented during the study period. From a technical perspective, the authors studied the benefit of the 4-chamber cardiac view and cardiac outflow tract views, but do not account for more recent recommendations to incorporate the 3-vessel cardiac view, particularly for the detection of TGA. Hopefully, future analyses can determine the added yield of incorporating this important CHD screening view. Finally, the authors were not able to determine the reason behind differences in detection by region. Improving prenatal detection of all fetal anomalies and particularly CHD is an endeavour of paramount importance. In contrast to the existing literature, which is laden with single institution reports and expert commentary highlighting the role of tertiary care settings and expert sonography in improving the prenatal detection of CHD, this manuscript illustrates significant benefit when nation-wide standardised programmes are instituted, even when midwives are the ones performing the exams. In an era when health economics play an important role in translation of science to the bedside, the findings of this manuscript should garner even closer attention. None declared. A completed disclosure of interests form is available to view online as supporting information. Please note: The publisher is not responsible for the content or functionality of any supporting information supplied by the authors. Any queries (other than missing content) should be directed to the corresponding author for the article.