Boehme C, Fruitman D, Eckersley L, Low R, Bennett J, McBrien A, Alvarez S, Pastuck M, Hornberger LK.J Am Soc Echocardiogr. 2022 Feb;35(2):217-227.e1. doi: 10.1016/j.echo.2021.09.005. Epub 2021 Sep 13.PMID: 34530071
Take Home Points
- Suspected fetal CHD carries the highest yield for diagnosis of CHD by fetal echocardiography followed by suspected or confirmed genetic disorder
- Maternal history of diabetes and family history of CHD provide a low yield for diagnosis of fetal CHD
- The presence of multiple risk factors increases the yield of fetal echocardiography
Commentary from Dr. Anna Tsirka (Hartford, CT, USA), section editor of Pediatric and Fetal Cardiology Journal Watch
This is a retrospective cross sectional study investigating the yield of current indications for fetal echocardiography (FE) in the province of Alberta, Canada. In Canada >99% of pregnancies undergo fetal anatomic ultrasound and those with risk for fetal anomalies or suspicion of anomalies on routine screening are referred for fetal echocardiography to 2 institutions, in Edmonton and Calgary.
The study period included all referrals to those two centers between January 2009 and December 2018.Indications for referral were those aligned with the ASE and AHA recommendations.Outcomes were categorized as shown in the table below:
During that decadestudied, 19218 pregnancies were referred for FE in a population with about 53000 births/year.
The number of referrals increased over the time period with the biggest increase in referrals for maternal diabetes (+5.6%) and multiple gestation (+3.1%). As the number of referrals increased, the number of diagnosis of FHD also increased, both for moderate to severe and mild or suspected FHD, as shown below:
Referrals for extracardiac markers represented about 30% of referrals, for maternal diabetes 18.3%, suspected FHD and family history of CHD 17.7% each, and multiple gestation for 5.1%.
Referrals for suspected FHD yielded the highest percentage of moderate or severe FHD at 41% (with another 9.9% with mild or suspected FHD), followed by extracardiac pathology or markers, multiple gestation and genetic disorders. These indications accounted for 91.4% of all cases of moderate or severe CHD, while suspected FHD disease alone represented 73% of diagnoses of moderate to severe FHD! The lowest yielding indications for referral were family history of CHD (1.7%) and maternal diabetes (2.2%).
40.8% of patients referred for suspected arrhythmia were diagnosed with arrhythmias, but the majority (55%) represented premature atrial contractions.
Referral for multiple gestation yielded moderate or severe FHD in 10.6% of cases, if one includes TTTS in the category, or 3.9% if one excludes TTTS.
80% of referrals for suspected FHD did not have a second indication for referral. For referrals for more than 2 indications other than suspected FHD, there was an increase in the yield of FHD compared to single indication (see figure below
This is the largest study so far evaluating indications for referral for FE and their yield. It confirms prior reports that suspicion of FHD on obstetric screening followed by extracardiac markers such as genetic conditions are the biggest indicators of the presence of FHD.
An isolated finding of a single umbilical cord had a low yield for the presence of FHD (1.8%), however this increased to over 10% with the presence of an additional risk factor.
These findings indicate the importance of fetal cardiac screening during the anatomy ultrasound in low risk pregnancies and the need for continued education of obstetricians who perform screening ultrasounds.