key: cord-0828147-xweh962v
authors: Cardinal, Mikhail-Paul; Poder, Thomas G.; Roy-Lacroix, Marie-Eve; Cavallé-Garrido, Tiscar; Vaujois, Laurence; Dallaire, Frédéric
title: Considerations for scaling down fetal echocardiograms during the COVID-19 pandemic
date: 2020-04-21
journal: Can J Cardiol
DOI: 10.1016/j.cjca.2020.04.016
sha: e1804b495fcf86e663907c4c185ca2d4145fd239
doc_id: 828147
cord_uid: xweh962v

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In the context of the COVID-19 pandemic, institutions performing fetal echocardiograms (FE) are weighing the risks and benefits of reducing the number of FE to free up resources and limit nonessential visits to hospitals and clinics. These decisions must be made rapidly, often without a solid knowledge base. As of the first week of April 2020, strategies adopted by Canadian institutions varied considerably, with some significantly scaling down the number of FE and others maintaining the pace as before the pandemic. Here, we wish to bring forth preliminary results of the FREQUENCY study, a population-based retrospective cohort built to assess the performance of prenatal congenital heart disease (CHD) screening in Quebec. 1 Although these results are preliminary, 2 they show that scaling down the number of FE when the 2 nd trimester ultrasound is normal can be done without a significant increased in undetected severe CHDs.

The full protocol was previously published. 1 Briefly, we merged data from all FE performed in Quebec between 2007 and 2015 with administrative healthcare data of all mother-child dyads in Quebec during the same period. The cohort included 698,984 pregnancies. Of them, 14,917 (2.1%) were referred for a FE for fetal or maternal risk factors despite a normal 2 nd trimester ultrasound, in accordance to the scientific statement of the American Heart Association. 3 We defined moderate to severe CHD as CHD prompting termination of pregnancy, requiring cardiac intervention or causing death <12 months of age (excluding isolated septal defects). We also present results for severe CHD requiring intervention < 1 month of life. The Table details the number needed to screen according to the FE indication. When the 2 nd trimester ultrasound was normal, the number needed to screen was 222 for moderate to severe CHD, and 361 for severe CHD. We estimate that in the presence of a normal 2 nd trimester ultrasound, not performing FE for maternal diabetes, family history of CHD, maternal medication, and increased nuchal moderate to severe CHD occurred in pregnancies without risk factors and were thus not referred for a FE. From the perspective of the overall population of Quebec, not performing a FE when the 2 nd trimester ultrasound in normal would increase the overall number of undetected significant CHD by <0.8 per 10,000 pregnancies.

The COVID-19 pandemic situation is ever changing and varies amongst institutions. The purpose of this letter is not to advocate for reducing the number of FE, but to provide evidence that, if it becomes temporarily necessary, it could be done rapidly for patients with a normal 2 nd trimester scan without increasing the number of missed severe CHD. In a non-pandemic situation, balancing the pros and cons of fetal cardiology referrals is more complex. Such balancing should include CHD specific detection rates, both FE and obstetrical ultrasound sensitivities and specificities, regional variations in detection rates, and cost-benefit analysis, all of which will be addressed in the final analyses of our study.

Rationale and Design of the FREQUENCY Study: The Fetal Cardiac Registry of Quebec to Improve Resource Utilization in Fetal Cardiology

FREQUENCY: Very low yeild of fetal echocardiography in high risk pregnancies with a normal obstetrical second trimester ultrasound. ACC.20 Together With World Congress of Cardiology

Diagnosis and treatment of fetal cardiac disease: a scientific statement from the

CHD: congenital heart disease, FE: fetal echocardiography *These FE were referred for high risk pregnancies but were performed before the 2 nd trimester scan for various logistical reasons. These were excluded from the analysis as he results of the FE were known to the physicians performing the 2 nd trimester scan.