Rittey L, Davidson H, Hornberger LK, Eckersley L, Boehme C, McBrien A.
J Am Soc Echocardiogr. 2024 Dec;37(12):1123-1132.e2. doi: 10.1016/j.echo.2024.08.012.
Commentary by:
Dr. Jared Hershenson (Greater Washington DC), section editor of Fetal Cardiology Journal Watch:
Take-home Points:
- Early fetal echo (EFE) allows for accurate diagnosis with limited false positives and negatives of most fetal cardiac disease
- Most fetuses with fetal cardiac disease diagnosed on EFE have a genetic diagnosis
- Serial EFE improves diagnostic ability, but venous anatomy and branch pulmonary artery visualization remains challenging
Prenatal diagnosis of critical congenital heart disease (CHD) significantly improves morbidity. Fetal echocardiography is typically performed after 16 weeks but many indications for fetal echo are present from the beginning or earlier in the pregnancy. Earlier imaging can allow for earlier decision making and earlier genetic testing (via CVS). However, there has been limited data on transabdominal fetal echo from 10-15 weeks.
This was a single center retrospective review of EFE. All patients were routinely encouraged to have a repeat fetal echo after 18 weeks. If EFE was inadequate, endovaginal or repeat EFE 1-2 weeks later were offered. EFE reports were reviewed and classified as normal, abnormal, or insufficient (minimum included a 4-chamber view, 2 great arteries, and their relationship). These were compared to follow up fetal echo reports (>18 weeks) or autopsy results to determine accuracy of EFE. If there were any differences, the team determined whether they were minor (no change in management) or significant. In those who had serial EFE, a points graded scoring tool was used to objectively assess each scan.
1621 fetuses had EFE; 1491 were normal. See Table 2. 89% of those had a later fetal echo. In that cohort, 97.1% had no structural heart disease detected, but 2.8% (38) did have fetal cardiac disease (FCD). 14 of those had structural CHD, and only 3/14 had major/significant CHD. The other 24 patients had progressive disease (arrhythmias and valvular lesions).
There were 130 fetuses with FCD diagnosed on EFE, the majority being ventricular or great artery disproportion (e.g., suspected L heart obstruction/coarctation), and single ventricle. Of the 130, only 39 (30%) had follow up. 35 of those were confirmed on later studies and 4 were considered “resolved”. In those that were confirmed, only 1 had a major discrepancy. For detecting major CHD, sensitivity of EFE was 92.9%, specificity 100%, PPV 100%, NPV 99.7%. In those who had multiple EFEs and mid-trimester studies, there was an improved image score in the later studies, primarily with better demonstration of venous anatomy and branch pulmonary arteries. 85% of patients with FCD had genetic testing, with a majority (71%) having abnormal results. See Table 4.
A limitation of this study was a low number of anatomic confirmations of FCD from EFE due to the relatively high rate of termination of pregnancy and fetal loss. However, this study shows that in experienced hands, EFE is not only feasible but likely quite accurate and can positively impact early prenatal care.
