By Pam Foy
Nearly 40,000 babies born in the U.S. each year suffer from congenital heart defects (CHD), with one in four infants in such critical condition that they require surgery shortly after birth, according to the Centers for Disease Control and Prevention (2022). CHD not only costs $5.6 billion in hospitalizations annually, but also severely impacts families in terms of added financial stress, increased caregiving time, and decreased mental health. To maximize the detection of CHD, all pregnant patients should receive a comprehensive ultrasound screening of the fetal heart.
Yet, detection rates for prenatal CHD have not improved significantly, with diagnostic ultrasound still failing to detect CHD in approximately half of cases (van Velzen et al., 2018). This lack of progress is particularly surprising when we consider that ultrasound technology has been used to diagnose fetal abnormalities since the 1950s.
Diagnostic ultrasound is an imaging modality that is operator dependent, which may explain the persistently low detection rates. Some sonographers and physicians simply struggle to conceptualize and understand the spatial relationships of a 3D heart model from a 2D image. Most sonographers and physicians know how to manipulate the scan plane of normal fetal hearts during ultrasounds, but manipulating the scan planes of an abnormal heart can be very different.
3D ultrasound was introduced in the 1980s. While the detail is greater in 3D images, the technique is just a succession of 2D scans on different planes brought together with image processing software. Next came 4D ultrasounds, which are essentially 3D scans with added motion. As history shows, 3D and 4D ultrasounds did not improve detection rates significantly.
Today, 5D ultrasounds offer a promising new approach to evaluate the fetal heart. The technology automatically creates nine fetal echocardiography views of the initially captured image to diagnose most cardiac defects. While 5D uses the same 3D transducer technology to capture images, it leverages AI technology to generate higher-resolution echocardiographic volumes of the heart. It’s why 5D ultrasounds are often referred to as “HD ultrasounds” commercially.
5D technology significantly enhances the clarity of a natal heart image. It sharpens organ features, improves depth perception, and adds a virtual light source to better differentiate shadows and reflections. Ultrasound practitioners can display all nine planes of an image simultaneously in a single template, improving the identification of complex intracardiac relationships and enabling them to navigate easily and consistently through the volume of the heart. The duration time of the ultrasound is typically shorter, allowing practitioners to develop more streamlined workflows.
Lastly, the accuracy and simplicity of conducting 5D ultrasounds can reduce operator dependency. That’s not to suggest it can replace human expertise. As with any new technology, education, training, experience, and assessment are essential to improving detection rates. The adage in sonography goes, “You see what you know. If you know a lot, you see a lot. But if you know very little, you see very little.” Therefore, manually navigating through the 5D volumes using software requires a comprehensive understanding of fetal cardiac anatomy.
To achieve higher detection rates with 5D ultrasound, obstetrical sonographers must establish comprehensive screening programs combined with professional training and certification. Well-trained, credentialed healthcare professionals are the best way to ensure that new parents and babies achieve the best outcomes.
Consider the Netherlands. The Dutch healthcare system enforces a national screening program combined with a strict national protocol in which every OB/GYN sonographer must undergo training and pass examination. Every two years, they are monitored and assessed for proficiency, and if their assessments lag, their credentials are withdrawn until they regain competency through additional training. The Netherlands’ screening program has resulted in one of the highest detection rates for prenatal CHD worldwide.
Since CHDs are a leading cause of birth defect–associated infant illness and death, an affected infant’s survival depends on when and, more importantly, how accurately CHD is diagnosed. 5D ultrasounds offer a significant leap forward in improving prenatal CHD detection rates that have been stuck in neutral for decades. But 5D technology will never obviate the need for highly trained and certified professionals to conduct screenings.
Pam Foy is imaging training program manager at The Ohio State University, and an Inteleos Volunteer.
Centers for Disease Control and Prevention (n.d.). Data and statistics on congenital heart defects. https://www.cdc.gov/ncbddd/heartdefects/data.html
van Velzen, C. L., Ket, J. C. F., van de Ven, P. M., Blom, N. A., & Haak, M. C. (2018). Systematic review and meta‐analysis of the performance of second‐trimester screening for prenatal detection of congenital heart defects. International Journal of Gynecology & Obstetrics, 140(2), 137–145. https://doi.org/10.1002/ijgo.12373