Why are congenital heart defects being missed?

Area of Science:

• Medical imaging
• Fetal medicine
• Cardiology

Background:

• Congenital heart defects (CHD) are frequently missed during prenatal screening, leading to significant morbidity and mortality.
• Prenatal diagnosis of CHD is crucial for timely intervention and improved outcomes.

Purpose of the Study:

• To evaluate fetal heart image quality during the second-trimester standard anomaly scan (SAS).
• To identify factors associated with missed prenatal diagnoses of congenital heart defects (CHD).

Main Methods:

• A case-control study analyzed 114 fetuses with isolated severe CHD.
• Cardiac views (4CV, 3V, LVOT, RVOT) were scored for technical correctness by blinded experts.
• Regression analysis assessed the impact of sonographer and screening center experience on image quality.

Main Results:

• 50.9% of severe CHD cases were missed on SAS.
• Missed cases had significantly lower cardiac examination quality scores and reduced use of magnification.
• Poor adaptational skills (49%) and unrecognized abnormalities (31%) contributed to missed diagnoses.
• Higher volume of SAS per sonographer correlated with better examination quality.

Conclusions:

• Sonographer adaptational skills, not circumstantial factors, are key in prenatal CHD detection.
• Inadequate image quality and failure to recognize abnormalities are major reasons for missed diagnoses.
• Increased experience and higher screening volumes in ultrasound centers improve prenatal CHD detection rates.