Diagnosis of major cardiac defects through routine early pregnancy ultrasound examination

Early detection of major cardiac defects is crucial for the management and prognosis of affected pregnancies. This study evaluated the effectiveness of routine first-trimester ultrasounds in detecting major cardiac defects in singleton pregnancies.

This retrospective study (2015-2023) at a tertiary center included 35,230 singleton pregnancies undergoing routine ultrasounds at 11-14, 20-24, 28-34, and 34-38 weeks. High-resolution equipment and standardized protocols were used to assess fetal nuchal translucency and cardiac structure.

Among the 35,230 pregnancies studied, 270 cases (0.8%) of major heart defects were identified. Hypoplastic left heart syndrome (HLHS) was detected in 31 cases with a 90% detection rate, while ventricular septal defects (VSD) were the most common, found in 128 cases with a lower detection rate of 16%. Pregnancy outcomes varied significantly with gestational age: 55.9% of early detections (11-13 weeks) led to termination, while 63.9% of mid-term detections (18-22 weeks) resulted in live births. The first-trimester ultrasound scans demonstrated 100% sensitivity and Negative Predictive Value (NPV), with a specificity of 93.85% and a Positive Predictive Value (PPV) of 90.27%. The Kappa value of 0.917 indicated moderate agreement between early and later scans. Notably, early diagnosis (11-13 weeks) was associated with a higher rate of pregnancy terminations, while later diagnoses corresponded to higher live birth rates.

Routine first-trimester ultrasounds effectively detect major cardiac defects early. However, the high sensitivity but low specificity necessitates follow-up scans to confirm findings and reduce false positives, ultimately enhancing prenatal care.