Objectives: To evaluate the potential value of early fetal echocardiography (EFE) by means of four-dimensional (4D) spatiotemporal image correlation (STIC) technology for either reassurance of normality or prenatal diagnosis of major congenital heart defects (CHDs).
Methods: Sixty-nine pregnant women from 11 to 15 weeks' gestation underwent EFE. 4D-STIC volumes were acquired by the transvaginal approach for later review by two different examiners. STIC evaluation was considered complete when the four-chamber view, and the origin and double-crossing of the great arteries were identified correctly. Color Doppler imaging was used to detect either septal shunts or transvalvular regurgitation/aliasing suggesting abnormalities. STIC diagnoses were compared with those of conventional EFE. Reliability was assessed by postnatal examination, or autopsy in cases of termination of pregnancy or perinatal death.
Results: The median gestational age at volume acquisition was 13 + 3 weeks. Eleven (15.9%) cases of CHD were diagnosed. A complete EFE was possible in 64 cases. We were able to provide reassurance of normality in 51 of the 53 confirmed normal hearts, with no false-positive results for major defects, although two minor defects (one ventricular septal defect (VSD) and one persistent left superior vena cava) were falsely suspected. The only false negative was a significant VSD at birth overlooked by both observers. Therefore, the total accuracy of STIC-EFE was 95.3% (61/64), with sensitivity, specificity, and positive and negative predictive values of 90.9%, 96.2%, 83.3% and 98.1%. The accuracy of conventional EFE (98.4%, 63/64) was slightly better than that of STIC, with no false-positive results recorded.
Conclusions: Offline evaluation of 4D-STIC acquired volumes of the fetal heart in the first and early second trimester of pregnancy is reliable not only for early reassurance of normal cardiac anatomy but also to diagnose most major structural heart defects.
(c) 2009 ISUOG.