Reference values for the volumes of foetal heart atrial wall by three-dimensional ultrasound using STIC and VOCAL methods between 20w0d and 33w6d weeks of gestation

Abstract

Objective: To establish reference values for the volumes of foetal heart atrial wall by three-dimensional (3D) ultrasound using spatio-temporal image correlation (STIC) and virtual organ computer-aided analysis (VOCAL) methods.Methods: We performed a retrospective cross-sectional study with 170 normal singleton pregnancies between 20 weeks + 0 days (20w0d) and 33 weeks + 6 days (33w6d) of gestation. Foetal heart atrial wall volume was obtained by VOCAL method with 30-degree rotation (six planes) subtracting the internal volume from the atrium volume. Polynomial regression with adjustments by determination coefficient (R2) was performed. To calculate the interobserver reproducibility, concordance correlation coefficient (CCC) was applied.Results: The mean ± standard deviation (SD) for the left atrium wall volume (cm3) ranged from 0.54 ± 0.21 at 20w0d–20w6d to 2.17 ± 0.30 at 33w0d–33w6d. The mean ± SD for the right atrium wall volume (cm3) ranged from 0.45 ± 0.16 at 20w0d–20w6d to 2.17 ± 0.62 at 33w0d–33w6d. We observed a satisfactory interobserver reproducibility with CCC = 0.69 and 0.58 for the left and right volumes of foetal heart atrial wall, respectively. The best-fit models were first-degree: volume for the left atrium wall = −2.194 + 0.139*GA (R2 = 0.41) and volume for the right atrium wall = −2.757 + 0.155*GA (R2 = 0.37).Conclusion: Reference values for the volumes of foetal heart atrial wall by 3D ultrasound using STIC and VOCAL methods between 20w0d and 33w6d weeks of gestation were established.