Reference ranges of fetal spleen biometric parameters and volume assessed by three-dimensional ultrasound and their applicability in spleen malformations.

Aim: The aims of this article are to establish three-dimensional ultrasonographic nomograms of normal fetal spleen size and to evaluate the clinical application value.

Methods: An observational, cross-sectional study was performed on 455 women with a normal singleton pregnancy between 18 and 38 weeks' gestational age (GA). Fetal spleen volume was measured using three-dimensional ultrasound equipped with virtual organ computer-aided analysis, and biometric parameters were assessed in multiplanar mode to create reference ranges to GA. Thirty cases were randomly selected to conduct reliability analyses via intraobserver and interobserver ultrasonographic measurement. Moreover, 50 cases of suspected splenic malformations were evaluated by the newly established nomograms and followed up subsequently.

Results: Using regression formulas, we found that fetal spleen size increased with GA. We observed strong reliability in intraobserver and interobserver volume measurements with intraclass correlation coefficients of 0.994 and 0.962. Bland-Altman analyses showed narrow limits of agreement [intraobserver: (-3.2 to 3.5)%; interobserver: (-3.2 to 4.3)%]. Of the 50 cases with suspected splenic malformations, six cases of splenomegaly and one case of splenic cyst were diagnosed.

Conclusion: Three-dimensional ultrasound nomograms of normal fetal spleen size across a range of GA have a strong diagnostic value. Volume measurements with good reliability were optimal in clinical practice.