Application of free-hand three-dimensional echocardiography in the evaluation of fetal cardiac ejection fraction: a preliminary study.

Objective: To investigate the feasibility of using free-hand three-dimensional (3D) echocardiography to evaluate fetal cardiac function.

Methods: 3D cardiac data were collected during screening examinations for 37 normal fetuses with gestational ages of between 16 and 26 weeks. Processing of the 3D volumes included separation of the end-diastolic and end-systolic slices, segmentation of right and left ventricles, measurement of end-diastolic and end-systolic volumes, and calculation of the ejection fraction (EF) for each ventricle. In 21 fetuses at 21-24 weeks, right and left ventricle volumes and EF were compared.

Results: Twenty-five cases were appropriate for final statistical analysis. The volume of the ventricles increased with gestational age and estimated fetal weight. There was no significant trend in the difference between the volumes and EF of the right and left ventricles in the 21-24-week subgroup. The mean right and left ventricular EF were 54 +/- 11.2% and 57.5 +/- 14.6%, respectively. The mean combined EF of ventricles during gestation was 55.1 +/- 10.7% and seemed to remain constant during the gestational ages studied.

Conclusions: 3D echocardiography can provide estimates of ventricular volume and function and may in future be used for evaluation of fetuses with congenital heart disease and cardiac dysfunction.