Reference range of fetal lung volume by 3D-ultrasonography using the rotational method (VOCAL).

Aim: To determine reference ranges for fetal lung volume by 3-dimensional ultrasonography using the VOCAL (Virtual Organ Computed-aided Analysis) method.

Methods: A longitudinal prospective study was conducted with 61 uncomplicated pregnancies between 24 and 32 weeks of gestation. A separate measurement of both lungs volume was conducted by VOCAL with 30 degrees rotation angle.