A processor identifies a first set of characteristic models of a structure in cross-plane images acquired at a first acquisition period. The processor identifies a second set of characteristic models of the structure in cross-plane images acquired at a second subsequent acquisition period. The processor determines an amount of rotation of the structure based at least in part on a difference in shape of the first set of characteristic models and the second set of characteristic models. The system and method may include determining a labor progress based at least in part on the determined amount of rotation of the structure. The structure may be a fetal head. The cross-plane images acquired at the first acquisition period may be acquired simultaneously by a single ultrasound device. The cross-plane images acquired at the second subsequent acquisition period may be acquired simultaneously by a single ultrasound device.