Fig. 2.

21 weeks 4 days ultrasound scan of Case 1.

a) The profile view in case 1 showed an absent nasal bone. There is no echogenic nasal bone below the echogenic skin line (arrow); b) Cranial halos can be better recognized but cerebral structures (arrows) of the nearfield could be easily identified, suggesting hypo-mineralized cranium; c) Sagittal view of vertebrae. Compared with the thoracic vertebrae, the vertebrae of the lumbosacral segment are smaller and farther apart, especially the L1 vertebrae (arrows), suggesting poor ossification; d) 3D skeletal views show small, irregularly lumbosacral and coccygeal vertebrae, especially the L1 vertebrae (arrows); e-f) long-axis view of left and right tibia and fibula showed congenital bowing.