The prenatal ultrasonographic diagnosis of osteogenesis imperfecta lethalis.

The ultrasonographic features of osteogenesis imperfecta lethalis (OI Type II), including those not reported previously (*), are: In the skull: *Abnormal compressibility of the vault by the transducer, which may alter measurements of biparietal diameter. *Unusually good visualization of the orbits. *Increased visualization of arterial pulsations. *Increased through-transmission of the ultra-sound beam due to extremely poor mineralization. In the remainder of the skeleton. *Diminished visualization and increased through-transmission of the remainder of the skeleton, particularly of the spine, ribs and long bones due to defective mineralization. *Abnormally short limbs and poor visualization of the long bones due to defective mineralization. *Abnormally small thorax due to collapse of the rib cage. *Reduced fetal movement. Recognition of fetal fractures and deformities. Prenatal radiographs can be used to confirm the diagnosis and differentiate between osteogenesis imperfecta lethalis and other forms of neonatal dwarfism.