[Lethal osteogenesis imperfecta: antenatal diagnosis].

Osteogenesis imperfecta (OI) is a heterogeneous group of diseases affecting type I collagen and characterized by bone fragility. Lethal forms are rare and are characterized by micromelia associated with limb deformities. We report two cases of prenatally diagnosed lethal OI. Patients underwent ultrasound examination at 17 and 25 weeks of amenorrhoea, supplemented with fetal skeletal CT scanning in one case. Therapeutic abortion was recommended in both cases.