[Osteogenesis imperfecta - diagnostic challenges]

Osteogenesis imperfecta (OI) is one of the commonest skeletal disorders with an incidence about one in 10,000. It is characterized by clinical and genetic heterogeneity. Congenital lethal OI (OI type II) is the most severe from with a possibility of the early prenatal sonographic diagnosis. The authors present two clinical cases of antenatal diagnosis of OI in 26 and 24 weeks of gestation. The pregnancies were terminated. The accurate specific diagnosis was based on the clinical examination and radiographic features. In case N 2 additional findings were ascites and hydrothorax, that may occasionally be found in literature. The accurate prenatal sonographic diagnosis of lethal skeletal dysplasias and particularly of OI is possible and based on the specific sonographic findings during the second trimester of pregnancy. Ultrasound screening of all pregnant women in early second trimester is an efficient method for detection of many fetal malformations. It requires a participation of the both clinician sonographer and geneticist in a team in order to achieve a specific genetic diagnosis.