VARIABLE PRENATAL APPEARANCE OF OSTEOGENESIS IMPERFECTA

Osteogenesis imperfecta is a heterogeneous group of disorders of type I collagen with both lethal and nonlethal forms. Prenatal sonographic findings in affected fetuses are variable and depend on the severity o f the disease. Six cases of osteogenesis imperfecta in which prenatal sonography had been performed were reviewed. Two cases of lethal type II osteogenesis imperfecta revealed short femurs at 16 to 17 weeks' ge station with development of bowing and fractures by 19 weeks' gestatio n. Four fetuses with the nonlethal type III or IV had femoral bowing w ith or without shortening in the late second or third trimester with g rossly normal mineralization. Fractures in this latter group did not d evelop until 1 to 12 months after delivery. Understanding the progress ive nature and variability of osteogenesis imperfecta is crucial in th e prenatal diagnosis and management of this disease.