Prenatal sonographic diagnosis of skeletal dysplasias. A report of 47 cases

The purpose of this study was to evaluate the foetal sonographic efficiency for prenatal diagnosis of osteochondrodysplasias. Forty-seven prenatal and postnatal cases diagnosed between January 1993 and December 1998 in the re ferral sonographic centres of Strasbourg were studied. All cases were revie wed retrospectively and the prenatal ultrasound findings and diagnosis were compared to the postnatal or post-mortem diagnosis. Each case was studied by ultrasonographers, geneticists, radiologists, and foetopathologists. Fin al diagnosis was based on clinical examination, skeletal survey and molecul ar testing as deemed necessary. Routine screening and dating was the indica tion for foetal sonography in 72 % (32/47) of our cases. The most likely ti me of diagnosis was between 16 and 24 weeks of gestation (17 out of 47 case s, 36 %), which corresponds to the time of foetal anomaly sonographic scan in France. The other cluster of cases (12 among 47, 26 %) was disclosed bef ore 16 weeks of gestation. These results illustrate the importance of a det ailed evaluation of the limbs during sonographic examinations of first and second trimesters of pregnancy. While the identification of skeletal dyspla sias was relatively easy in our study, the ability to make an accurate spec ific antenatal diagnosis was more difficult. An accurate diagnosis was prop osed in 28 of the 47 cases (60 %). In 19 % of the cases (9/47), the prenata l diagnosis was not accurate; in 21 % of the cases (10/47), the prenatal di agnosis was imprecise. In 45 of the 47 cases (96 %) prenatal foetal scan co rrectly predicted the prognosis. (C) 2000 Editions scientifiques et medical es Elsevier SAS.