Prevalence and significance of isolated fetal choroid plexus cysts detected in early pregnancy by transvaginal sonography in women of advanced maternal age

This study examines the prevalence of isolated fetal choroid plexus cysts ( CPCs) detected in early pregnancy by transvaginal sonography in an increase d genetic risk population and their association with abnormal fetal karyoty pe. A prospective study was performed on 1692 pregnant women (>37 years) wh o underwent transvaginal scan at 11-16 weeks' gestation before genetic amni ocentesis. The prevalence of isolated CPCs in our population was 1.48 per c ent. An abnormal fetal karyotype was found in one case (4 per cent). It was concluded that if fetal CPCs are apparently isolated, genetic amniocentesi s is not mandatory and additional risk factors such as advanced maternal ag e should be the main indication for fetal karyotyping. Copyright (C) 1999 J ohn Wiley & Sons, Ltd.