A further case of confined placental mosaicism for trisomy 2 associated with adverse pregnancy outcome

Objectives To add to the knowledge base concerning confined placental mosaicism for trisomy 2. Methods Cytogenetic study of a late CVS referred for hyperechogenic bowel and raised AFP, and cytogenetic and molecular genetic study of a follow‐up amniocentesis. Ultrasound monitoring at regular intervals following the CVS result. Results All cells examined from direct and cultured CVS showed a 47,XY,+2 karyotype. Amniocentesis showed a mosaic 47,XY,+2[8]/46,XY[81] karyotype. Uniparental disomy (UPD) studies on the amniotic fluid showed normal biparental inheritance. The pregnancy developed oligohydramnios and IUGR and resulted in a 26‐week liveborn male infant with a 46,XY karyotype, which died after 3 days because of complications of severe prematurity. Placental villi post delivery showed only the 47,XY,+2 cell line. Conclusions This case represents a further example of confined placental mosaicism (CPM) for trisomy 2 associated with oligohydramnios, IUGR and poor pregnancy outcome. Copyright © 2003 John Wiley & Sons, Ltd.