CGH in the detection of confined placental mosaicism (CPM) in placentas of abnormal pregnancies

Comparative genomic hybridization (CGH) was applied to samples taken from various sites of placentas originating from complicated pregnancies: 24 with intrauterine growth restriction (IUGR), one with multiple fetal malformation, one with toxemia, one with hydrocephalus and two with undetectable maternal serum alpha-fetoprotein (MSAFP). One of the most common aberrations in the IUGR cases was the addition of a whole or part of the X chromosome. Other aberrations such as additional Y chromosome or of 13(q22) or loss of chromosome 17 also appeared in different cases. In one IUGR case trisomy 8 (in one site) and 47,XXY (in all sites) were detected. In the two cases with undetectable MSAFP monosomy 16 was found. Some of the results were also confirmed by the FISH technique. In all the control cases (six normal and five with aneuploidy) CGH concurred with the known karyotype. Our results demonstrate the usefulness of the CGH technique in the genetic evaluation of fresh and paraffin embedded placentas in problematic pregnancies even when morphology is normal. However, it is very important to take multiple samples from different sites of the placenta. Copyright © 2002 John Wiley & Sons, Ltd.