An efficient protocol for the detection of chromosomal abnormalities in spontaneous miscarriages or foetal deaths
Received 25 November 2008; received in revised form 25 June 2009; accepted 31 July 2009. published online 01 September 2009.
Abstract
Objective
Characterization of chromosomal abnormalities in 232 spontaneous miscarriages or foetal deaths using both classical and molecular cytogenetics.
Study design
Chromosomal abnormalities are responsible for 40–50% of all early pregnancy losses. Conventional cytogenetics is associated with 10–40% of culture failure. Comparative genomic hybridization (CGH) is a DNA-based technique that screens chromosome imbalances in the whole genome and may overcome this problem, although additional methods are required to distinguish between different ploidies, mosaicisms and maternal cell contamination. For a full characterization of chromosomal aberrations in 232 spontaneous miscarriages or foetal deaths we applied a sequential protocol that uses conventional cytogenetics, plus CGH and touch fluorescence in situ hybridization (Touch FISH).
Results
Successful karyotyping was obtained in 173/232 (74.6%) of the cases, 66/173 (38.2%) of which had an abnormal chromosomal complement. CGH and Touch FISH analyses revealed another 19 abnormal cases in the 63 failures of culture. Overall there were 85/233 (36.6%) cases with an abnormal chromosomal complement, with examples from all three trimesters. Comparing cases, with or without chromosomal abnormalities, no statistical differences were found between women with one or recurrent miscarriages. On the contrary, significant differences were found comparing mean maternal ages or mean gestational ages, in cases with or without chromosomes abnormalities.
Conclusion
Adopting this sequential protocol, chromosomal complement information was available even in cases with culture failure.
aDepartment of Genetics, Faculty of Medicine, University of Porto, Porto, Portugal
bDepartment of Obstetrics and Gynecology, Hospital São João, Faculty of Medicine, University of Porto, Porto, Portugal
cDepartment of Pathology, Hospital São João, Porto, Portugal
dLab. Cell Biology, Institute of Biomedical Sciences Abel Salazar, University of Porto, Porto, Portugal
Corresponding author at: Department of Genetics, Faculty of Medicine, University of Porto, Alameda Prof. Hernâni Monteiro, 4200-319 Porto, Portugal. Tel.: +351 22 5513647; fax: +351 22 5513648.
ABSTRACT