PEGASUS 1 - PROJECT COMPLETED

PEGASUS: PErsonalized Genomics for prenatal Aneuploidy Screening USing maternal blood

Each year, 450,000 Canadian women become pregnant and, as a result of their participation in prenatal screening for Down syndrome, approximately 10,000 of them will have an amniocentesis (i.e. sampling of liquid surrounding the fetus) and of those, 315 will be found to carry a baby with Down syndrome and 70 normal pregnancies will be lost from complications of the procedure. It has been discovered recently that, during pregnancy, there is fetal DNA in maternal blood in sufficient quantities to be analyzed and methods have been proposed to detect the presence of a fetus with Down syndrome using maternal blood. The introduction of genomic blood testing as proposed in the context of this project could lead to increased detection of Down syndrome, less invasive screening with 9,700 amniocenteses avoided each year in Canada, improving the peace of mind of pregnant women, and preventing the accidental loss of 70 normal fetuses, at a lower overall cost than current practice. However, these methods still need to be validated before being appropriately introduced in routine care. This project proposed to carry out an independent study that validated the performance and utility of these new genomic technologies for screening in pregnant women using maternal blood. The team of researchers identified an evidence-based cost-effective approach for implementation of this new technology in the Canadian health care system. They developed decision-making tools that assist couples in making informed decisions, as well as educational tools for health care professionals, all integral components of the implementation of genomics-based non-invasive prenatal diagnosis. The results of this project may enable decision makers–pregnant women and their partner–to make informed choices pertaining to prenatal genetic screening and diagnosis, such as screening for Down syndrome, and to reduce the risk to pregnancies associated with amniocentesis.