According to a study, a noninvasive, sequencing-based approach for detecting chromosomal abnormalities in the developing fetus is safer and more informative in some cases than traditional methods. The study was published by Cell Press on January 10th in The American Journal of Human Genetics. This method, which analyzes fetal DNA in the mother's blood, could provide women with a cost-effective way to find out whether their unborn baby will have major developmental problems without risking a miscarriage.
"Our study is the first to show that almost all the information that is available from an invasive procedure is also available noninvasively from a simple maternal blood draw," says senior study author Richard Rava of Verinata Health.
Metaphase karyotypes—pictures of chromosomes taken through the microscope—have traditionally been used to detect abnormalities associated with developmental delay, intellectual disability, congenital defects, and autism. Recently, a method called a chromosome microarray, which uses molecular probes to detect gains or losses of DNA segments within chromosomes, has been shown to provide more detailed information than a metaphase karyotype. But both of these approaches require invasive procedures that involve removing tissue from the placenta or inserting a needle into the amniotic sac to collect fluid. As a result, they increase the risk of infection and could harm the fetus during pregnancy.