The study, which is expected to be published in a peer-reviewed medical journal soon, found that the new technique, microarray, surpassed standard testing in detecting chromosomal abnormalities that can cause problems like autism or mental retardation.
The new technique still requires fetal cells to be obtained either by amniocentesis, in which a long needle is stuck into the womb, or by another invasive procedure called chorionic villus sampling, in which tissue is taken from the placenta. But instead of then examining the fetal chromosomes under a microscope, a DNA-sensing chip is used to detect abnormalities too small to be seen.
A big concern, however, is that it is not always possible to tell whether a small abnormality detected by the chip will be harmful to a child, or if so, how severe such a problem will be. That can cause anxiety for expectant parents and make it difficult to decide whether to terminate a pregnancy.
View the original article here: New prenatal testing can detect more genetic problems