Abnormalities in pregnancies with failures for noninvasive prenatal testing

In a study to be presented on Feb. 6 in an oral concurrent session at 1:15 p.m. PST, at the Society for Maternal-Fetal Medicine's annual meeting, The Pregnancy Meeting, in San Diego, researchers will report on the high rate of chromosomal abnormalities in patients in whom noninvasive prenatal testing fails to provide results.

Noninvasive prenatal testing has become popular with many physicians in screening pregnant patients. The study, titled Chromosomal Abnormalities Detected in Patients with Failure to Obtain Test Results Using Non-invasive Prenatal Testing, looked at noninvasive prenatal tests in a total of 4,446 pregnancies. The tests were performed from October 2012 to June 2104. High risk women were offered noninvasive prenatal tests per the American Congress of Obstetricians and Gynecologists guidelines and tests were done at an outside laboratory. Results were reported as "low risk", "high risk", or, if no result was obtained, as "redraw request." The incidence of chromosomal abnormalities in the RR group was compared to the entire cohort.

The study concluded that there is a high rate of chromosomal abnormalities in patients in whom NIPT fails to provide a result. Nearly half of tests will again fail on subsequent NIPT attempts.

"This is important information for patients and providers and requires clear understanding on how to interpret test results and appropriate follow up," explained John Turocy, M.D., one of the researchers of the study who is also presenting the findings at the SMFM annual meeting.