Obstet Gynecol. 2014 May;123 Suppl 1:100S. doi: 10.1097/01.AOG.0000447444.73608.82.
Noninvasive prenatal testing compared with invasive diagnostic testing in the setting of an abnormal state aneuploidy screen.
To describe the abnormal results of invasive prenatal diagnostic testing performed for the indication of positive state aneuploidy screening at our institution and to further identify among those results the genetic abnormalities that would not have been detected by noninvasive (cell-free fetal DNA) prenatal testing.
This was a retrospective review of all patients that underwent invasive prenatal genetic testing (chorionic villus sampling, amniocentesis, or both) for the indication of positive state aneuploidy screening from June 2012 to June 2013 at a single, large academic medical center. Abnormal results were identified. Abnormalities that would not be detected by noninvasive cell- free DNA testing were further noted.
There were 84 chorionic villus sampling and 38 amniocentesis procedures (total n=122) performed for the indication of positive state aneuploidy screening during this period. No karyotypic abnormality was detected in 89 (73%). Abnormalities detected included: 22 (18%) trisomy 21, three (2%) trisomy 18, two (2%) 45, X, and two (2%) 47, XYY. The remaining two were abnormalities that are not detected by current commercially available noninvasive tests: a balanced translocation and a loss of an oligonucleotide on the X chromosome.
Most patients undergoing invasive testing for positive state screen results had aneuploidies that would have been detectable by current available noninvasive tests. However, some of the abnormalities would not have been identified by noninvasive prenatal testing. These limitations should be taken into account when counseling patients who test positive on state prenatal screening programs. Larger studies are needed to validate these findings.
- [PubMed - in process]