REDWOOD CITY, Calif., Feb. 15, 2013 /PRNewswire/ -- Verinata Health, Inc., a privately-held company dedicated to maternal and fetal health, today presented data demonstrating its approach to detect aneuploidies in maternal blood from multiple gestation pregnancies.
Contrary to previous study findings by other investigators, this study demonstrated that each fetus in twin pregnancies contributes approximately 50 percent less cell-free fetal DNA to a maternal blood sample when compared to the cell-free DNA makeup of singleton pregnancies. As a result of this reduced fetal fraction, deeper sequencing is necessary to determine if a chromosome abnormality is or is not present in one or both of the fetuses with a high degree of confidence.
"While we were able to correctly detect aneuploidy in twin pregnancies with a sequencing depth similar to that currently implemented for singleton pregnancies, deeper sequencing offers better resolution and discrimination for these complex samples," said Richard Rava, Ph.D., Chief Scientific Officer of Verinata Health. "Thus, it may reduce the number of false negatives and increase the confidence in the results for multiple gestation pregnancies."
The analysis included 85 maternal plasma samples that were previously excluded from Verinata's large, blinded, prospective validation study of singleton pregnancies. The full singleton study results were previously published in the peer-reviewed journal, Obstetrics & Gynecology (Green Journal). The results show that Verinata's technology correctly detected the one incidence of Down syndrome (trisomy 21) and one incidence of Edwards syndrome (trisomy 18) present within this study population. Importantly, the study also demonstrated that 10 to 15 percent of cases may be at risk of having inadequate fetal cfDNA for accurate classification. Verinata's unique approach using deeper sequencing is required to provide confidence that aneuploidies will be correctly identified.
The study results were presented in an oral presentation entitled "Maternal Plasma DNA Sequencing: Effects of Multiple Gestation on Aneuploidy Detection and the Relative Cell-Free Fetal DNA (cffDNA) per Fetus," (Oral Concurrent Session 4, Program ID#52). Diana Bianchi, M.D. of the Mother Infant Research Institute at Tufts Medical Center presented the data at the 33rd Annual Meeting of the Society for Maternal-Fetal Medicine on February 15, 2013 at 3:15 p.m. Pacific Time.
Verinata Health, Inc.
Verinata is driven by a sole, extraordinary purpose maternal and fetal health. Our initial focus is to develop and offer non-invasive tests for early identification of fetal chromosomal abnormalities using our proprietary technologies. We aim to reduce the anxiety associated with today's multi-step process, the unacceptable false-positive rates, the non-specific and sometimes confusing results of current prenatal screening methods, as well as the risk of current invasive procedures. We support national guidelines and the recent American College of Obstetricians and Gynecologists and the Society for Maternal-Fetal Medicine Committee Opinion recommending cell-free DNA prenatal testing is one option that can be used as a primary or secondary screening test in women at increased risk of aneuploidy. We believe women who desire such testing should be offered a single blood draw test with a definitive result. The verifi® prenatal test is available through a physician. For more information about Verinata, please go to www.verinata.com.
SOURCE Verinata Health