Impact of Cell-Free Fetal DNA Screening on Patients' Choice of Invasive Procedures after a Positive California Prenatal Screen Result.

Forum Shah,Maureen Bocian,Lauren Korty,Marilyn Jones,Kathryn French,Kathryn Osann

doi:10.3390/jcm3030849

Abstract

Until recently, maternal serum analyte levels paired with sonographic fetal nuchal translucency measurement was the most accurate prenatal screen available for Trisomies 18 and 21, (91% and 94% detection and false positive rates of 0.31% and 4.5% respectively). Women with positive California Prenatal Screening Program (CPSP) results have the option of diagnostic testing to determine definitively if the fetus has a chromosomal abnormality. Cell-free fetal (cff-) DNA screening for Trisomies 13, 18, and 21 was first offered in 2012, allowing women with positive screens to choose additional screening before diagnostic testing. Cff-DNA sensitivity rates are as high as 99.9% and 99.1%, with false positive rates of 0.4% and 0.1%, for Trisomies 18 and 21, respectively. A retrospective chart review was performed in 2012 on 500 CPSP referrals at the University of California, San Diego Thornton Hospital. Data were collected prior to and after the introduction of cff-DNA. There was a significant increase in the number of participants who chose to pursue additional testing and a decrease in the number of invasive procedures performed after cff-DNA screening was available. We conclude that as fetal aneuploidy screening improves, the number of invasive procedures will continue to decrease.

Highlights

This study focuses on women who have screened positive through the California Prenatal Screening Program (CPSP) and identifies the options women chose upon receiving these positive results
A total of five hundred participants were evaluated in this study: 250 participants in 2011 and 250 participants in 2012
Cohorts did not differ with respect to ethnicity, gestational trimester at positive screen, health insurance type, CPSP screening test, or reason for referral

Summary

Introduction

Since the introduction of second trimester screening designed to detect open neural tube defects (NTD) and ventral wall defects (VWD) in the fetus, screening programs have evolved and grown to include multiple genetic conditions, including Trisomy 18, Trisomy 21, and Smith-Lemli Opitz syndrome (SLOS) as well as NTD and VWD [1,2,3,4]. Prior to the introduction of prenatal screening, women only had the option of invasive testing (i.e., amniocentesis and chorionic villus sampling (CVS)) to determine if their fetuses were affected[11]. Both invasive procedures have an accuracy of nearly 100% [11,12,13].

Methods

Results

Conclusion