"DNA Sequencing versus Standard Prenatal Aneuploidy Screening"
NEJM
http://www.nejm.org/doi/full/10.1056/NEJMoa1311037?query=featured_home 
"CONCLUSIONS

In a general obstetrical population, prenatal testing with the use of cfDNA had significantly lower false positive rates and higher positive predictive values for detection of trisomies 21 and 18 than standard screening. (Funded by Illumina; ClinicalTrials.gov number,NCT01663350.)"