The purpose of this study is to collect samples for the purpose of developing a prenatal aneuploid test using circulating cell free fetal (ccff) nucleic acid from blood samples from pregnant women who have a high-risk pregnancy undergoing invasive prenatal diagnosis by chorionic villus sampling (CVS) and/or genetic amniocentesis. The results of the ccff aneuploid test will be compared to the chromosomal analysis obtained via CVS or amniocentesis.

Inclusion Criteria:

• Subject is female
• Subject is pregnant
• Subject is 18 years of age or older
• Subject provides a signed and dated informed consent
• Subject agrees to provide a 30-50mL blood sample
• Subject is at increased risk for Down syndrome or other aneuploidies (greater than or equal to 35 years of age at time of delivery, elevated risk by maternal serum markers including Triple, Quad and integrated test, fetal birth defects or markers identified by ultrasound or family history of aneuploidy).
• Subject plans to undergo an amniocentesis and/or CVS procedure
• Subject agrees that the FISH, karyotype, and/or QF-PCR results obtained via the invasive procedure will be provided

Exclusion Criteria:

• None

Pregnant women who are scheduled to undergo a CVS or amniocentesis procedure and will receive the FISH, karyotype and/or QF-PCR results from the procedure.