Subject is female

Subject is 18 years or older

Subject is no less than 8 and no more than 36 weeks gestation

Subject provides a signed and dated informed consent

Subject agrees to provide one or more 30-50mL blood sample(s) in accordance with the protocol

Subject has a current pregnancy in which the fetus is known to have chromosomal aneuploidy (e.g. T13, T18, T21)

Noninvasive Screening for Affected Pregnancies: Assay Development & Optimization in Affected Pregnancies