Non-Invasive Chromosomal Evaluation of Trisomy Study

Inclusion Criteria:

- 1. Subject is at least 18 years old and can provide informed consent;

- 2. Subject has a viable singleton or twin pregnancy;

- 3. Subject is confirmed to be at least 10 weeks, 0 days gestation at the time of the
study blood draw;

- 4. Subject is planning to undergo CVS and/or amniocentesis for the purpose of genetic
analysis of the fetus OR the subject has already undergone CVS and/or amniocentesis
and is known to have a fetus with a chromosomal abnormality confirmed by genetic
analysis.

Exclusion Criteria:

- 1. Subject has known aneuploidy;

- 2. Subject is pregnant with more than two fetuses or has had sonographic evidence of
three or more gestational sacs at any time during pregnancy;

- 3. Subject has a fetal demise (including natural or elective reduction) identified
prior to consent;

- 4. Subject has history of malignancy treated with chemotherapy and/or major surgery,
or bone marrow transplant;