Fig. 2
Reasons for referral for prospective study specimens. The reasons for referral were collected by the genetic counselor or geneticist at the time of study enrolment and reported on the specimen requisition. Totals do not add up to 100% because some patients had multiple reasons for referral. Positive biochemical screen, a maternal serum screening result (first trimester, second trimester, or integrated prenatal screen) with a risk > 1 in 200 for a chromosome abnormality; AMA, advanced maternal age defined as 35 years or older at the time of delivery; U/S abn, ultrasound abnormality; other: other reasons for referral, including family history of a chromosome or single gene disorder, previous child affected with a chromosome or single gene disorder, and maternal anxiety.
