Assignment task: SCREENING
Prenatal screening for fetal aneuploidy is a rapidly changing field, and there are variations in screening protocols both provincially and regionally. Clinicians should be aware of the availability of and protocols for screening in their geographical area. Biochemical and ultrasound screening tests are now available during pregnancy to assess the risk of having a fetus with trisomy 21. If the risk of trisomy 21 is higher than a specified risk cut-off as determined by the screening program, a diagnostic test (e.g., amniocentesis) is offered to confirm or exclude the presence of trisomy 21 (and some other chromosome abnormalities).