What is Cell-Free DNA Screening?
Prenatal cell-free DNA (cfDNA) screening test is performed using cell-free DNA analysis. The sample is obtained by a simple blood test. Cell-free DNA screening is an option for further screening of Down syndrome (Trisomy* 21), Edwards syndrome (Trisomy 18) and Patau syndrome (Trisomy 13). Fetal sex determination is also offered with this screen. The results have very low rates of false negatives (<1%) and false positives (<1%), reducing the risk of fetal loss due to invasive procedures.
*Trisomy means that there are three copies of a particular chromosome instead of the normal two copies. Example; trisomy 21 means that there are three copies of chromosome 21.
Prenatal Cell-Free DNA Screening Facts
· Reliability up to 99.9%
· Quick results (within 7 days)
· Screening from the 10th week of pregnancy
· Covered by the majority of group insurance
· Approved by Health Canada
What will the screening results tell me?
Results come back as ‘screen negative’ (very low chance that the baby has a chromosome difference for 13,18,21) or ‘screen positive’ (very likely chance that the baby has a chromosome difference but should be confirmed with invasive testing). There is less than a 5% chance of an inconclusive result.
Additional options
Presence of Y
This will detect the presence (or absence) of the Y Chromosome. Normally, each human cell has a pair of sex chromosomes. Male cells contain one Y and one X chromosome, while female cells contain two X chromosomes.
Sex Chromosome Aneuploidies
This will detect the number of sex chromosomes present. Most people have either two X chromosomes or one X and one Y chromosome in their cells. People with a sex chromosome aneuploidy ( SCA) have a different number of X and/or Y chromosomes. SCA that can be detected include Turner syndrome (X), Jacob’s syndrome (XXY), Klinefelter’s syndrome (XXY) and Triple X (XXX). People with SCA’s can have birth defects, infertility and learning differences. Some people with an SCA have such subtle features that the condition is not identified until after childhood.
When will my results be available?
Results are available within 7 days from the date of the blood draw. You will be notified via a secured email of the results. Our nursing team is available to answer questions you may have at the time of your appointment as well as after your results become available.
Is this screening covered by Alberta Health?
Cell-free DNA screening is currently not covered by Alberta Health - this is a patient-pay screening. Payment is collected at the time of the appointment by debit or credit card. An insurance letter and receipt will be provided if you wish to submit a claim to your extended benefits provider.
How do I book an appointment?
If you are interested in this screening, please request a requisition from your physician for ‘cell-free DNA screening’ and then call 403-289-9269 ext 1 to book your appointment for the blood draw anytime after 10 weeks of pregnancy.