CAGC-ACCG

Your doctor will offer screening for various conditions during your pregnancy. This screening will include a combination of a blood test, mother’s age at delivery and possibly an ultrasound. All of this information helps evaluate the chance that the pregnancy may have Down Syndrome (Trisomy 21).  A positive (or high risk) result means your pregnancy is at an increased risk for Trisomy 21. This does not mean that the baby definitely has Trisomy 21. Most people who test positive on screening will not have a baby with Trisomy 21. However, your positive screen means that there is a higher chance that this may happen and therefore you are eligible for some additional testing if you wish to clarify if this is the case or not. Talk to your family doctor, obstetrician, or midwife about next steps, such as follow-up testing or a referral to a genetic counsellor.

At this time, the government cannot fund Non-Invasive Prenatal Testing (NIPT) for all pregnant women due to the cost. Screening for Down syndrome in pregnancy through tests such as maternal serum screening with or without ultrasound is available to all pregnant women, and additional testing may be offered to those ​​identified to be at an increased risk, based on provincial guidelines. You can speak to your health care provider to determine if you are eligible.

Your genetic counsellor will ask you questions about your pregnancy, as well as your family history. They will review genetic concepts, and review information about the reason you were referred (e.g., a positive screen, an ultrasound finding, or a family history of a genetic condition). You will be offered appropriate testing, if applicable, and you will be supported throughout the process. In some areas, follow up is done by a team of clinicians and nurses.

We can test pregnancies for chromosome conditions, such as Down syndrome. Additionally, we can test a pregnancy for specific genetic conditions if there is a known diagnosis in the family, and that person has had genetic testing. Other conditions would not be tested for in pregnancy unless there was a reason to arrange this testing. For example, if there were specific ultrasound findings. Some diagnoses, such as autism, typically do not have a clear genetic cause, and therefore cannot be checked for in a pregnancy. Targeted genetic testing in a pregnancy is done through an amniocentesis or chorionic villus sampling (CVS).

To meet with a genetic counsellor there must be an increased risk for a genetic condition compared to the general population. Some reasons to see a genetic counsellor include family history of a genetic condition, biological parents are carriers of genetic conditions, ultrasound findings, including some soft markers, or high-risk prenatal screening results.