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Is prenatal screening right for me?

It is your choice whether or not to have a prenatal screening test. There is not a right or wrong choice.

To help your decision-making, here are some questions expectant parents may ask themselves and discuss with a partner, health care provider, spiritual leader, family or friends.

1. Do I want to know the chance of my baby having Down syndrome, trisomy 18 or other chromosome difference?

2. What would I do with this information?


What could you do with this information:

Pregnancy management: If you are found to be at increased chance for one of these conditions, your health care provider may suggest additional tests (e.g. diagnostic testing, more ultrasounds) and/or suggest changes to how your pregnancy is managed or the way your baby is delivered

Reproductive choice: If I have a child with intellectual and/or physical disabilities, how might this affect my life, my other children, and my relationship with my partner and my extended family?  Some expectant parents have screening because they would like the information before birth to help with decision-making in the pregnancy.  If their baby was found to have one of these conditions they would:

  • prepare for a child with special needs
  • consider giving the baby up for adoption
  • consider stopping the pregnancy

Some expectant parents choose not to have screening because they would not:

  • have a diagnostic test under any circumstance because of the small chance of miscarriage
  • change the course of their pregnancy by choosing to end the pregnancy

Remember that most babies are born healthy, however 1 in 25 babies in Canada is born with a difference at birth requiring medical intervention (congenital anomaly).  Prenatal screening does not screen for all possible congenital anomalies. There is no cure for Down syndrome, trisomy 18 or other chromosome difference.

3. How will this information affect my feelings throughout the pregnancy?

A low chance (screen negative) result is the most common outcome and those expectant parents are likely to feel reassured.

Consider…how would I feel if I received an increased chance (screen positive) for one of these conditions? Many expectant parents experience anxiety and worry when their test results say that the chance of having a baby with one of these conditions is higher than expected.

4.  If your screening test result says there is an increased chance (screen positive) your baby has Down syndrome, trisomy 18 or other chromosome difference, you will need to decide if you want diagnostic testing. A screening test can only tell you the chance (probability) that your baby has one of these conditions. A diagnostic test can tell you for sure whether or not your baby does have the condition. Prenatal diagnostic testing for Down syndrome or trisomy 18 consists of amniocentesis or chorionic villus sampling (CVS).

Would I pursue diagnostic testing in the event of a screen positive result?


  • Diagnostic testing will tell you if your baby does or does not have one of these conditions, but with amniocentesis and chorionic villus sampling (CVS) procedures there is a small chance of miscarriage (1% or less).
    • Would I be willing to take that chance to have this information?
  • Diagnostic testing can also detect conditions for which you were not known to be at increased chance, such as another chromosome difference.
    • Would I want this additional information about my baby?
  • If diagnostic testing confirms a baby has the condition, expectant parents need to decide if they want to continue the pregnancy or if they will end the pregnancy.
    • If more testing shows that my baby has a condition for sure, what will I do with the information?

5. If you know that you would not end a pregnancy for any reason, prenatal screening may still be an option for you. With a prenatal diagnosis you can: plan for the birth of your child; find out from others what it is like to raise a child with this condition; learn about resources available in your community; meet with various health care teams who may be involved with your child’s care; or look into adoption.


  • Before the baby is born, to know for sure if a baby has one of these conditions, a diagnostic test like amniocentesis or chorionic villus sampling (CVS) is needed. Remember diagnostic tests are invasive and have a small chance of causing miscarriage.
  • Diagnostic testing for a chromosome difference can be performed on a blood sample once a baby is born. This is a non-invasive option for expectant parents who would not change the course of their pregnancy based on such a diagnosis
  • Would this information be helpful to me before the birth or can I wait until my baby is born?

Guide to understanding prenatal screening tests