Prenatal Genetic Screening and Ultrasound

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Prenatal Genetic Screening

Prenatal genetic screening can tell you the chance of your baby having trisomy 21 (Down syndrome) or trisomy 18 (Edwards syndrome), two genetic conditions that cause intellectual disability and health problems. The screening does not tell you if the baby has either condition, only if there is a high or low chance that it might. It takes another test to be sure the baby has either condition.

Prenatal genetic screening is available to all pregnant people in Ontario. Your options for testing will depend on how far along you are in the pregnancy, how many babies you are carrying, availability in your area, and other aspects. It is important that you are aware of the benefits and limitations of the available tests, to help you make a choice that is right for you.

You may consider talking to your pregnancy care provider about being referred to the nearest genetics centre if you have further questions about your prenatal genetic screening results or if you have concerns about your medical history or family health history.

Here are some useful websites to help you understand prenatal genetic screening, and when to consider seeing a specialist at a genetics centre.

Ultrasound

You can consider having ultrasounds in pregnancy even if you do not wish to have prenatal genetic screening. These ultrasounds will give you valuable information such as: how far along your pregnancy is, how many babies you are carrying, and whether there are concerns with the baby's growth and anatomy.

Having an ultrasound involves lying down and having a doctor or ultrasound technologist examine your uterus (either through your abdomen or vagina) using a hand-held probe covered in transmission gel. The ultrasound probe (also called a transducer) creates an image of your uterus and the baby, by picking up sound waves that travel through your skin, that the ultrasound operator can see on a computer screen.

The links below have more information about what to expect from your ultrasound and concerns related to non-medical use of ultrasound.