Positive Results
Your enhanced first trimester screening (eFTS) or maternal serum screening (MSS) screen result was reported as a positive screen result.
A positive screen result
- means that there is a higher chance for your baby to have one of the conditions screened for. This is based on the fact that your estimated chance is above the accepted screening cut-off.
- does not mean that your baby definitely has trisomy 21 (Down syndrome) or trisomy 18. In fact, most of the time that there is a positive screen for one of these conditions, the baby does not turn out to have the condition. For example, if the estimated chance on your report is 1 in 100 you can think of it as a 1% chance that the baby has trisomy 21 (and 99% chance that the baby does not have trisomy 21)
Screening cut-offs
A screen positive result for trisomy 21 means that the chance that your pregnancy has trisomy 21 is higher than 1 in 350.
False positive results
Because screening tests are not 100% accurate, most individuals who get a positive screen result will go on to have a baby without the condition.
Next steps
If you have a positive screen result, you should be offered further testing options by your pregnancy care provider, and/or a referral for genetic counselling. You now have the option of a more accurate screening test (NIPT), and would be covered by OHIP in your situation. You also have the option of diagnostic testing (chorionic villus sampling or amniocentesis), or to not do any further testing. Only diagnostic testing can tell you for sure if your baby has trisomy 21 or trisomy 18.