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

• enhanced First Trimester Screening: A screen positive result for trisomy 21 means that the chance that your pregnancy has trisomy 21 is higher than 1 in 350. 
• Maternal Serum Screening: A screen positive result for trisomy 21 means that the chance that your pregnancy has trisomy 21 is higher than 1 in 200. Please note that during the COVID-19 pandemic, the threshold has been temporarily moved to 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. Only invasive diagnostic testing (chorionic villus sampling or amniocentesis) can tell you for sure if your baby has trisomy 21 or trisomy 18.