Down’s Risk Profile: Interpretation of Trisomy 18 and Trisomy 13

Monday, 17 January 2022

TDL has been notified of a change in the reporting process for Down’s Risk Profile (DRP), effective 17th January 2022.

The Antenatal Screening Service at Barts and the London School of Medicine have explained that there is now a preference to report Trisomy 18 (T18) and Trisomy 13 (T13) as a single risk chance.

This single risk chance will be incorporated into their new report. Their risk/chance interpretation software has been adapted to incorporate the single risk/chance, together with their existing individual risk/chance for T18 and T13, given as a comment beneath the result interpretation.

An example of how this report might present is as shown below:

 

INTERPRETATION  
Screening result: Screen negative
Risk of Down’s: Less than 1 in 50,000 (at term)
Risk of Trisomy 18 or Trisomy 13: 1 in 8,000 (at term)
Comment: Risk of trisomy 18: 1 in 33,000 at term; trisomy 13: 1 in 11,000 at term
Comment: This test does not screen for neural tube defects
Comment: The risk estimate for Down’s syndrome takes account of MoMs in a previous pregnancy

 

There will be no change in the reporting time or the price.

TDL will continue to refer all Down’s Risk Screens to the Antenatal Screening Services at Barts and the London School of Medicine.

If you have any queries about this change of reporting, please contact Maulik Trivedi.