NCARDRS Congenital Condition Official Statistics Report, 2023

Trisomy is a condition that results in an extra copy of a chromosome in all or some of an individual’s cells. Down’s syndrome (Trisomy 21), Edwards’ syndrome (Trisomy 18) and Patau’s syndrome (Trisomy 13) are the most common forms of trisomy associated with pregnancies that can progress to full term. To ensure consistency throughout the report and internationally, partial trisomies are also included in the trisomy groups for prevalence reporting. 

Figure 1c (Data table 1a) shows the birth prevalence per 10,000 total births in 2023 was 30.1 (95% CI 28.7-31.6) - or one in every 332  total births - for Down’s syndrome,  8.3 (95% CI 7.6-9.1)  - or one in every 1,203 total births – for Edwards’ syndrome,  and 3.5 (95% CI 3.0-4.0)  - or one in every 2,856 total births for Patau’s syndrome. 

Live birth prevalence per 10,000 live births in 2023 was 11.5 (95% CI 10.7-12.4) - or one in 868 live births - for Down’s syndrome, 1.0 (95% CI 0.8-1.3) - or one in 9711 - for Edwards’ syndrome and 0.5 (95% CI 0.4-0.8) - or one in 18,774 - for Patau’s syndrome respectively. 

Total and live birth prevalence for all three conditions in 2023 were consistent with estimates published for 2022.