NCARDRS Congenital Anomaly Official Statistics Report, 2021

Figure 7 and Data table 5 show the number of trisomies, categorised by timing of confirmation for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome. As distinct from detection, confirmation is based on a definitive diagnosis from a genetic test and, as such, represents a confirmed diagnosis, for further information see the Technical details. Where timing of confirmation was known, 63.3% (1,115) of babies with Down’s syndrome, 72.9% (399) of Edwards’ syndrome and 65.8% (129) of Patau’s syndrome were confirmed antenatally.

Postnatal diagnoses include babies where the pregnant person has chosen to decline antenatal screening or diagnostic cytogenetic tests but will also include testing performed following a late miscarriage, termination or stillbirth as well as live birth.

Figure 7: Timing of confirmation of condition for babies with Down’s syndrome, Edwards’ syndrome and Patau’s syndrome, in England and the Crown Dependencies, 2021

Figure 8 (Data table 7) shows timing of confirmation by geographical region. There is variation in the timing of confirmation across the regions. There are likely to be several reasons behind this, including some regional variation in ascertainment and data completeness, differences in the population, differences in the age of the pregnant person and uptake of screening. Where a baby has had both a prenatal and a postnatal diagnostic test, the earlier diagnosis is taken as the point of ascertainment.

Figure 8: Timing of confirmation for babies with Down’s syndrome, Edwards’ syndrome and Patau’s syndrome delivered in 2021, by region