Data
Updated 8 October 2024
Applies to England
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This publication is available at https://www.gov.uk/government/publications/fetal-anomaly-screening-programme-handbook/data
For naming conventions used throughout this guidance and other general information, please see the handbook overview.
An annual data report sets out data collected from the NHS Fetal Anomaly Screening Programme (FASP).
A joint antenatal screening standards data report is also available.
1. Screening standards
Screening standards provide a way of measuring how well screening programmes are performing in important areas.
Key performance indicators (KPIs) are a subset of the screening standards for the NHS screening programmes.
2. Data submissions
The NHS FASP will monitor the detection rates (DR) and screen positive rates (SPR) of the combined and quadruple tests against performance thresholds set for the national programme.
In Down’s syndrome, Edwards’ syndrome and Patau’s syndrome screening the DR and SPR increase with maternal age.
2.1 Test performance for T21, T18 and T13
Down’s syndrome quality assurance support service (DQASS) and National Congenital Anomaly and Rare Disease Registration Service (NCARDRS) monitor the SPR and DR for T21, T18 and T13.
The table below outlines SPR for the conditions screened for in both singleton and twin pregnancies.
| Screening strategy | Expected standardised SPR (%) | Acceptable standardised SPR (%) | Achievable standardised SPR (%) |
|---|---|---|---|
| Combined (T21, T18 and T13) | 2.6 | 2.2 to 3.0 | 2.3 to 2.9 |
| Combined (joint T18 and T13) | <0.2 | 0.1 to 0.2 | 0.13 to 0.17 |
| Combined (T21) | 2.6 | 2.2 to 3.0 | 2.3 to 2.9 |
| Quadruple (T21 only) | 4.0 | 3.6 to 4.4 | 3.7 to 4.3 |
The table below outlines DR for the conditions screened for in both singleton and twin pregnancies.
DR are standardised according to the maternal age distribution in England.
| Condition (screening test) | Standardised DR for singleton (%) | Standardised DR for monochorionic twins (%) | Standardised DR for dichorionic twins (%) |
|---|---|---|---|
| T21 (combined) | 86 | 86 | >80 |
| T18, T13 (combined) | 80 | 80 | 80 |
| T21 (quadruple) | 82 | 82 | 50 |
2.2 Test performance for the 11 physical conditions
NCARDRS monitors the DR for the 11 physical conditions.
Screening laboratories must provide a monthly report of all higher chance results from the combined test and quadruple test. This report must use the data set requirements provided by the NCARDRS team for antenatal screening.
Providers also have a role in reporting to NCARDRS using the data collection forms for antenatal, delivery and postnatal data.
Thresholds for performance for the 11 physical conditions screened for at the 20-week screening scan are shown in the table below.
It is important to note that some conditions may be detected earlier in pregnancy, and the thresholds in the table reflect the overall DR across all the NHS FASP screening pathways.
| Physical conditions | Detection rate thresholds (%) |
|---|---|
| Anencephaly | 98 |
| Spina bifida | 90 |
| Cleft lip | 75 |
| Congenital diaphragmatic hernia | 60 |
| Gastroschisis | 98 |
| Exomphalos | 80 |
| Serious cardiac conditions including transposition of the great arteries, atrioventricular septal defect, tetralogy of fallot and hypoplastic left heart syndrome | 50 |
| Bilateral renal agenesis | 84 |
| Severe skeletal dysplasia | 60 |
| Edwards’ syndrome | 95 |
| Patau’s syndrome | 95 |