Guidance

Fetal anomaly screening supporting information

Updated 8 October 2024

Applies to England

Introduction

These revised screening standards for the NHS fetal anomaly screening programme (FASP) replace previous versions. They apply to data collected from 1 April 2022 unless stated otherwise in the document.

The UK National Screening Committee (UK NSC) recommends all eligible pregnant women in England are offered screening to assess the chance of the baby being born with Down’s syndrome (trisomy 21 (T21)), Edwards’ syndrome (trisomy 18 (T18)) and Patau’s syndrome (trisomy 13 (T13)) or a number of physical conditions.

There are 2 pathway requirements specifications (Down’s syndrome, Edwards’ syndrome and Patau’s syndrome screening and 20-week screening scan) available for NHS providers as part of the public health functions exercised by NHS England (NHSE).

National policy is to:

• offer screening to assess the chance of the baby being born with Down’s syndrome, Edwards’ syndrome or Patau’s syndrome - some women may choose not to be screened, or accept screening for some conditions and not others, and it is important their choice is respected
• offer a 20-week screening scan to screen for 11 physical conditions (listed in the overview of the FASP handbook. This ultrasound scan is undertaken between 18 weeks plus 0 days and 20 weeks plus 6 days of pregnancy. The screening pathway must be completed by 23 weeks plus 0 days of pregnancy

More information on the programme, including quality assurance, education and training is available.

See the central glossary of terms, NHS population screening explained and NHS.UK for definition of terms. If you would like to see the meaning of an acronym, hover over it with your cursor and you will be able to see the full definition.

Summary of changes from previous version of standards

We have made changes to the wording of standards where necessary, for example the fetal anomaly ultrasound is now known as the 20-week screening scan.

FASP-S01: coverage: T21, T18, T13 screening

We amended the exclusion category to:

• clarify ‘women who present to the service’ as either dating scan or booking
• move ‘women who choose to have private screening and do not wish to have NHS screening’ to the subset of declines

FASP-S02: coverage: fetal anomaly ultrasound

This standard is now called FASP-S02: coverage: 20-week screening scan.

We amended the exclusion category to:

• move ‘women who choose to have private screening and do not wish to have NHS screening’ to the subset of declines
• move ‘women who are offered an appointment within the optimum time but choose to attend at a different time for personal reasons’ to the subset of women left to follow up

We revised performance thresholds to greater than or equal to 95.0% acceptable level and greater than or equal to 99.0% achievable level.

FASP-S03a test: screen positive rate T21, T18,T13 screening and FASP-S03b test: detection rate T21, T18, T13 screening

We have withdrawn and replaced FASP-S03a and FASP-S03b with a new standard.

This standard is now called FASP-S03: diagnosis or intervention: test turnaround time quantitative fluorescence-polymerase chain reaction (QF-PCR).

This standard was FASP-S09: diagnosis or intervention: diagnostic tests fetal anomaly screening and was renumbered and revised.

FASP-S04: test: fetal anomaly ultrasound

This standard is now called FASP-S04: test: 20-week screening scan.

We:

• added 2 new conditions (coarctation of the aorta and congenital diaphragmatic hernia) to make a 6-part standard

• revised performance thresholds for each condition to:

  • transposition of the great arteries: greater than or equal to 70.0% acceptable, greater than or equal to 99.0% achievable
  • atrioventricular septal defect: greater than or equal to 50.0% acceptable, greater than or equal to 80.0% achievable
  • tetralogy of Fallot: greater than or equal to 55.0% acceptable, greater than or equal to 85.0% achievable
  • hypoplastic left heart syndrome: greater than or equal to 80.0% acceptable, greater than or equal to 99.0% achievable
  • coarctation of aorta: not set
  • congenital diaphragmatic hernia: greater than or equal to 60.0% acceptable, greater than or equal to 70.0% achievable

FASP-S05: test: turnaround time T21, T18,T13 screening

We:

• changed the definition to include sample exclusions
• defined sample receipt as ‘when the sample is received and recorded on the laboratory information management system’
• revised performance thresholds to greater than or equal to 99.0% acceptable level and greater than or equal to 99.5% achievable level

FASP-S06: test: inadequate samples for Down’s syndrome, Edwards’ syndrome and Patau’s syndrome

This standard is now called FASP-S06: test: inadequate samples for T21, T18, T13 screening.

We have introduced acceptable thresholds for this standard. The acceptable threshold for the combined test is less than or equal to 5.0% and less than or equal to 10.0% for the quadruple test. The variation in thresholds reflects performance seen in the first year of data collection. We have not set thresholds for the achievable levels yet; we will keep the data under review and look to set achievable thresholds in the future.

FASP-S07: referral: time to intervention T21, T18, T13 screening

This standard is now called FASP-S07: referral: timeliness to information and support (T21, T18, T13).

We:

• changed the definition from ‘offer’ of appointment to ‘attending’ an appointment. Appointments are defined as either virtual or face to face
• defined the date the maternity service receives the result as day 1

FASP-S08: referral: time to intervention 18 weeks plus 0 days to 20 weeks plus 6 days from fetal anomaly ultrasound

This standard is now called FASP-S08 referral: timeliness to intervention (20-week screening scan).

We:

• we added definitions of local and tertiary referrals
• defined the date of completed screening as day 1
• revised performance thresholds to greater than or equal to 85.0% acceptable level and greater than or equal to 97.0% achievable level
• changed responsibility for submission to National Congenital Anomaly and Rare Disease Registration Service (NCARDRS)

FASP-S09: diagnosis or intervention: diagnostic tests fetal anomaly screening

We:

• renumbered and renamed this standard to FASP-S03: diagnosis or intervention: test turnaround time quantitative fluorescence-polymerase chain reaction (QF-PCR)
• changed this standard from a 4-part standard to a one part standard to measure QF-PCR testing only
• added performance threshold greater than or equal to 95.0% achievable level
• changed responsibility for submission to NCARDRS

Pathway themes

NHS FASP screening standards look at 4 themes to assess the pathway and 3 KPIs are derived from standards 1, 2 and 6.

Theme: coverage

The related standards are:

FASP-S01: coverage: T21, T18, T13 screening

FASP-S02: coverage: 20-week screening scan

Theme: diagnosis or intervention

The related standard is:

FASP-S03: diagnosis or intervention: test turnaround time quantitative fluorescence-polymerase chain reaction (QF-PCR)

Theme: test

The related standards are:

FASP-S04: test: 20-week screening scan

FASP-S05: test: turnaround time T21, T18, T13 screening

FASP-S06: test: inadequate samples for T21, T18, T13 screening

Theme: referral

The related standards are:

FASP-S07: referral: timeliness to information and support (T21, T18 ,T13)

FASP-S08: referral: timeliness to intervention (20-week screening scan)

Resources to support providers and commissioners

Additional FASP operational guidance is included in the programme handbook.

Reporting and publishing standards

We publish annual standards and quarterly KPI data.

Services can also access the quarterly KPI submission templates.