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  6. 1st Trimester Screening for Trisomy 21 (T21), Trisomy 18 (T18), Trisomy 13 (T13) in Singleton pregnancies: Nuchal Translucency (NT) Scan (499)
Important: please update your RDS app to version 4.7.3

Welcome to the March 2025 update from the RDS team

1.     RDS issues - resolutions

1.1 Stability issues - Tactuum implemented a fix on 24th March which we believe has finally addressed the stability issues experienced over recent weeks.  The issue seems to have been related to the new “Tool export” function making repeated calls for content when new toolkit nodes were opened in Umbraco. No outages have been reported since then, and no performance issues in the logs, so fingers crossed this is now resolved.

1.2 Toolkit URL redirects failing– these were restored manually for the antimicrobial calculators on the 13th March when the issue occurred, and by 15th March for the remainder. The root cause was traced to adding a new hostname for an app migrated from another health board and made live that day. This led to the content management system automatically creating internal duplicate redirects, reaching the maximum number of permitted redirects and most redirects therefore ceasing to function.

This issue should not happen again because:

  • All old apps are now fully migrated to RDS. The large number of migrations has contributed to the high number of automated redirects.
  • If there is any need to change hostnames in future, Tactuum will immediately check for duplicates.

1.3 Gentamicin calculators – Incidents have been reported incidents of people accessing the wrong gentamicin calculator for their health board.  This occurs when clinicians are searching for the gentamicin calculator via an online search engine - e.g. Google - rather than via the health board directed policy route. When accessed via an external search engine, the calculator results are not listed by health board, and the start page for the calculator does not make it clearly visible which health board calculator has been selected.

The Scottish Antimicrobial Prescribing Group has asked health boards to provide targeted communication and education to ensure that clinicians know how to access their health board antimicrobial calculators via the RDS, local Intranet or other local policy route. In terms of RDS amendments, it is not currently possible to change the internet search output, so the following changes are now in progress:

  • The health board name will now be displayed within the calculator and it will be made clear which boards are using the ‘Hartford’ (7mg/kg) higher dose calculator
  • Warning text will be added to the calculator to advise that more than one calculator is in use in NHS Scotland and that clinicians should ensure they access the correct one for their health board. A link to the Right Decision Service list of health board antimicrobial prescribing toolkits will be included with the warning text. Users can then access the correct calculator for their Board via the appropriate toolkit.

We would encourage all editors and users to use the Help and Support standard operating procedure and the Editors’ Teams channel to highlight issues, even if you think they may be temporary or already noted. This helps the RDS team to get a full picture of concerns and issues across the service.

 

2.     New RDS presentation – RDS supporting the patient journey

A new presentation illustrating how RDS supports all partners in the patient journey – multiple disciplines across secondary, primary, community and social care settings – as well as patients and carers through self-management and shared decision-making tools – is now available. You will find it in the Promotion and presentation resources for editors section of the Learning and support toolkit.

3.     User guides

A new user guide is now available in the Guidance and tips section of Resources for providers within the Learning and Support area, explaining how to embed content from Google Calendar, Google Maps, Daily Motion, Twitter feeds, Microsoft Stream and Jotforms into RDS pages. A webinar for editors on using this new functionality is scheduled for 1 May 3-4 pm (booking information below.)

A new checklist to support editors in making all the checks required before making a new toolkit live is now available at the foot of the “Request a new toolkit” standard operating procedure. Completing this checklist is not a mandatory part of the governance process, but we would encourage you to use it to make sure all the critical issues are covered at point of launch – including organisational tags, use of Alias URLs and editorial information.

4.Training sessions for RDS editors

Introductory webinars for RDS editors will take place on:

  • Tuesday 29th April 4-5 pm
  • Thursday 1st May 4-5 pm

Special webinar for RDS editors – 1 May 3-4 pm

This webinar will cover:

  1. a) Use of the new left hand navigation option for RDS toolkits.
  2. b) Integration into RDS pages of content from external sources, including Google Calendar, Google Maps and simple Jotforms calculators.

Running usage statistics reports using Google analytics

  • Wednesday 23rd April 2pm-3pm
  • Thursday 22nd May 2pm-3pm

To book a place on any of these webinars, please contact Olivia.graham@nhs.scot providing your name, role, organisation, title and date of the webinar you wish to attend.

5.New RDS toolkits

The following toolkits were launched during March 2025:

SIGN guideline - Prevention and remission of type 2 diabetes

Valproate – easy read version for people with learning disabilities (Scottish Government Medicines Division)

Obstetrics and gynaecology induction toolkit (NHS Lothian) – password-protected, in pilot stage.

Oral care for care home and care at home services (Public Health Scotland)

Postural care in care homes (NHS Lothian)

Quit Your Way Pregnancy Service (NHS GGC)

 

6.New RDS developments

Release of the redesign of RDS search and browse, archiving and version control functionality, and editing capability for shared content, is now provisionally scheduled for early June.

The Scottish Government Realistic Medicine Policy team is leading development of a national approach to implementation of Patient-Reported Outcome Measures (PROMs) as a key objective within the Value Based Health and Care Action Plan. The Right Decision Service has been commissioned to deliver an initial version of a platform for issuing PROMs questionnaires to patients, making the PROMs reports available from patient record systems, and providing an analytics dashboard to compare outcomes across services.  This work is now underway and we will keep you updated on progress.

The RDS team has supported Scottish Government Effective Prescribing and Therapeutics Division, in partnership with Northern Ireland and Republic of Ireland, in a successful bid for EU funding to test develop, implement and assess new integrated care pathways for polypharmacy, including pharmacogenomics. As part of this project, the RDS will be working with NHS Tayside to test extending the current polypharmacy RDS decision support in the Vision primary care electronic health record system to include pharmacogenomics decision support.

7. Implementation projects

We have just completed a series of three workshops consulting on proposed improvements to the Being a partner in my care: Realistic Medicine together app, following piloting on 10 sites in late 2024. This app has been commissioned by Scottish Government Realistic Medicine to support patients and citizens to become active partners in shared decision-making and encouraging personalised care based on outcomes that matter to the person. We are keen to gather more feedback on this app. Please forward any feedback to ann.wales3@nhs.scot

 

 

1st Trimester Screening for Trisomy 21 (T21), Trisomy 18 (T18), Trisomy 13 (T13) in Singleton pregnancies: Nuchal Translucency (NT) Scan (499)

Please report any inaccuracies or issues with this guideline using our online form

Appointments for a dating scan including 1st trimester screening for Down’s, Edwards’ and Patau’s Syndrome (NT measurements) should be no less than 25 minutes. This should include time to get “on and off the couch”, time to perform the ultrasound examination and time to complete the report.

All Sonographers performing NT measurements must be appropriately trained and accredited and their results subjected to rigorous audit and performance management. To assure continuing satisfactory performance each Sonographer must perform a minimum of 25 nuchal translucency measurements every 6 months and have DQASS ‘Green’ or ‘Amber’ flag status.

The ultrasound equipment used must meet NSC FASP specifications. It should have a cineloop function and calliper precision to one decimal point i.e. 0.1mm. Operators should be aware of and adhere to BMUS guidelines for safe use of ultrasound including exposure times.

The screening period is between 11+2 to 14+1 weeks gestation. The scan will be targeted at a gestation of approx 12 weeks. The scan can be performed by the transabdominal or transvaginal route.

Sonographers must ensure formal consent has been obtained. Check the details of the booking on the ‘antenatal assessment’ tab on Badger net under ‘screening and scans offered/accepted or declined'.

Women can chose to have screening for T21 syndrome only or to have screening for T21, T18 & T13. It is not possible to have screening for T18 and/or T13 without screening for T21.

Prior to beginning scan, give a brief explanation of the scan, including limitations and obtain verbal consent to continue.

If consent for 1st trimester screening is not obtained a “dating” scan only should be performed. The Sonographer should also advise that if an increased NT ≥ 3.5mm is detected, this can be indicative of a structural abnormality and would require referral to a Medical Sonographer.

Where both dating and 1st trimester screening are requested and the CRL is between 45.0 and 84.0mm, the pregnancy should be dated using the CRL measurement.

Criteria for measurement of the fetal crown rump length (CRL) as part of the combined 1st trimester screening programme

The CRL range should be between 45.0 and 84.0 mm.

The magnification of the fetus should be as large as possible clearly demonstrating the entire crown-rump length.

A midline sagittal section of the whole fetus should be obtained with the fetus horizontal on the screen, either supine or prone. The fetus should be in a neutral position with fluid visible between the fetal chin and chest, neither hyper extended nor flexed.

The best of three measurements should be taken. Linear callipers should be used to measure the maximum un-flexed length. Intersection of the callipers (+) should be placed on the outer margin of the skin borders of the CRL. Two images of the measured CRL must be retained, one for the patient record and one for audit purposes.

If the CRL is < 45.0mm re-appoint the patient within the 11+2 – 14+1 weeks screening window.

If the CRL is > 84.0mm arrange appointment for 2nd trimester biochemistry screening and date pregnancy using Head Circumference (HC).

The NT Measurement

The NT measurement should only be performed if a CRL measurement, which meets the recommended NHS FASP criteria for CRL has been obtained.

Criteria for measurement of the fetal nuchal translucency (NT) measurement

A midline sagittal section of the fetus should be obtained. The fetus should be horizontal on the screen, either supine or prone.

Care must be taken to distinguish between fetal skin and amnion. The fetus should be in a neutral position.

The image should be magnified, such that only the fetal head and upper thorax occupy the whole screen. In magnifying the image (pre- or post-zoom) it is important to turn down the gain.

The widest part of the translucency must always be measured. Measurements should be taken with the horizontal lines of the callipers placed ON the lines that define the NT thickness.

During the scan more than one measurement must be taken and the maximum one which meets all the criteria should be recorded. Two images of this measured NT should be retained, one for the patient record, one for audit purposes.

If the NT measurement is ≥ 3.5mm, perform combined screening test and follow pathway for raised nuchal translucency (NT) ≥ 3.5mm

Too early/late/unable to obtain measurements

Too Early: CRL measurement <45.0mm – re-appoint at appropriate gestation.

Too late: CRL measurement >84.0mm – arrange appointment for 2nd trimester biochemistry (≥ 15+0 weeks) screening and date pregnancy using Head Circumference (HC).

Unable to obtain measurements – offer a 2nd attempt. This second attempt at screening should be on the same day.

If unable to obtain measurements after two attempts, explain limitations of scan and record on report. Arrange 2nd trimester dating scan to coincide with biochemistry appointment.

Ultrasound Images

One set of paired CRL and NT images to be inserted into brown image envelope in patient notes, one set to be kept aside for audit purposes.

Ultrasound Report

The Ultrasound report should be documented on Badgernet under ‘Key Notes – New Ultrasound Note’. Ensure all appropriate fields are filled including the authorization box (your digital signature) for the report to be valid.

If unable to obtain NT measurements indicate reason for failed attempt i.e. poor views due to fetal position. If patient to be re-appointed for 2nd trimester screening enter suggested date.  

Medical Genetics Form (Appendix A)

Attach a patient label, with name, address, DOB and CHI number to the Medical Genetics First Trimester Combined Ultrasound and Biochemical (CUB) Screening form.

Enter the following data:

  • Hospital
  • Consultant
  • Maternal Weight
  • Number of Fetuses
  • Chorionicity if multiple pregnancy
  • Maternal Family Origin

Indicate YES or NO for the following categories:

  • Screening required – Down’s Syndrome T21
  • Screening required – Edwards’ Syndrome T18 and Patau’s Syndrome T13
  • Current Smoker
  • Previous Trisomy Pregnancy
  • IDDM

Complete the Ultrasound Details section;

  • Date of scan
  • Estimated date of delivery
  • CRL (mm)
  • NT (mm)
  • Ultrasonographer code

If assisted conception pregnancy, record all relevant details in the Assisted Conception section

“Date of sample” and “Sample taken by” fields to be entered by the Midwife/HCSW who performs the venipuncture.

Medical Genetics form to be passed to the Midwife/HCSW for completion and sent together with the biochemistry sample to Medical Genetics Labs.

Medical Genetics, First Trimester Combined Ultrasound and Biochemical (CUB) Screening Form.

 

Editorial Information

Last reviewed: 03/05/2024

Next review date: 04/05/2028

Author(s): Donna Bean.

Version: 3

Co-Author(s): Alan Mathers.

Approved By: Maternity Governance Group

Document Id: 499