Congenital Conditions in Scotland: Screening, Pregnancy Outcomes and Child Health Research

Roy Weir Fellowship project (October 2025 – April 2028)

Changes to prenatal screening for Down’s syndrome in Scotland: test pathway choices, experiences of non-invasive prenatal testing (NIPT), and first-line NIPT feasibility

Building on findings from the MRS-funded doctoral project, this project aims to:

1. Explore the impact of the change in pregnancy screening choices before and after NIPT implementation in Scotland for women whose baby was subsequently diagnosed with Down’s syndrome before or after birth (or pregnancy loss).
2. Explore the experiences of women and healthcare professionals of NIPT implemented in the NHS in Scotland, and investigate views on the barriers and facilitators for replacing current first-line antenatal screening for chromosomal conditions (Down’s syndrome, Edwards’ syndrome and Patau’s syndrome) with non-invasive prenatal testing (NIPT).
3. Investigate the cost-effectiveness of first-line NIPT implementation in Scotland.

This research is a 2.5 year funded postdoctoral fellowship project, funded by the University of Aberdeen Roy Weir Fellowship. Find more information about the planned research here.

Medical Research Scotland PhD project (October 2021 – September 2025)

Introduction of Non-Invasive Prenatal Testing (NIPT) in Scotland: historical trends and impact on pregnancy decisions and outcomes of babies with Down’s syndrome  

This doctoral project (2021-2025) was funded by the Medical Research Scotland PhD Studentships Programme, in collaboration with Public Health Scotland (PHS), and aimed to investigate the impact of implementing non-invasive prenatal testing (NIPT) into the Scottish antenatal screening programme for Down's syndrome.

Dr Rute Vieira at the Institute of Applied Health Sciences at the University of Aberdeen (UoA) was the principal supervisor, supported by a team of academics and data analysts from the University of Aberdeen and Public Health Scotland (PHS).

The study analysed data from the Scottish congenital condition registers, population-wide clinical data, and prenatal screening and genetic datasets to evaluate the real-world impact of introducing NIPT into the screening programme for Down's syndrome in Scotland.

The research provided an overview of NIPT implementation worldwide, and historical trends for the Scottish population of babies with DS between 2000-2021. The findings give qualitative and quantitative insights into how NIPT may have impacted decisions on screening, diagnosis, and pregnancy continuation.

Findings from this project highlight the importance of integrating qualitative and quantitative methodologies, to ensure antenatal screening meets users’ needs and supports informed decision-making during pregnancy.  

The outputs from this study can be found in the resources and publications sections.

“This project builds on previous work by the Congenital Conditions and Rare Diseases Registration Information Service for Scotland (CARDRISS) team in Public Health Scotland, specifically the creation of the Scottish linked congenital conditions dataset (SLiCCD). This important resource captures data on all pregnancies and births diagnosed with a congenital condition in Scotland since 2000. Really, this is what makes the analysis in our project possible - the ability to look at a population level at the impact of changes to the Scottish screening programme for specific congenital conditions."
- Dr Rute Vieira, Principal Supervisor of the Doctoral project

Medical Research Scotland Funded PhD Project (2021-2025)

The approach of this research was to:

1. Review the literature

To understand where NIPT has been offered by national health systems around the world, and how this has been achieved.

A systematic review and meta-analysis explored the extent of NIPT implementation globally, its uptake, and impact on invasive prenatal diagnostic testing, live births and terminations of pregnancy in these populations.

See ‘Publications’ to view the systematic review and meta-analysis.

2. Understand our data

To check how well the different datasets from Public Health Scotland (PHS) correctly identified babies with Down's syndrome (DS) in Scotland.

To undertake descriptive analysis of our study cohort within the Scottish Linked Congenital Conditions Dataset (SLiCCD) provided by PHS, which described singleton pregnancies where the baby was diagnosed with DS in Scotland from January 2000 to December 2021. Case ascertainment explored how well SLiCCD captured babies with DS in the population.

3. Explore changes before and after NIPT

To understand the time trends in total and live birth prevalence of Down’s syndrome in Scotland from 2000-2021 and associated maternal socio-demographic factors. To also explore the screening and diagnostic history of women booking for antenatal care whose baby was diagnosed with DS during or after pregnancy (or pregnancy loss), directly before and after NIPT implementation (2019 – 2022), and understand differences between socio-demographic groups.

4. Investigate experiences of NIPT

To explore the experiences of accessing NIPT for Down’s syndrome screening through the NHS using qualitative thematic analysis of public online discussion threads.

Thematic analysis of online Mumsnet discussion forums provided insight into the experiences and views of women offered NIPT through the NHS.

MRS PhD Project Team

• PhD Student – Elinor Sebire, Institute of Applied Health Sciences, University of Aberdeen
• Principal Supervisor – Dr Rute Vieira, Senior Lecturer in Medical Statistics at the University of Aberdeen and consultant for Public Health Scotland 
• Secondary Supervisor – Professor Amudha Poobalan, Professor of Public Health Education, based at the School of Medicine, Medical Sciences and Nutrition at the University of Aberdeen
• External Supervisor – Dr Rachael Wood, Consultant in Public Health Medicine at Public Health Scotland

In memoriam

Very sadly, Dr Sohinee Bhattacharya passed away in the summer of 2023. She was a treasured member of our team and, as secondary supervisor, was pivotal in the conception and progress of the project for the last two years. Sohinee brought her much respected clinical and academic expertise to this project, and her contributions and valuable insights to this work will be long remembered.

Down's syndrome is a condition where an individual has three full or partial copies of chromosome 21, otherwise known as trisomy 21. There are approximately 47,000 individuals living with Down's syndrome in the UK according to the Down's Syndrome Association (DSA).

Every child with Down's syndrome is unique, following the same developmental path as all children. Most individuals with Down's syndrome will have some form of learning impairment, and some will have more complex needs, although everyone is different.

Many people with Down's syndrome lead happy and fulfilled lives, living as independently as possible and pursuing activities and occupations into their 60s, 70s and beyond. More information and insight into the lives of people with Down's syndrome can be found through the following websites:

• Down's Syndrome Association (DSA)
• NHS Inform
• Down's Syndrome Scotland

Non-invasive prenatal testing was introduced to the Scottish antenatal screening programme in September 2020.

Before September 2020

Routine screening was available for Down's syndrome only and was offered to all women with a singleton pregnancy. Women that opted for screening tests were given a chance score for the baby having Down's syndrome. This score was based on a combination of maternal blood samples and ultrasound measurements, depending on the gestation of pregnancy. Down's syndrome screening for twin pregnancies was only offered in the first trimester.

If a pregnancy was given a higher chance of Down's syndrome (i.e. >= 1 in 150), the mother was offered an invasive test to confirm the condition. These diagnostic tests (amniocentesis or chorionic villus sampling) have, however, a small risk of miscarriage.

At each stage, women could decide not to have any further testing.

This screening pathway for Down's syndrome is represented in Figure 1.

Figure 1: Flow diagram to represent the screening options for Down's syndrome for a singleton pregnancy before September 2020.

Since September 2020

All pregnant women booking for antenatal care are now offered screening for Down's, Edwards' and Patau's syndromes if they are in their first three months of pregnancy. Women that opt for screening tests, are given a chance score for the baby having either Down's syndrome or, separately, either Edwards' or Patau's syndrome, based on the same testing as before (now referred to as first line screening). Screening has also been extended to twin pregnancies in the first and second trimester for Down's syndrome.

If the chance of the baby having a specific condition is higher, women are offered another screening test called non-invasive prenatal test (NIPT), for which women only need to give a blood sample and will be told whether there is a high or low chance that the baby has the condition.

NIPT is a more accurate screening test for these three conditions, and it will hopefully reduce the need for pregnant women to undergo invasive tests. However, women can still choose to do an invasive test instead, or no further screening tests (Figure 2).

If the NIPT result is positive, women are then offered invasive testing, or no further testing.

Figure 2: Screening options available for singleton pregnancies for Down's syndrome following the September 2020 implementation of NIPT. First line screening test refers to the combined or quadruple screening available before NIPT was introduced.

Non-invasive prenatal testing (NIPT) is a screening test that analyses genetic material released from the placenta, called cell-free DNA (cfDNA). cfDNA circulates in the maternal blood stream during pregnancy and can be used for NIPT from 11 weeks gestation.

When used as a screening test, NIPT has been found to have over 99% accuracy for Down's syndrome (Taylor-Philips et al., 2016), meaning it is much more accurate than the first line screening tests. However, this is still a screening test, and there is a very small chance of being incorrect. Therefore, NIPT is not enough to diagnose a baby with Down's syndrome. To get a definitive answer for whether a baby has Down's syndrome before birth, invasive testing such as amniocentesis or chorionic villus sampling, must still be used.

For further information on NIPT please visit the NHS inform website .

MRS PhD project resources

• Study protocol: Long term trends in prevalence of Down’s syndrome in Scotland (2000-2021)
• Chief Medical Officer letter of NIPT implementation for Scotland in 2020
• Systematic review protocol: PROSPERO protocol

Roy Weir Fellowship Resources

Further Information and Resources

• NHS inform website
• Public Health Scotland website
• Down's Syndrome Scotland website
• Medical Research Scotland website
• Antenatal Results and Choices website

MRS PhD

The implementation and impact of non-invasive prenatal testing (NIPT) for Down's syndrome into antenatal screening programmes: A systematic review and meta-analysis

Sebire E, Rodrigo CH, Bhattacharya S, Black M, Wood R, Vieira R (2024) The implementation and impact of non-invasive prenatal testing (NIPT) for Down's syndrome into antenatal screening programmes: A systematic review and meta-analysis. PLoS ONE 19(5): e0298643. https://doi.org/10.1371/journal.pone.0298643

Press release

Roy Weir Fellowship

Other Publications

Pregnancy Screening for Down's Syndrome, Edwards' Syndrome, and Patau's Syndrome in Scotland

Public Health Scotland Official Statistics in Development: Pregnancy Screening for Down's Syndrome, Edwards' Syndrome, and Patau's Syndrome in Scotland. https://publichealthscotland.scot/publications/pregnancy-screening-for-down-s-syndrome-edwards-syndrome-and-patau-s-syndrome-in-scotland/pregnancy-screening-for-down-s-syndrome-edwards-syndrome-and-patau-s-syndrome-in-scotland/

Trends in neural tube defects in Scotland 2000-2021 prior to the introduction of mandatory folic acid fortification of non-wholemeal wheat flour: a population-based study

Kirolos, A., Vieira, R., Calvert, C., Griffiths, E., & Wood, R. (2025). Trends in neural tube defects in Scotland in 2000-2021 prior to the introduction of mandatory folic acid fortification of non-wholemeal wheat flour: a population-based study. Archives of disease in childhood, 110(11), 878–884. https://doi.org/10.1136/archdischild-2024-328295