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

This research programme investigates how changes to prenatal screening for Down’s syndrome influence screening decisions, pregnancy outcomes, and service planning in Scotland.

The work builds on findings from a Medical Research Scotland-funded PhD project conducted in collaboration with Public Health Scotland, which analysed national population data to understand long-term trends in Down’s syndrome diagnoses and births in Scotland between 2000 and 2021.

The programme also includes research supported by the Roy Weir Fellowship from Down’s Syndrome Scotland, which examines the impact of introducing non-invasive prenatal testing (NIPT) into the Scottish antenatal screening programme. This work explores how the introduction of NIPT has influenced screening pathways and decision-making for expectant parents, including the choices women make about screening and diagnostic testing.

As part of the fellowship, the research will also investigate the experiences of women and healthcare professionals involved in the screening pathway and assess the potential health and economic implications of introducing NIPT as a first-line screening test in Scotland, including an evaluation of its cost-effectiveness for the NHS.

Together, this programme of research aims to provide evidence to support informed decision-making for pregnant women and to inform the future development of antenatal screening policy and services in Scotland.

Medical Research Scotland Funded PhD Project (2021-2025)

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 Studentship Programme and conducted in collaboration with Public Health Scotland (PHS). The project aimed to investigate the impact of introducing non-invasive prenatal testing (NIPT) into the Scottish antenatal screening programme for Down’s syndrome.

The research used national population datasets, congenital condition registers, prenatal screening data, and genetic testing records to evaluate the real-world impact of NIPT implementation in Scotland. The project combined quantitative and qualitative methods to understand how changes to the screening pathway may influence screening uptake, diagnostic testing, pregnancy decisions, and outcomes for babies with Down’s syndrome.

Key outputs from this research programme include:

National trends in Down’s syndrome prevalence in Scotland (2000–2021) using the Scottish Linked Congenital Conditions Dataset (SLiCCD) [link to paper in Publications tab]

• A systematic review and meta-analysis examining the implementation and impact of non-invasive prenatal testing (NIPT) in antenatal screening programmes worldwide, which identified NIPT implementation in at least 27 countries and demonstrated reductions in invasive prenatal diagnostic testing following its introduction. 

 Forthcoming publications

• Exploring women’s experiences of NIPT within the NHS screening pathway
• Examining changes in screening and diagnostic testing decisions following the introduction of NIPT in Scotland
• Pregnancy and early childhood outcomes for babies with Down’s syndrome in Scotland (2000–2021) using national population data.

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

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 .

• Chief Medical Officer letter of NIPT implementation for Scotland in 2020
• NHS inform website
• Public Health Scotland website
• Down's Syndrome Scotland website
• Medical Research Scotland website
• Antenatal Results and Choices website

Total and live birth prevalence of singleton pregnancies with Down’s Syndrome in Scotland between 2000 and 2021: a population based study

Sebire, E., Wood, R., Calvert, C., Vieira, R. (2026) Total and live birth prevalence of singleton pregnancies with Down’s Syndrome in Scotland between 2000 and 2021: a population-based study. The Lancet Regional Health – Europe. Accepted/In press

Pregnancy, baby, and childhood outcomes from using anti-seizure medication during pregnancy

Moore, E., Millar, M., Merrick, R., Mueller, T., Stark, V., Jarvis, L., Kurdi, A., Hopkins, L., McTaggart, S., Vieira, R., Bennie, M., Wood, R. (2026) Pregnancy, baby, and childhood outcomes from using anti-seizure medication during pregnancy. Communications Medicine, vol. 6, 28. https://doi.org/10.1038/s43856-025-01285-9 

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

Study protocol: Long term trends in prevalence of Down’s syndrome in Scotland (2000-2021)

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

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/

Systematic review protocol: PROSPERO protocol