2026-27 Project (Ayers & Webb)

Birth Trauma and Recovery: Analysis of Cortisol Expression (TRACE)

SUPERVISORY TEAM

Supervisor

Professor Susan Ayers at City St George’s
School of Health & Medical Sciences, Department of Nursing and Midwifery
Email: Susan.ayers.1@citystgeorges.ac.uk

Co-Supervisor

Dr Becca Webb at City St George’s
School of Health & Medical Sciences, Department of Nursing and Midwifery
Email: Rebecca.Webb.2@citystgeorges.ac.uk

PROJECT SUMMARY

Project Summary

This project explores how childbirth-related stress is reflected in hair cortisol, a biomarker of chronic stress, in postpartum women. Embedded in the international INTERSECT survey, it examines links between physiological stress, traumatic birth experiences, PTSD, and postpartum depression across multiple countries. The studentship provides training in biomarker analysis, advanced quantitative methods, and interdisciplinary global health research, contributing to a better understanding of birth trauma and postpartum mental health, and informing culturally sensitive interventions.

Project Key Words

birth trauma, post-traumatic stress, cortisol, psychophysiology

MRC LID Themes

Global Health
Health Data Science

Skills

MRC Core Skills

Quantitative skills
Interdisciplinary skills

Skills we expect a student to develop/acquire whilst pursuing this project:

Students will be expected to develop/acquire a wide range of skills whilst working on the TRACE project as follows:

Research Design and Methodology
Understanding and applying observational and cross-national study designs.
Integrating psychological, biological, and contextual data in interdisciplinary research.
Designing and conducting secondary analyses of large-scale international datasets.

Quantitative and Statistical Skills

Advanced statistical analysis, including multilevel modelling and handling clustered data.
Analysis of biomarker data (hair cortisol and other steroid hormones).
Data cleaning, harmonisation, and management for multi-country datasets.

Laboratory and Technical Skills

Understanding biomarker collection procedures, storage, and transport.
Hands-on and observational experience with hair cortisol extraction and LC-MS/MS analysis protocols.
Familiarity with quality control, assay validation, and interpretation of biomarker data.

Psychometric and Psychological Assessment

Working with validated mental health measures, including PTSD and postpartum depression scales.
Linking psychological measures with physiological outcomes.
Critical evaluation of psychometric properties and cultural adaptation of assessment tools.

Interdisciplinary and Global Health Skills

Exposure to cross-cultural research and international collaborations.
Understanding of global maternal mental health disparities and policy contexts.
Communication and coordination with multi-country research teams.

Data Management and Ethics

Secure, anonymised data handling and adherence to data protection regulations.
Ethical considerations in research with vulnerable populations.
Informed consent processes and participant safeguarding in sensitive research areas.

Academic and Professional Skills

Scientific writing for peer-reviewed publications and lay summaries.
Presentation of research findings at conferences or workshops.
Development of skills in grant applications and research dissemination strategies.

Critical Thinking and Problem-Solving

Interpreting complex, multi-dimensional data.
Identifying limitations and potential biases in both psychological and biomarker data.
Formulating research questions and hypotheses in line with international evidence.

Routes

Which route/s are available with this project?

1+4 = No
+4 = Yes

Possible Master’s programme options identified by supervisory team for 1+4 applicants:

Not applicable

Full-time/Part-time Study

Is this project available for full-time study? Yes
Is this project available for part-time study? No

Location & Travel

Students funded through MRC LID are expected to work on site at their primary institution. At a minimum, all students must meet the institutional research degree regulations and expectations about onsite working and under this scheme they may be expected to work onsite (in-person) more frequently. Students may also be required to travel for conferences (up to 3 over the duration of the studentship), and for any required training for research degree study and training. Other travel expectations and opportunities highlighted by the supervisory team are noted below.

Day-to-day work (primary location) for the duration of this research degree project will be at: City St George’s – Clerkenwell campus, London

Travel requirements for this project: For the placement, it is envisaged that the student will spend 3-months working with one of our partners in INTERSECT Africa, a network of researchers in sub-Saharan African countries who are conducting or have conducted INTERSECT. For training in biomarker analysis the student will spend 2 months at the Institute of Biological Psychology, Faculty of Psychology, Technische Universität Dresden, Dresden, Germany, to work with Professor Kirschbaum to be trained in, and conduct, the biomarker analysis.

Eligibility/Requirements

Particular prior educational requirements for a student undertaking this project

Minimum standard institutional eligibility criteria for doctoral study at City St George’s
Masters degree in a health-related discipline.

Other useful information

Potential Industrial CASE (iCASE) conversion? = No

PROJECT IN MORE DETAIL

Scientific description of this research project

Childbirth-related stress and postpartum posttraumatic stress disorder (CB-PTSD), represent a substantial global health burden. Approximately 1 in 5 women experience childbirth as traumatic, and 1 in 25 develop CB-PTSD. While self-report measures provide valuable insights, they are subject to recall bias, stigma, and cultural influences. To develop more comprehensive biopsychosocial understanding of CB-PTSD and postpartum mental health, it is critical to complement subjective reports with objective biological markers of chronic stress. Hair cortisol concentration (HCC) offers a validated, retrospective measure of hypothalamic-pituitary-adrenal (HPA) axis activity, reflecting stress over previous months. Unlike salivary or blood cortisol, HCC is unaffected by daily fluctuations. Evidence suggests HCC correlates with perinatal depression, anxiety, and trauma history, but associations with traumatic birth, CB-PTSD, and postpartum depression remain underexplored, particularly in cross-cultural contexts. The TRACE study will be embedded in the INTERSECT international survey, which has collected standardised data on childbirth-related trauma and maternal mental health across 31+ countries. Embedding a biomarker study within this framework enables examination of physiological correlates of birth trauma in diverse populations. Integrating HCC with validated psychological measures, sociodemographic data, and contextual information on healthcare and socioeconomic inequality allows testing of diathesis-stress models and exploration of cross-national differences in stress responses. The findings will inform biopsychosocial models of postpartum CB-PTSD and mental health and support the development of culturally sensitive interventions and policies.

Design and Setting: TRACE is an observational sub-study nested within INTERSECT. TRACE is being conducted in up to 15 countries, including high-, middle-, and low-income settings. This PhD will conduct TRACE in the UK, and work with other countries conducting TRACE to link and analyse the data. Recruitment occurs via the INTERSECT survey of women 6-12 weeks postpartum.

Participants: Eligibility for TRACE includes sufficient scalp hair (≥2 cm), no recent use of glucocorticoid-containing medication, and no serious illness affecting cortisol metabolism. Sample size will vary by country depending on survey progress.

Hair Sample Collection and Analysis: Participants or trained staff collect a 2-4 cm strand (~3 mm diameter) from the scalp, reflecting cortisol secretion over the previous 2-4 months. Samples are anonymised and sent to the laboratory at Technische Universität Dresden for LC-MS/MS analysis of cortisol and related steroid hormones. The PhD student will visit the laboratory to train in and analyse the UK biomarker data. Anonymised numerical results are returned to country teams for linkage with INTERSECT survey data for that country.

Data Integration and Management: Local datasets are securely merged into the international INTERSECT-TRACE database maintained by the UK core team. Data harmonisation ensures cross-country comparability. The final dataset will be deposited with the UK Data Service.

Analysis: Multilevel models will examine associations between HCC and psychological outcomes, accounting for country-level clustering. Cross-country comparisons and secondary analyses will explore the influence of contextual factors such as healthcare quality and socioeconomic status.

Ethical Considerations: Ethical approval will be obtained in all participating countries. Informed consent is required for hair collection and anonymised data sharing. By integrating biological, psychological, and contextual data across international populations, INTERSECT and TRACE address a global health concern and advance understanding of physiological processes in childbirth-related stress and trauma, supporting the development of evidence-informed interventions worldwide.

Additional information from the supervisory team

The supervisory team has provided a recording for prospective applicants who are interested in their project. This recording should be watched before any discussions begin with the supervisory team.

Ayers & Webb Recording

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