# Bridging disciplinary siloes: a scoping review on the inclusion and exclusion of pregnant and lactating populations in clinical research

## TL;DR

This paper reviews how pregnant and lactating people are included or excluded in clinical research and suggests ways to improve ethical and effective inclusion.

## Contribution

A scoping review identifying cross-disciplinary themes and actionable recommendations for including pregnant and lactating populations in clinical research.

## Key findings

- Exclusion of pregnant and lactating people is framed through narratives of vulnerability and risk.
- Recommendations include early preclinical studies and standardized trial endpoints.
- Structural changes and partnerships are needed to address inclusion challenges.

## Abstract

Despite calls for including pregnant and lactating people in clinical research, exclusionary practices persist. Current arguments for inclusion are fragmented and discipline-specific. This scoping review synthesised how inclusion and exclusion of pregnant and lactating populations in clinical research is framed across fields, and identified recommendations for responsible inclusion.

Scoping review.

We searched eight databases from inception to 14 February 2024: MEDLINE, CINAHL, Family & Society Studies Worldwide, SocINDEX, Scopus, Web of Science, Embase and Global Health.

Papers about conceptual or empirical issues related to inclusion or exclusion of pregnant and lactating populations in clinical research. Eligible publications included conceptual analyses, reflections on regulatory and ethical guidance, primary research, review articles, commentaries, viewpoints and editorials.

Two reviewers independently screened and extracted data, developed article summaries and iteratively synthesised findings into themes.

We included 188 papers across bioethics, law and regulation, epidemiology, pharmacology and market and product development. We developed 10 themes: (1) narratives of vulnerability, (2) the injustice of exclusion, (3) risk and overprotection, (4) the unique physiology of pregnancy and lactation, (5) business risks in drug development, (6) informed consent and its limitations, (7) evaluating risks and benefits in maternal-fetal therapies, (8) reliance on animal studies for safety data, (9) designing studies for optimal safety and efficacy and (10) the challenges of detecting adverse events. Recommendations highlight early initiation of preclinical studies, consensus on terminology like ‘minimal risk’, standardised trial endpoints, dedicated funding for research networks, incentives for pharmaceutical companies, capacity strengthening for research ethics committees and partnerships with community-based and patient advocacy organisations.

Challenges to the responsible inclusion of pregnant and lactating populations arise across multiple stages of clinical research. Structural changes through coordinated interventions across the research pipeline are needed to change the status quo.