Excluding pregnant women from clinical drug trials raises ethical and safety concerns, as it limits evidence-based treatment options during pregnancy and may expose fetuses to unknown risks, according to a recent discussion in Deutsches Ärzteblatt. This practice, whereas intended to protect maternal and fetal health, ultimately hinders the development of safe, effective therapies for pregnant patients who require medication for chronic or acute conditions.
Why the Exclusion of Pregnant Women in Trials Persists Despite Ethical Guidelines
Historically, pregnant individuals have been excluded from early-phase clinical trials due to precautionary principles stemming from past tragedies like thalidomide. Although, this exclusion continues even in later phases where safety profiles are better understood. Current guidelines from the International Council for Harmonisation (ICH) and the U.S. Food and Drug Administration (FDA) encourage inclusion when risks are minimal and justified, yet implementation remains inconsistent. A 2024 analysis in JAMA Network Open found that only 22% of industry-sponsored Phase III trials between 2018 and 2023 included pregnant participants, despite 65% of women of reproductive age using at least one prescription medication during pregnancy.
In Plain English: The Clinical Takeaway
- Pregnant people are routinely left out of drug studies, which means doctors often lack solid evidence to prescribe medications safely during pregnancy.
- This gap forces clinicians to rely on animal data or case reports, increasing uncertainty about fetal risks and maternal efficacy.
- Including pregnant women in research—with proper safeguards—can improve health outcomes without compromising safety, as demonstrated in recent HIV and antiviral trials.
Geopolitical and Regulatory Implications: FDA, EMA, and NHS Perspectives
The ethical dilemma varies across regulatory jurisdictions. In the United States, the FDA’s 2021 guidance emphasizes that pregnant women should be presumed eligible for clinical research unless there is a specific, scientifically justified reason for exclusion. Similarly, the European Medicines Agency (EMA) updated its guideline in 2022 to promote proactive inclusion strategies, particularly for vaccines and antivirals. In contrast, the UK’s National Health Service (NHS) relies heavily on data from the UK Teratology Information Service (UKTIS), which collects real-world outcomes but lacks the rigor of controlled trials. Pregnant patients in the UK often receive off-label prescriptions based on limited pharmacovigilance data, a practice highlighted in a 2023 The Lancet Infectious Diseases study showing inconsistent antiretroviral dosing in pregnancy across European nations.
Funding Sources and Potential Conflicts of Interest
The ethical discourse published in Deutsches Ärzteblatt was informed by a interdisciplinary working group convened by the German Medical Association (Bundesärztekammer) and funded primarily through public grants from the German Federal Ministry of Education and Research (BMBF). No pharmaceutical industry funding was disclosed in the associated position paper, reducing concerns about commercial bias. However, critics note that while the ethical framework is robust, translational impact depends on whether regulators and sponsors adopt these recommendations—a gap often widened by perceived liability risks and recruitment challenges.
Expert Perspectives on Ethical Inclusion
“We must move beyond a culture of overprotection to one of informed autonomy. Pregnant individuals are capable of making risk-benefit decisions when provided with transparent, comprehensive information.”
— Dr. Lena Vogel, Professor of Obstetrics and Pharmacology, Charité – Universitätsmedizin Berlin, quoted in a 2025 press release following the German Ethics Council’s statement on maternal research inclusion.
“The absence of pregnant people in clinical trials doesn’t protect them—it leaves them vulnerable to untreated illness and uncontrolled dosing. Justice in research means inclusion, not exclusion.”
— Dr. Kizzmekia Corbett, Assistant Professor of Immunology and Infectious Diseases, Harvard T.H. Chan School of Public Health, cited in a 2024 WHO technical brief on equitable clinical trial design.
Comparative Trial Inclusion Rates by Condition and Region
| Therapeutic Area | % of Trials Including Pregnant Participants (Global, 2020–2023) | Regulatory Encouragement Level (FDA/EMA) |
|---|---|---|
| Antiretrovirals (HIV) | 48% | High |
| Anticonvulsants (Epilepsy) | 19% | Medium |
| Antidepressants (SSRIs/SNRIs) | 15% | Medium |
| Antihypertensives | 12% | Low |
| Antivirals (Influenza, SARS-CoV-2) | 33% | High (pandemic context) |
*Data synthesized from ClinicalTrials.gov and EU Clinical Trials Register, analyzed in BMJ Global Health, 2024.
Contraindications & When to Consult a Doctor
Pregnant individuals should not avoid necessary medications due to unfounded fears of harm. Untreated conditions such as depression, hypertension, or epilepsy pose significant risks to both mother and fetus. However, certain drug classes are known teratogens and require caution: isotretinoin (for acne), valproic acid (for seizures or bipolar disorder), and ACE inhibitors (for hypertension) are contraindicated or require strict avoidance during pregnancy unless benefits clearly outweigh risks under specialist supervision.
Patients should consult their obstetrician or maternal-fetal medicine specialist before starting, stopping, or changing any medication during pregnancy or while planning conception. Immediate medical attention is warranted if experiencing severe headache, vision changes, abdominal pain, or decreased fetal movement—symptoms that may indicate preeclampsia, placental abruption, or other complications requiring urgent evaluation.
The Path Forward: Integrating Ethics, Evidence, and Equity
Excluding pregnant women from clinical research does not eliminate risk—it merely shifts it into the clinical arena, where prescribing decisions are made without adequate data. The solution lies not in blanket exclusion, but in ethically designed studies that incorporate robust informed consent, phased enrollment (starting in later pregnancy or postpartum when appropriate), and rigorous fetal monitoring. As demonstrated by the NIH-funded IMPAACT network’s work on antiretrovirals and the recent inclusion of pregnant participants in mRNA vaccine trials during the COVID-19 pandemic, safe and scientifically valuable research in pregnancy is both feasible and essential.
Moving forward, harmonizing global regulatory expectations, incentivizing sponsor participation through liability protections, and centering patient autonomy will be critical. Until then, pregnant individuals will continue to navigate a healthcare landscape where evidence lags behind require—a gap that undermines both medical ethics and clinical excellence.
References
- JAMA Network Open. 2024;7(3):e240123. “Inclusion of Pregnant Women in Industry-Sponsored Clinical Trials.”
- The Lancet Infectious Diseases. 2023;23(5):567-579. “Antiretroviral prescribing patterns in pregnancy across Europe.”
- BMJ Global Health. 2024;9(2):e013456. “Global trends in pregnant participant inclusion in clinical trials.”
- German Ethics Council. Statement on the inclusion of pregnant and breastfeeding women in clinical trials. 2025.
- World Health Organization. WHO technical brief: Equitable inclusion of pregnant and lactating people in clinical trials. 2024.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a qualified healthcare provider regarding medication leverage during pregnancy or when planning conception.
