ClinicalTrials.gov serves as an essential public registry and search tool for people interested in clinical trial participation and for researchers studying the evidence base. The site lists more than 600,000 studies and attracts over 3 million visitors each month. Users can filter trials by age, sex, diagnosis, and ZIP code, making it a central resource for matching patients to studies and for characterizing trial composition, publication bias, and representativeness.
Federal law has required the registration of most Phase 2 to Phase 4 drug trials on ClinicalTrials.gov since late 2007. Clinicians advising patients and researchers seeking to understand what trials have been conducted commonly rely on the site’s searchable records and structured fields.
Despite the site’s breadth and filtering tools, ClinicalTrials.gov does not provide structured, searchable data indicating whether trials enroll pregnant or lactating people. That absence hinders patients who are pregnant or breastfeeding from finding trials for which they might be eligible. It also limits clinicians’ ability to advise those patients and constrains researchers who want to quantify how often these populations have been included in studies.
The lack of a dedicated field in the participation eligibility module means that information about pregnancy and lactation eligibility is often buried in free-text eligibility criteria or omitted entirely, preventing straightforward identification and aggregation.
The authors propose adding a specific field within ClinicalTrials.gov’s participation eligibility criteria module that explicitly flags whether a study enrolls pregnant people, lactating people, or both. They further recommend that, if a trial does enroll these populations, the registry include a data element reporting how many pregnant and/or lactating participants were actually enrolled.
This proposal is framed as a straightforward addition to the registry’s structured data model rather than a new statutory obligation. The suggested field would make eligibility information machine-readable and searchable, allowing users to filter trials by pregnancy and lactation status the same way they now filter by age, sex, diagnosis, or location.
Adding a pregnancy and lactation checkbox would have several practical effects:
It would make trials easier for pregnant and lactating people to identify, improving access to information about potential participation.
Clinicians advising reproductive-age patients could more readily find appropriate trials and give evidence-based guidance about study options.
Researchers and policymakers could track how many trials include pregnant and/or lactating people and quantify enrollment, aiding assessments of trial composition, representativeness, and gaps in the evidence.
Simple, structured reporting of enrollment counts for pregnant and lactating participants would enable accurate aggregation of data across studies, rather than relying on inconsistent free-text descriptions.
The authors present this change as a practical step to increase transparency and usability of the registry for populations that are currently hard to identify within trial listings.
The article notes the existing legal framework that resulted in widespread registration of drug trials: federal law has required registration of most Phase 2–4 drug trials on ClinicalTrials.gov since late 2007. The proposed checkbox is described as a technical improvement to the site’s data fields and search functionality rather than a revision to those registration requirements.
No implementation timeline, technical specification, or policy rollout plan was reported in the source. The article does not provide details about who would be responsible for adding the field, how existing records would be retrofitted, or whether registry submitters would be required to populate the new field for past studies.
ClinicalTrials.gov is a high-traffic, legally mandated registry that already supports filtering by multiple patient attributes. Because the site currently lacks structured data indicating whether trials enroll pregnant or lactating people, the authors argue for adding a dedicated checkbox in the participation eligibility module and a corresponding enrollment-count field. This modest, data-focused change would make trials easier to find for pregnant and lactating individuals, help clinicians advise patients, and allow researchers to track inclusion of these populations across the body of registered studies.
The recommendation is presented as a simple, actionable website change; the source does not report further technical or policy details about implementation.
Authors and affiliations cited in the source: Alyssa Bilinski (Peterson family assistant professor of health services, policy, and practice and of biostatistics, Brown University School of Public Health), Haley Sullivan (faculty fellow, Brown University School of Public Health), and Anne C.C. Lee (Levinger family professor of pediatrics, Warren Alpert Medical School of Brown University).