WHO moves to close a long-standing TB evidence gap in pregnancy and lactation
WHO has launched a new TB in pregnancy and lactation research toolkit, a practical online resource aimed at improving how pregnant and lactating women are included in tuberculosis research. The release targets a familiar problem in infectious disease trials: the very people most likely to need clear guidance are often the least represented in the evidence base.
Pregnancy changes physiology in ways that matter for tuberculosis drugs and vaccines. Blood volume expands, renal clearance shifts, body composition changes, and lactation adds another layer of pharmacokinetic uncertainty. When those variables are not studied directly, dosing assumptions become fragile, and clinicians are forced to extrapolate from nonpregnant adults. In TB, where treatment courses can be long and drug combinations complex, those gaps can affect both maternal care and infant safety.
The new toolkit is designed for researchers, trial sponsors, ethics committees, regulators, and other stakeholders involved in TB drug and vaccine development. Its purpose is practical rather than symbolic: to make earlier and optimal inclusion of pregnant and lactating women easier to plan, justify, and execute.
A direct consequence is better evidence for bedside decisions that currently rely on inference. For mothers with TB, inference is not enough.
Practical guidance for study design, ethics, and regulatory review
The toolkit brings together guidance across the major pressure points that have historically limited enrollment of pregnant and lactating women. It addresses ethical considerations and community engagement, preclinical issues relevant to TB research, trial design, pharmacokinetics during pregnancy, postpartum and lactation, outcome measures, sample size planning, recruitment and retention strategies, regulatory aspects, TB vaccine trial considerations, and surveillance and registries.
Each of those domains matters because exclusion often begins early in the research pipeline. Sponsors may avoid enrollment because of safety uncertainty. Ethics committees may hesitate when fetal or infant exposure is possible. Regulators may face incomplete datasets. The result is a circular problem in which lack of data justifies continued lack of data.
The toolkit is intended to break that cycle by offering concrete ways to structure studies rather than relying on broad statements of caution. WHO says the resource also includes case studies and curated materials drawn from completed and ongoing research initiatives, giving users examples of how inclusion can be handled in real-world settings.
For tuberculosis, this has special importance because the disease burden does not pause during pregnancy or breastfeeding. Delay in generating evidence means delay in access to better prevention and treatment strategies for both women and their infants.
Why TB research has lagged behind for pregnant and lactating women
Pregnant and lactating women have historically been excluded from TB drug and vaccine trials, leaving major evidence gaps around safety, pharmacokinetics, dosing, and effectiveness. Those gaps are not academic. They directly affect whether clinicians can select regimens with confidence, whether vaccines can be advanced into programs that include women of reproductive age, and whether infants are protected from avoidable exposure or undertreatment.
WHO framed the launch as part of a broader effort to accelerate progress toward ending TB for everyone. Dr Tereza Kasaeva, director of WHO’s Department for HIV, Tuberculosis, Hepatitis and Sexually Transmitted Infections, said pregnant and lactating women remain underrepresented in TB research, creating critical evidence gaps that delay access to innovations and optimal care. Her remarks align with a persistent problem across global clinical research: populations that are excluded for caution’s sake are later left with less certain care.
The research challenge is especially sharp for TB vaccines. Vaccine trials often have to balance immunogenicity, maternal safety, fetal considerations, and infant outcomes, all while working within stringent regulatory expectations. For drugs, the key questions often turn on exposure, metabolism, and whether standard adult dosing actually delivers the intended effect during pregnancy or lactation. Without direct study, either underdosing or unnecessary dose escalation can become a risk.
Built on a global consensus process from 2024 and 2025
WHO developed the toolkit as a follow-up to a global consensus process on the early and optimal inclusion of pregnant and lactating women in TB research. Working groups and consultations held during 2024 and 2025 brought together experts from all WHO regions to identify barriers and practical solutions for stronger evidence generation in this population.
That process culminated in the August 2025 publication of Optimal and early inclusion of pregnant and lactating women in tuberculosis research and the accompanying call to action, Accelerating research to end tuberculosis in pregnant and lactating women. The toolkit was identified as one of the priority actions in that call to action, turning consensus language into an operational resource.
The timing reflects a larger shift in clinical trial ethics and design. Instead of treating pregnancy and lactation as afterthoughts, the research framework now pushes toward planned inclusion from the outset, with the necessary safeguards built in rather than added later. In practical terms, that means trial teams can think about exposure, follow-up, safety monitoring, and infant outcomes before a protocol is finalized.
How the new toolkit fits into WHO’s broader research portal
The TB toolkit complements WHO’s broader knowledge portal on the inclusion of pregnant and lactating women in clinical trials across health conditions. The wider portal offers general principles and approaches, while the TB-specific toolkit translates those principles into the details that matter for tuberculosis research.
That distinction is important because TB research poses special questions that generic guidance cannot fully answer. Drug combinations, prolonged treatment duration, vaccine development, and the need for disease surveillance all raise issues that require disease-specific planning. By focusing on TB, the toolkit gives users a more workable path from policy principle to study protocol.
The launch does not resolve the evidence gap by itself. It provides the structure needed to reduce future gaps, and it may help normalize the idea that exclusion is not a neutral default. In diseases where maternal treatment decisions can affect both woman and child, study design shapes clinical care long before a paper reaches the bedside.
For now, the key issue is whether research programs, sponsors, and regulators adopt the toolkit quickly enough to change how upcoming TB studies are built. The resource now exists; the next test is whether it changes enrollment decisions, protocol design, and the pace at which pregnancy- and lactation-specific TB data finally accumulate.