Post-Marketing Surveillance and Precision Pharmacovigilance in Pregnant, Postpartum and Breastfeeding Patients: Mapping Outcomes to Enhance Drug Safety

Background/Objectives: Pregnant, postpartum, and breastfeeding individuals are frequently underrepresented or excluded from pre-approval clinical trials, making pharmacovigilance and post-marketing surveillance essential sources of evidence for drug safety in these populations. At the same time, precision medicine is reshaping therapeutic decision-making through the integration of pharmacogenomic, molecular, clinical, and digital health data. Methods: This narrative review examined post-marketing evidence sources, clinically relevant outcome domains, precision medicine tools, illustrative case studies, and implementation challenges in pregnancy, postpartum, and breastfeeding care. Step one addressed the limitations of current pharmacovigilance and the principal sources of post-marketing safety data in pregnancy, postpartum, and breastfeeding contexts, including spontaneous reporting systems, pregnancy exposure registries, observational studies, regulatory frameworks, and Post-Authorisation Safety Studies. Step two defined the clinically relevant outcome domains. Step three examined precision medicine tools, including pharmacogenomics, biomarker-guided risk stratification, model-informed pharmacokinetic approaches, and digital health monitoring. Step four considered implementation. Examples were classified by evidence maturity as established in clinical or regulatory practice, supported by preliminary evidence, or conceptual. Results: Traditional pharmacovigilance in pregnancy remains strongly focused on congenital malformations, while other clinically relevant domains, including maternal outcomes, breastfeeding-related exposure, and long-term child development, are less systematically captured. Precision medicine tools may strengthen pharmacovigilance by improving exposure assessment, identifying susceptible subgroups, and supporting more individualised interpretation of safety signals; however, current evidence is often limited. Conclusions: Embedding structured outcome domains, pharmacogenomic data, pharmacokinetic modelling, and digital monitoring into post-marketing safety frameworks may improve the detection, interpretation, and clinical relevance of adverse drug reactions enabling precision pharmacovigilance.