Safety of Postpartum Herbal Medicine in Primary Care Korean Medicine Clinics: Protocol for a Prospective, Multicenter, Registry-Based Observational Study

BACKGROUND: Postpartum conditions significantly affect maternal and infant health. In South Korea, herbal medicine is commonly used for postpartum care in Korean medicine, but safety data remain limited. This study outlines a multicenter Korean medicine clinic registry designed to investigate treatment patterns and adverse events (AEs) associated with postpartum herbal medicine use. This primary care, practice-based research network registry will inform clinical decision-making and pharmacovigilance in postpartum care, supporting the quality and safety of care and guidance for comedication monitoring across community clinics. OBJECTIVE: This study aims to establish a multicenter registry to investigate AEs and treatment patterns associated with postpartum herbal medicine use in Korean medicine clinics. METHODS: This prospective observational registry will enroll postpartum patients receiving herbal medicine treatment from 15 Korean medicine clinics between July 2024 and June 2027, with a target sample size of 1000 participants. Patients within 6 months postpartum receiving herbal medicine will be included. Data will be collected for up to 8 weeks, including demographic information, medical history, herbal medicine prescriptions, AEs, and concomitant medication use. AEs are self-reported by patients, and causality is assessed using the World Health Organization Uppsala Monitoring Centre system and the Naranjo algorithm. Data collection and entry will follow standard operating procedures. RESULTS: The registry was registered with the Clinical Research Information Service in June 2024 (KCT0009552). Recruitment began in July 2024 across 15 Korean medicine clinics and is planned to continue until June 2027 with a target enrollment of 1000 postpartum patients. CONCLUSIONS: This study represents the first large-scale, multicenter registry examining herbal medicine use during the postpartum period in Korean medicine clinics. By systematically collecting real-world data on AEs associated with postpartum herbal medicine use, we aim to establish a comprehensive safety database for individual herbal medicine and constituent herbs. The findings may support pharmacovigilance of herbal medicine and improve postpartum care outcomes for mothers and infants. TRIAL REGISTRATION: WHO ICTRP KCT0009552; https://trialsearch.who.int/?TrialID=KCT0009552. INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID): DERR1-10.2196/87543.