Setting up mother-infant pair lactation studies with biobanking for research according to regulatory requirements

Within the ConcePTION project we set out to design two mother-infant pair studies collecting breast milk and plasma from the mother and plasma from the infant (for metformin and prednisolone) in order to demonstrate the premises and conditions for investigating potential drug transfer in association with breastfeeding. It is essential that the information from lactation studies is trustworthy and fulfils regulatory standards and requirements for the results to be fit for label. In this paper we describe the premises and conditions for mother-infant pair studies and biobanking for research of collected samples as laid down in regulatory requirements. The studies on metformin are still ongoing. At the time of the study (June 2025), 18 participants had been included in the metformin study and 20 in the prednisolone study. Evidence for the use of medicines in association with breastfeeding is urgently needed, both for already approved and used drugs, and for the development of new drugs. Based on our experiences within the IMI-ConcePTION project, we have described the premises for mother-infant pair studies to be adhered to.