UmbrelLACT Study: Clinical Lactation Study on the Exposure to Medicines Via Human Milk

Every time the mother would normally feed the child, we ask to collect the total milk volume for the feed from both breasts by an electric pump. For each collection, the volume and time will be noted, the container will be inverted and 5 to 10ml of that volume will be transferred in a polypropylene test tube or other tube type depending on the type of compounds (=sample to determine drug concentration in milk) for analysis (max 10% of the collected volume of each feed). The participant decides how the remainder of the collected milk is used. The milk samples will immediately be stored in the refrigerator (4°C) after being labeled. The samples will be collected by one of the investigators within 24 hours, will be transported on ice and frozen at -80°C until analysis.

Blood collection to determine the drug concentration in plasma (6 to 10mL EDTA or other tube type, depending on the type of compound) will be performed at least within 1 hour interval with the first feeding (pumping) after medication intake, and 24 hours after medication intake (with preferable milk collection within 1 hour of blood sampling). The sample label, date and time of sampling will be noted.

Blood collection of the infant to determine systemic exposure of child(1-5% of the total blood volume, according to the FDA guidelines, in an EDTA or other tube type, depending on the type of compound,) will be performed at the same day as the maternal sampling, if parental consent is obtained. The sample label, date and time of sampling will be noted.