Collection of cord and maternal blood at delivery allows for calculation of cord-to-maternal blood drug concentration ratio that assists with understanding placental transfer, fetal exposure and neonatal safety. While this provides important data for drug labelling and usage guidelines in pregnant women, it is often not feasible within the context of a larger phase 3 or 4 trial geared towards non-pregnant populations.  

Washout sampling¹ performed in the first 3–5 days of the infant’s life can be helpful to understand how medications or substances are metabolized and excreted in neonates. This can have important dosing implications for this age group and help ensure safe and effective treatments for this population. Again, while this provides important data for drug labelling and usage guidelines in neonates, it is often not feasible within the context of a larger phase 3 or 4 trial geared towards non-pregnant populations.  

¹ PK samples taken during the drug‐free (“wash‑out”) period to characterize elimination of a drug (or prior drug exposure) in neonates, without interference from new doses.