In the laboratory routine a sequence of samples or a relation between multiple samples is needed.
In the current data model there is no information about relations between samples, in particular whether a primary sample or secondary sample is meant.

 
See https://www.x-ehealth.eu/wp- content/uploads/2022/09/D5.3- Laboratory-Requests-and-Reports- guideline-and-functional- specifications.pdf

Chapter 5.2.2.6.3.1

 
We propose to add the data element "Parent" from the original FHIR Specimen resource.

This element is used to refer to „Specimen from which this specimen originated“. 
Additionally a narrative text data field for differentiation between primary or secondary samples might be useful.

– Submitted by The Federal Institute for Drugs and Medical Devices (Bundesinstitut für Arzneimittel und Medizinprodukte, BfArM)