Union of http://hl7.org/fhir/ValueSet/ucum-vitals-common and http://phinvads.cdc.gov/fhir/ValueSet/2.16.840.1.114222.4.11.7123

This is the ValueSet that contains all the codes in Vital Signs Units (http://hl7.org/fhir/ValueSet/ucum-vitals-common) and Onset Labor (NCHS) (http://phinvads.cdc.gov/fhir/ValueSet/2.16.840.1.114222.4.11.7123). E.g. what you have to deal with if you get resources containing codes in either of them

CodeSystem