foetalAge on pregnancy definition

[Busfi3ld]

Hi, quick question regarding the foetalAge on the Pregnancy diagnosis ep. icarReproPregnancyCheckEventResource

Is this the foetal age when the pregnancy diagnosis took place or the foetal age when the data is pulled?
Many thanks MB

icarReproPregnancyCheckEventResource
"description": "Pregnancy diagnosis or check event.",

"allOf": [{
"$ref": "../resources/icarAnimalEventCoreResource.json"
},
{
"type": "object",

  "properties": {
    "method": {
      "$ref": "../enums/icarReproPregnancyMethodType.json",
      "description": "Method by which diagnosis was carried out."
    },
    "result": {
      "$ref": "../enums/icarReproPregnancyResultType.json",
      "description": "Result - unknown, empty, pregnant."
    },
    **"foetalAge": {
      "type": "integer",
      "description": "Assessed age of the foetus or length of the pregnancy (in days)."**
    },

[cookeac]

The foetal age and other attributes are those observed at the event date. The data might be retrieved years later, so foetal age should not be expected to adjust on this basis