{
  "resourceType": "StructureDefinition",
  "id": "ncdhc-observation-fetal-gestational-age",
  "url": "http://hl7.org.au/fhir/ch/v1/StructureDefinition/ncdhc-observation-fetal-gestational-age",
  "version": "dv1.0.0",
  "name": "NCDHC Fetal Gestational Age Observation Profile",
  "title": "NCDHC Fetal Gestational Age Observation",
  "status": "draft",
  "date": "2020-01-10",
  "publisher": "National Children's Digital Health Collaborative (NCDHC)",
  "copyright": "Copyright © 2019 Australian Digital Health Agency - All rights reserved. This content is licensed under a Creative Commons Attribution 4.0 International License. See https://creativecommons.org/licenses/by/4.0/",
  "description": "fetal gestational age",
  "purpose": "fetal gestational age",
  "fhirVersion": "3.0.2",
  "kind": "resource",
  "abstract": false,
  "type": "Observation",
  "baseDefinition": "http://hl7.org.au/fhir/ch/v1/StructureDefinition/ncdhc-observation-base",
  "derivation": "constraint",
  "differential": {
    "element": [
      {
        "id": "Observation",
        "path": "Observation",
        "short": "NCDHC Tobacco Use Assessment Observation Profile"
      },
      
      {
        "id": "Observation.code",
        "path": "Observation.code",
        "short": "Drug usage during gestation period",
        "patternCodeableConcept": {
          "coding": [
            {
              "system": "http://snomed.info/sct",
              "code": "57036006"
            }
          ]
        },
        "mustSupport": true
      },
      {
        "id": "Observation.subject",
        "path": "Observation.subject",
        "short": "Reference to the Mother Patient",
        "type": [
          {
            "code": "Reference",
            "targetProfile": "http://hl7.org.au/fhir/ch/v1/StructureDefinition/ncdhc-patient-expectant-mother"
          }
        ]
      },
      {
        "id": "Observation.effectiveDateTime:effectiveDateTime",
        "path": "Observation.effectiveDateTime",
        "sliceName": "effectiveDateTime",
        "short": "Date when amniotic fluid was assessed"
      },
      {
        "id": "Observation.performer",
        "path": "Observation.performer",
        "short": "Person who is clinically responsible for the undetaking of the assessment"
      },
      {
        "id": "Observation.value[x]:valueQuantity",
        "path": "Observation.valueQuantity",
        "sliceName": "valueQuantity",
        "short": "Illicit drug usage during gestation",
        "type": [
          {
            "code": "Quantity"
          }
        ],
        "mustSupport": true
      },
      {
        "id": "Observation.value[x]:valueQuantity.value",
        "path": "Observation.valueQuantity.value",
        "min": 1
      },
      {
        "id": "Observation.value[x]:valueQuantity.unit",
        "extension": [
          {
            "url": "http://hl7.org/fhir/StructureDefinition/elementdefinition-translatable",
            "valueBoolean": true
          }
        ],
        "path": "Observation.valueQuantity.unit",
        "fixedString": "days"
      },
      {
        "id": "Observation.value[x]:valueQuantity.system",
        "path": "Observation.valueQuantity.system",
        "fixedUri": "http://unitsofmeasure.org"
      },
      {
        "id": "Observation.related.target",
        "path": "Observation.related.target",
        "type": [
          {
            "code": "Reference",
            "targetProfile": "http://hl7.org/fhir/StructureDefinition/Observation"
          },
          {
            "code": "Reference",
            "targetProfile": "http://hl7.org/fhir/StructureDefinition/QuestionnaireResponse"
          }
        ]
      }
    ]
  }
}