<Observation xmlns="http://hl7.org/fhir">
  <id value="PregnancyDuration-example" />
  <meta>
    <profile value="http://fhir.nl/fhir/StructureDefinition/nl-core-observation" />
    <profile value="http://nictiz.nl/fhir/StructureDefinition/zib-Pregnancy-PregnancyDuration" />
  </meta>
  <extension url="http://nictiz.nl/fhir/StructureDefinition/observation-focusSTU3">
    <valueReference>
      <reference value="Condition/wouden-zwanger1" />
      <display value="Wouden zwangerschap 1" />
    </valueReference>
  </extension>
  <status value="final" />
  <code>
    <coding>
      <system value="http://snomed.info/sct" />
      <code value="57036006" />
      <display value="Fetal gestational age" />
    </coding>
  </code>
  <subject>
    <reference value="Patient/XXX-VDWOUDEN" />
    <display value="Patient van der Wouden" />
  </subject>
  <context>
    <reference value="EpisodeOfCare/wouden-dossier-zwanger1" />
    <display value="zwangerschap Wouden 1" />
  </context>
  <effectiveDateTime value="2021-05-06" />
  <performer>
    <reference value="Practitioner/example" />
    <display value="Vera de Los" />
  </performer>
  <valueQuantity>
    <value value="12" />
    <system value="http://unitsofmeasure.org" />
    <code value="wk" />
  </valueQuantity>
</Observation>