<Observation xmlns="http://hl7.org/fhir"><id value="date-lastmp"/><status value="final"/><category><coding><system value="http://terminology.hl7.org/CodeSystem/observation-category"/><code value="survey"/><display value="Survey"/></coding><text value="AOE"/></category><code><coding><system value="http://loinc.org"/><code value="8665-2"/><display value="Last menstrual period start date"/></coding><text value="Last menstrual period start date"/></code><subject><reference value="Patient/pat2"/></subject><effectiveDateTime value="2016-01-24"/><valueDateTime value="2016-12-30"/></Observation>