```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns4:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/">
    <query_name>FETAL B-Princip@12:23:27</query_name>
    <query_timing>ANY</query_timing>
    <specificity_scale>0</specificity_scale>
    <panel>
        <panel_number>1</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>5</hlevel>
            <item_name>FETAL BLOOD MCV (LOINC:11272-2)</item_name>
            <item_key>\\i2b2_LABS\i2b2\Labtests\LAB\(LLB53) Hematology\(LLB57) Complete Blood Count\MCV\LOINC:11272-2\</item_key>
            <item_icon>LA</item_icon>
            <tooltip>Labtests \ Hematology \ Complete Blood Count \ MCV (Group:MCV) \ Fetal Blood MCV (LOINC:11272-2)</tooltip>
            <class>ENC</class>
            <constrain_by_value>
                <value_operator>EQ</value_operator>
                <value_constraint>H</value_constraint>
                <value_type>FLAG</value_type>
            </constrain_by_value>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <panel>
        <panel_number>2</panel_number>
        <panel_timing>ANY</panel_timing>
        <panel_accuracy_scale>100</panel_accuracy_scale>
        <invert>0</invert>
        <total_item_occurrences>1</total_item_occurrences>
        <item>
            <hlevel>1</hlevel>
            <item_name>Factors influencing health status and contact with health services (z00-z99)</item_name>
            <item_key>\\ICD10_ICD9\Diagnoses\(Z00-Z99) Fact~rmj9\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Diagnoses \ Factors influencing health status and contact with health services (z00-z99)</tooltip>
            <class>ENC</class>
            <constrain_by_modifier>
                <modifier_name>Principal Diagnosis</modifier_name>
                <modifier_key>\\ICD10_ICD9\Principal Diagnosis\</modifier_key>
                <applied_path>\Diagnoses\(Z00-Z99) Fact~rmj9\%</applied_path>
            </constrain_by_modifier>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
</ns4:query_definition>

```

I want to find all patients with a Fetal Blood MCV (LOINC:1272-2) lab test result in the hematology panel and who have a principal diagnosis in the Factors influencing health status and contact with health services (z0-z9) category.