```xml
<?xml version="1.0" encoding="UTF-8" standalone="yes"?>
<ns3:query_definition xmlns:ns2="http://www.i2b2.org/xsd/cell/crc/psm/1.1/" xmlns:ns4="http://www.i2b2.org/xsd/cell/crc/psm/analysisdefinition/1.1/" xmlns:ns3="http://www.i2b2.org/xsd/cell/crc/psm/querydefinition/1.1/">
    <query_name>(t) DiagnosesCirculatory sysDigestive systeEvents of pregn@11:25:36</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>1</hlevel>
            <item_name>Diagnoses</item_name>
            <item_key>\\i2b2_DIAG\i2b2\Diagnoses\</item_key>
            <item_icon>FA</item_icon>
            <tooltip>Diagnoses</tooltip>
            <class>ENC</class>
            <item_is_synonym>false</item_is_synonym>
        </item>
    </panel>
    <subquery_constraint>
        <first_query>
            <query_id>Event 1</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </first_query>
        <operator>LESS</operator>
        <second_query>
            <query_id>Event 2</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </second_query>
    </subquery_constraint>
    <subquery_constraint>
        <first_query>
            <query_id>Event 1</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </first_query>
        <operator>LESS</operator>
        <second_query>
            <query_id>Event 3</query_id>
            <join_column>STARTDATE</join_column>
            <aggregate_operator>FIRST</aggregate_operator>
        </second_query>
    </subquery_constraint>
    <subquery>
        <query_id>Event 1</query_id>
        <query_type>EVENT</query_type>
        <query_name>Event 1</query_name>
        <query_timing>SAMEINSTANCENUM</query_timing>
        <specificity_scale>0</specificity_scale>
        <panel>
            <panel_number>1</panel_number>
            <panel_timing>SAMEINSTANCENUM</panel_timing>
            <panel_accuracy_scale>100</panel_accuracy_scale>
            <invert>0</invert>
            <total_item_occurrences>1</total_item_occurrences>
            <item>
                <hlevel>2</hlevel>
                <item_name>Circulatory system</item_name>
                <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Circulatory system (390-459)\</item_key>
                <item_icon>FA</item_icon>
                <tooltip>Diagnoses \ Circulatory system</tooltip>
                <class>ENC</class>
                <item_is_synonym>false</item_is_synonym>
            </item>
        </panel>
    </subquery>
    <subquery>
        <query_id>Event 2</query_id>
        <query_type>EVENT</query_type>
        <query_name>Event 2</query_name>
        <query_timing>SAMEINSTANCENUM</query_timing>
        <specificity_scale>0</specificity_scale>
        <panel>
            <panel_number>1</panel_number>
            <panel_timing>SAMEINSTANCENUM</panel_timing>
            <panel_accuracy_scale>100</panel_accuracy_scale>
            <invert>0</invert>
            <total_item_occurrences>1</total_item_occurrences>
            <item>
                <hlevel>2</hlevel>
                <item_name>Digestive system</item_name>
                <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Digestive system (520-579)\</item_key>
                <item_icon>FA</item_icon>
                <tooltip>Diagnoses \ Digestive system</tooltip>
                <class>ENC</class>
                <item_is_synonym>false</item_is_synonym>
            </item>
        </panel>
    </subquery>
    <subquery>
        <query_id>Event 3</query_id>
        <query_type>EVENT</query_type>
        <query_name>Event 3</query_name>
        <query_timing>SAMEINSTANCENUM</query_timing>
        <specificity_scale>0</specificity_scale>
        <panel>
            <panel_number>1</panel_number>
            <panel_timing>SAMEINSTANCENUM</panel_timing>
            <panel_accuracy_scale>100</panel_accuracy_scale>
            <invert>0</invert>
            <total_item_occurrences>1</total_item_occurrences>
            <item>
                <hlevel>2</hlevel>
                <item_name>Events of pregnancy</item_name>
                <item_key>\\i2b2_DIAG\i2b2\Diagnoses\Events of pregnancy (630-677)\</item_key>
                <item_icon>FA</item_icon>
                <tooltip>Diagnoses \ Events of pregnancy</tooltip>
                <class>ENC</class>
                <item_is_synonym>false</item_is_synonym>
            </item>
        </panel>
    </subquery>
</ns3:query_definition>

```

I want to find all patients who have been diagnosed with a circulatory system disorder (codes 390-459) and a digestive system disorder (codes 520-579) at any time, with no specific time frame constraint, and who also have had an event related to pregnancy (codes 630-67) at any time, with no specific time frame constraint, where the diagnosis of the circulatory system disorder occurred before the digestive system disorder, and the digestive system disorder occurred before the pregnancy-related event.