Your doctor will ask about your past health. They'll give you a physical exam. They may be able to diagnose chorioamnionitis just by your symptoms. You may also need a lab test to check for infection.
Your doctor may suggest a test called amniocentesis. This test isn't routinely done for chorioamnionitis, but may be recommended when chorioamnionitis is suspected outside of labor. During this test, your doctor uses a needle to take a small amount of amniotic fluid for testing.