Ob-Gyn Coding Alert

Test your coding knowledge.  Determine how you would code this situation before looking at the box below for the answer.
Question: If an ob patient has a one-hour blood sugar test that came back abnormal, which diagnosis should I use for the subsequent three-hour glucose test when we won't know what's wrong until the test comes back? Also, should I use pregnancy diagnosis codes?

Michigan Subscriber

Answer: The diagnosis is always the reason for ordering the test, and you use the pregnancy codes only when the condition is complicating the pregnancy or if the condition is a complication of pregnancy. If neither were the case, the code for abnormal test result, 790.2 (abnormal glucose tolerance test), would be correct to use with a secondary diagnosis of V22.2 (pregnant state, incidental). However, it appears that the abnormal glucose levels will be complicating pregnancy, so you can use the ob code first (648.8x, abnormal glucose tolerance, complicating pregnancy, childbirth, or the puerperium) and use 790.2 as the secondary diagnosis for further clarification until the test results give a more definitive condition.