What is the icd 9 code for a 24 year old woman at 28 weeks gestation has hypothyroidism?

648.13, 244.9
RATIONALE: The coder will locate the main term "Hypothyroidism" in the Alphabetical Index. Then the coder will locate the sub term "complicating pregnancy, childbirth, or puerperium" and the code is 648.1. In verifying this code, the coder will find the need to select a fifth digit. The fifth digit "3" states "antepartum condition or complication." Since the woman is at 28 weeks and there is no mention of having delivered, we choose this fifth digit and the correct code is 648.13.
After locating the code for hypothyroidism complicating pregnancy, the coder should make note of the notation within the 647 category which says "Use additional code(s) to further specify complication. This means that the coder must also code the mother's condition of hypothyroidism. Since we are not told of any specific condition, we have to code it as unspecified which is code 244.9.