Gestational diabetes mellitus in childbirth, diet controlled

This code signifies gestational diabetes mellitus (GDM) diagnosed during pregnancy, specifically when the patient is in the process of childbirth. The condition is managed solely through dietary modifications, without the need for insulin or oral hypoglycemic agents. It reflects the presence of GDM during the peripartum period.

Apply this code when a pregnant patient with diet-controlled GDM is admitted for delivery. Documentation should clearly state "gestational diabetes," "diet controlled," and indicate the patient is in labor or undergoing a planned C-section. This code is appropriate for the encounter where the birth occurs.

• Always sequence this code as a secondary diagnosis, following the code for the delivery (e.g., O80, O82).
• Do not use this code if the patient is on insulin or oral medications for GDM; refer to codes O24.414 or O24.419, respectively.
• Ensure the medical record explicitly states "diet controlled" to support the use of this specific subcategory.