Uterine size-date discrepancy, third trimester

This code indicates a significant difference between the actual size of the uterus (as determined by fundal height or ultrasound) and the expected size based on the gestational age of the pregnancy during the third trimester. This discrepancy can manifest as either the uterus being larger or smaller than anticipated for the given dates.

Use this code when the obstetrician documents a uterine size-date discrepancy in the third trimester, requiring further investigation or management. Documentation should clearly state the trimester and the nature of the discrepancy (e.g., "fundal height 30 cm at 34 weeks gestation" or "uterus measures small for dates at 36 weeks").

• Always specify the trimester. Codes exist for first and second trimesters.
• Do not use this code if the discrepancy is due to a known multiple gestation; instead, code for the multiple gestation.
• Code any underlying cause for the discrepancy (e.g., polyhydramnios, oligohydramnios, intrauterine growth restriction, macrosomia) as a secondary diagnosis.