Ob-Gyn Coding Alert

Question: The patient is pregnant and had an ultrasound due to the fact that she has a long-term use of the prescription drug Metformin. What diagnosis code should I use? My first thought is to use 655.53 (Suspected damage to fetus from drugs affecting management of mother antepartum). Is that correct?

Wyoming Subscriber

Answer: Most studies suggest that Metformin is not associated with an increased risk of birth defects, and some recent trials studying the safety of metformin during pregnancy, mostly when used to treat insulin resistance in women with PCOS, did not show an increased rate of birth defects or complications at birth. 

Because of this, you should ask your physician if he is doing this ultrasound as a routine screening or specifically because he suspects a problem with the fetus. If he does suspect a problem, this should have been noted in the medical note at the time of the encounter. Obviously, you have no specific ICD-9 code for long-term use of a prescribed drug, but if he feels this puts the pregnancy at risk, and currently there are no complaints, you might want to report V23.89 (Other high risk pregnancy) as the reason for the ultrasound.

ICD-10: When your diagnosis system changes, you will us O09.89 (Supervision of other high risk pregnancies) instead.