Pregnancy management is generally billed under a global fee structure. The exception is when there is a problem (pregnancy related or not) that goes outside the course of a routine visit (not a minor problem). In that case, the global code is not billed and a standard Evaluation/Management visit code is used (99212, 99213, 99214, or 99215).
ICD-9 Codes for Pregnancy
V22.0 Supervision of normal first pregnancy
V22.1 Supervision of other normal pregnancy
V22.2 Pregnant state, incidental
If a problem is found that not directly related to the pregnancy (asthma, strep throat, etc.), an Evaluation/Management code should be used and the ICD-9 for the problem should be listed first and then followed by V22.2 Pregnancy state, incidental.