Hi,
As per my knowledge As per CMS guidlines , During The PREGNANCY period Preventive Care service are Not consider , So most of the Dr Will postpone the visit till the Pt get DELIVERED and Billed accodingly,
So Preventive Service rarely Billed with OB-US,
if the patient have any complication she can Bill E/M visit for that treatment with 25 Modifier and OB-US code.
Sri