postpone? yes
There are some cases when you absolutely HAVE to postpone your CP interview.
In my case, my CP interview was scheduled for January 2002, and we were expecting our baby in Jan 2002. So there was no way we could fly from the US to the consular post to attend the CP interview. So my lawyer requested the consulate to reschedule my interview.
I don't know the actual mechanics (what form to file etc.) I just know that it is possible. Talk to your lawyer, or maybe the folks here on the boards will be able to tell you.
Good luck
vtcat