I found that you could get maternity coverage with an indemnity policy. You will have a $$ cap on how much will be covered. It can be combined with other coverage.
I have heard that you can contact your current ins, company and ask for rates to stay on their policy after COBRA ends.
See if you can find a hospital price comparison tool online (there is one for my state, maybe there is one for yours too). Some hospitals are less expensive than others, maybe you can find an OB you like who works out of a less expensive hospital.
Think of any group affiliation you have and see if they have any insurance policies available to them. (like a credit union, a religious organization, the chamber of commerce, just think GROUP, a crazy example from my own life, I found many leads from the Artist's Health Insurance Resource Center, ahirc.org )
It was 2 years ago that I did my insurance research and I know a lot has changed , HTH