you can choose pregnancy health care provider on the basis of following factors-

experience- If you are choosing a health care providing agency, then you should check how old it is.
facilities- what facilities they are providing to a pregnant women and what is the average time duration of their services. for eg. during labour pain, in how much time ambulance can come.

work experience of the employees like doctors and nurses who are working for this agency. How many years of experience they have.
Is this health agency is registered or carrying all valid required certificate or not.
you can take experience of their old patients. olshoppers.com