Personally for me i rather stick to one person than to change midway. Or maybe I dont like the idea of repeating my history etc to another gynae.
I had initially made apptment wif nuh gynae (the apptment was pretty late, like after those nipt tests). I was with a private gynae coz they suggested i do my scan n test outside while waiting for this apptment.
Since i waited and more n more problems start surfacing, i see no point in changing gynae.
I really think it depends on your comfort level and $ also.