For DC1 I had GP ante-natal checks only as there was no midwife at the surgery.
First GP I saw (supposedly with ante-natal care skills) had no idea what I meant by an anatomy/anomoly/20 week scan (not standard in my area then, but I wanted one due to family history of heart and kidney issues).
I had to explain to him it was normal in 90% of the UK and meant to be introduced to Glasgow asap. He mused outloud about why it was done at 20 weeks, oh, must be because of the abortion deadline, he said. When is that? 28 weeks, he asked? (This was the week it was in the news as the debate raged on lowering it from 24 weeks and parliament considered it).
Needless to say this didn't inspire confidence in me as a first timer, and though he wrote to the consultant and requested a scan for me I vowed never to see him again for an ante-natal appointment.
I made my next ante-natal appointments with another GP and she was excellent. Did all my checks monthly and was very helpful at referring me on when there were some concerns. Otherwise I just phoned the hospital triage and went in when required.
With DC2 I was under the care of a midwife clinic but saw different mw's every time, some excellent and some less than helpful. Again I attended the hospital for any major queries.
So for me it wasn't the role, GP or MW, that made the difference, but the professionalism, interest and knowledge of the individual.