There is Doha Clinic near you, it's one of two hospitals all of my friends are using. Another one is Al Ahli hospital, but it is far from al sadd.
In Doha Clinic best ob-gyns are Dr. Tabassum or Dr. Salma, both are women. I was pregnant end of 2007 - start of 2008, and I have given birth in Doha Clinic, my check - ups were with doctor Tabassum. First visit costs around 150 QR, than it gets around 80 for check up, but for ultrasound you need to pay separatly.