I also used Dr Andersen's practice and they are exceptional. They have 5 doctors and a nurse-midwife on staff - all female, which I liked - and they are wonderful about responding to your needs and concerns.
Its the only ob/gyn I've ever been to that use actual cloth gowns (they launder them in the office = ), and they have different things up on the ceilings to look at. But even more importantly, Dr Andersen has a tremendous amount of experience and is wonderful - her whole staff is.
I found them through a referral and when I talked to my friend here at work, it turned out that Dr Andersen was who had delivered her son - now 20 years old! She has only wonderful things to say about her and the practice as well.
Their telephone is ###-###-#### and their office is 8501 Arlington Blvd., Ste 300 (on the corner of Prosperity and Rt 50) - they are just up the street from Fairfax Hospital (since they are there so often = )
Good luck!