Fortuntately for my wife and I, the "line was already drawn," so to speak, when we began treating her infertility. We got a referral to an excellent urologist from Norlisa's then OB/GYN, who referred us to excellent reproductive endocrinologists/infertility doctors, who would not try getting my wife pregnant without her seeing the excellent perinatologist they referred her to to treat her hypertension. (I keep using the word, but there is no other way to describe all of them, they are great doctors and people.)
One could always find out about doctors that they can trust through referrals from friends and from doing research. Also, the websites such as nasshp and smfm help to find the type of doctor you're looking for. The quality that distinguished these doctors is that they each took the time to explain throughly what was going on, what is happening in your wife's/twins' bodies, make drawings, show graphs, answer each and every question patiently and to the best of their ability. While you are there, you are the only patient in the room, and there is a doctor/patient relationship where you both want the same thing: the best for your wife and children. None of them ever made us feel like we were asking stupid questions, and they were sensitive and respectful of the fact that we were trusting our lives to them. These doctors are such experts in their field and confident, but not cocky, and would make sure that you left there with peace of mind.
I believe that if a doctor is knowledgeable in his or her area of expertise, they will answer all of your questions. They work with you to achieve the best outcome and illustrate the true meaning of a good doctor/patient relationship and partnership. You learn from them, the questions come naturally while you're with them and you're not afraid to ask, you don't feel intimidated but comfortable in the choice you've made in your physicians.