A.C.
Minnesota Perinatal Physicians specializes in high risk, multiple pregnancies. They are great. You won't have one physician but rather will see a team. Some doctors I liked better than others but all made me feel confident and assured that I was getting great treatment. I transferred there from my regular ob/gyn when I had preterm contractions at 22 weeks and landed at Abbott Northwestern.
http://www.allina.com/ahs/medicalservices.nsf/page/MN_Per...
They have several clinics, I went to the one in Edina by Southdale. A MN Perinatal doctor delivered by c-section my two boys at 34 weeks, 2 days when I developed pre-eclampsyia (sp?).
If you haven't aready, I would highly recommend joining a multiples group (I am with the Minnesota Valley Mothers of Multiples group at http://www.mvmom.org but there are others.) They have a great online forum for questions/answers and support groups for moms on bedrest, kids in NICU, etc. They even have a preemie closet where you can "borrow" clothes if the kids come early. Also a big sale twice a year.
My thoughts are with you. It's a scary but exciting time. Good luck and best wishes!