Tricia Shimer, M.D., P.A. Board Certified OB/GYN in Dallas, TX. Dr. Tricia Shimer, born in Holland to a military family, spent most of her life in Texas. From a very young age she has had a natural curiosity and interest in the sciences, which led her to Texas A&M University where she graduated in 1993 with a degree in Molecular and Cellular ....