American Journal of Obstetrics and Gynecology 189 September 2003): 861-873.
"Isoimmunization." In Manual of Obstetrics.
They may specialize in oncology, gerontology, psychiatric care, obstetrics or many of the other specialties of medicine.
The American College of Obstetrics and Gynecology, however, sees values in these products, especially after other methods have failed.
Childbirth class instructors, obstetrics personnel, and Internet searches can provide you with referrals.