Maternal-fetal medicine specialists, also known as MFM specialists, perinatologists, and high-risk pregnancy physicians, are highly trained obstetrician/gynecologists with advanced expertise in obstetric, medical, and surgical complications of pregnancy and their effects on the mother and fetus. In the United States, maternal-fetal medicine physicians are fully trained and qualified obstetrician/gynecologists who, upon fulfilling the requirements of a three-year fellowship and satisfactorily completing written and oral examinations, are certified as subspecialists by the American Board of Obstetrics and Gynecology (ABOG). In addition, the American Osteopathic Board of Obstetrics and Gynecology (AOBOG) confers subspecialty certification in Maternal-Fetal Medicine to physicians who have primary certification in Obstetrics and Gynecology, have successfully completed a three year fellowship and research requirements, and have passed the subspecialty clinical examination. Outside the United States, subspecialty certification in Maternal-Fetal Medicine may be offered on successful completion of training and examination requirements by national bodies (e.g., The Royal College of Physicians and Surgeons of Canada).