Persons, who are interested in becoming an obstetrician/gynecologist, must complete four years of undergraduate school at an accredited college or university, four years of medical school specializing in obstetrics and gynecology, and a three to eight year internship and residency in a hospital setting.f you are thinking about becoming an obstetrician/gynecologist, you must strongly desire serving patients, be a self-motivator, be deeply concerned about women's health, and be able to withstand the long hours and pressures of medical school, education and training, and medical practice.