Any person or persons, other than a regularly licensed physician or osteopath, who shall attend a woman in childbirth for hire, or who shall make a practice of attending women in childbirth gratuitously or for hire, shall be regarded as a midwife within the meaning of this act: Provided, That nothing in this section shall be construed to prevent anyone heretofore licensed under the provisions of any law of this Commonwealth and lawfully possessing a license from practicing midwifery, nor to prohibit a student of medicine or osteopathy, matriculated at, and in attendance at, a legally incorporated medical school or osteopathic college, licensed and approved by the State Board of Medical Education and Licensure or State Board of Osteopathic Examiners, from practicing obstetrics, under the supervision of the faculty of the medical school or osteopathic college in which he or she is a duly registered student.