In all branches of medicine the master word is _prophylaxis_, or prevention, and its benefits are nowhere more strikingly illustrated than in the practice of obstetrics. In former times every woman who gave birth to a child or passed through a miscarriage was exposed to grave danger of infection or child-bed fever; but at present--thanks to the recognition of the bacterial origin of the disease and of its identity with wound infection--this danger can be practically eliminated by the rigid observance of surgical cleanliness and aseptic technique. Physicians have also learned that the most effective method of coping with other serious complications of pregnancy and labor is by preventing their occurrence, or at least by subjecting them to treatment in their earliest stages; for, if they be allowed to go on to full development, the results are little better than in times past. Furthermore, a careful examination some weeks before the expected date of confinement enables us to recognize the existence of abnormal presentations and of disproportion between the size of the mother's pelvis and that of the child's head. Timely recognition of such conditions makes appropriate treatment possible and practically insures a successful outcome; while tardy recognition is frequently followed by disastrous results. These few examples give some idea of the benefits of prophylaxis in the practice of obstetrics. Prospective mothers should understand not only that there is an advantage in taking such precautions, but that they may be risking their lives, or at least their future well-being, unless they insist upon competent medical attention. It is true, of course, that pregnancy and childbirth are generally normal processes, but they are not always so. Fortunately, most of the abnormalities give timely warning of their occurrence, and in most instances may be relieved by comparatively simple measures; or, if not, they afford indications for treatment which should lead to a happy termination. The recognition of the existence of such conditions, however, is not always easy, and their ideal treatment requires careful training and sometimes the utmost nicety of judgment. Consequently, if prospective mothers wish to be assured of the best care, they should be cautious in the choice of their medical attendant. As the ordinary layman has no means of determining the real qualifications of a physician, the choice should not be made upon the advice of casual acquaintances; but, instead, the family physician should be consulted, who, should he feel unwilling to assume the responsibility of the case, will be able to recommend a thoroughly competent substitute.