Among the social origins of the Social Support and Pregnancy Outcome study, as described in Chapter 1, was the idea that social support is good for health. This chapter attempts to draw together ideas, insights, and problems from disparate areas of sociology, psychology, psychiatry, history, epidemiology, and medicine to address the question: why, in the first place, should anyone suppose that social support can be helpful to childbearing women and their families? The discussions cover the health outcomes influenced by social support; the link between social support and reproduction; how social support works; and the research challenge posed by the certain hostility of modern medicine towards the role of social factors in influencing patterns of health and illness.