This review of the literature on social support and its relationship to maternal health indicates that emotional, tangible, and informational support are positively related to mothers' mental and physical health around the time of childbirth. The importance of various types of support changes with the changing needs of women as they move from pregnancy to labor and delivery, and then to the postpartum period. During pregnancy, emotional and tangible support provided by the spouse and others is related to the expectant mother's mental well-being. In addition, informational support in the form of prenatal classes is related to decreased maternal physical complications during labor and delivery, and to improved physical and mental health postpartum. Mothers who have the support of a companion during labor and delivery experience fewer childbirth complications and less postpartum depression. Mothers' postpartum mental health is related to both the emotional support and practical help (eg, housework and child care activities) provided by the husband and others. Health care providers are in a unique position to educate prospective parents about the importance of social support around the time of childbirth and may play a critical role in mobilizing support systems for new mothers.