Trends in out-of-hospital births for the State of Michigan, 1972-79, were examined by analyzing (a) location of deliveries, (b) characteristics of the mother, (c) use of health services, and (d) characteristics of the newborn. A large increase occurred in the number of births at the mother's home and other nonhospital sites for both the black and the white populations. For white women, the increase was associated with better education and greater use of prenatal care. Physician attendance for deliveries at mother's home declined. Birth weights for home-born infants increased significantly over the period, more so for whites than for blacks; mortality declined in some groups, especially for high-birth-weight babies born at the mother's home. Assuming that the rise in home births in the 1970s was due to an increase in planned and not precipitate home deliveries, the authors concluded that these trends reflect, at least in part, the impact of planned out-of-hospital births. Toward the end of the 1970s, both the conditions under which these births occurred and some of their outcome measures were more characteristic of safety than at the beginning of the period. Disaggregation by race demonstrated, however, that the safety factor was not necessarily present for out-of-hospital births of black infants.