One of the most sensitive indicators of the general socioeconomic level of a nation is the infant mortality rate. For industrialized societies, however, the problem of adapting to economic growth concerns less the level of economic growth than whether that growth is relatively smooth or chaotic. Thus, if there is in fact a continuing inverse relationship between economic growth rates and trends in infant mortality, such a relationship should be most accurately observed in comparisons between short and intermediate fluctuations in trends in infant mortality and in the economy. The results of this analysis indicate that significant changes in the trends in perinatal, neonatal, and postneonatal and maternal mortality occur regularly in the United States as a result of environmental change associated with economic fluctuations. The evidence indicates that economic recessions and upswings have played a significant role in fetal, infant, and maternal mortality in the last 45 yr. In fact, economic instability has probably been responsible for the apparent lack of continuity in the decline in infant mortality rates since 1950.