State maternal mortality study com Assessment of the relative importance of factors effecting reductions in maternal deaths is essential for planning and implementing needed health programs.' Since reduction or elimination of avoidable factors in maternal deaths constitutes a primary goal of maternal mortality study committees,2 maternal mortality ratios (maternal deaths/100,000 live births) provide useful indices for evaluating the impact of these committees on the quality of health care.3 Maternal mortality ratios in the United States have declined exponentially since 1930,1 and state maternal mortality study committees have been widely credited with playing a prominent role in this decline.1-7 Most attempts to measure the outcome of maternal mortality reviews, however, have lacked comparison groups. Having observed decreases in maternal mortality ratios in states with review committees, many authors1-7 have inferred a causal relationship. Whether the association between these committees and declining mortality ratios is causal or merely temporal, however, has not been established. To assess the impact of state maternal mortality study committees on maternal death rates, we compared the declines in the maternal mortality ratios by decades from 1938-40 to 1968-70 for states with committees to those without.