Cesarean section rates and maternal and neonatal mortality in low-, medium-, and high-income countries: an ecological study.

Background: Cesarean section rates show a wide variation among countries in the world, ranging from 0.4 to 40 percent, and a continuous rise in the trend has been observed in the past 30 years. Our aim was to explore the association of cesarean section rates of different countries with their maternal and neonatal mortality and to test the hypothesis that in low-income countries, increasing cesarean section rates were associated with reductions in both outcomes, whereas in high-income countries, such association did not exist.
Methods: We performed a cross-sectional multigroup ecological study using data from 119 countries from 1991 to 2003. These countries were classified into 3 categories: low-income (59 countries), medium-income (31 countries), and high-income (29 countries) countries according to an international classification. We assessed the ecological association between national cesarean section rates and maternal and neonatal mortality by fitting multiple linear regression models.
Results: Median cesarean section rates were lower in low-income than in medium- and high-income countries. Seventy-six percent of the low-income countries, 16 percent of the medium-income countries, and 3 percent of high-income countries showed cesarean section rates between 0 and 10 percent. Three percent of low-income countries, 36 percent of medium-income countries, and 31 percent of high-income countries showed cesarean section rates above 20 percent. In low-income countries, a negative and statistically significant linear correlation was observed between cesarean section rates and neonatal mortality and between cesarean section rates and maternal mortality. No association was observed in medium- and high-income countries for either neonatal mortality or maternal mortality.
Conclusions: No association between cesarean section rates and maternal or neonatal mortality was shown in medium- and high-income countries. Thus, it becomes relevant for future good-quality research to assess the effect of the high figures of cesarean section rates on maternal and neonatal morbidity. For low-income countries, and on confirmation by further research, making cesarean section available for high-risk pregnancies could contribute to improve maternal and neonatal outcomes, whereas a system of care with cesarean section rates below 10 percent would be unlikely to cover their needs.