Knowledge gaps in scientific literature on maternal mortality: a systematic review.

Issues related to maternal mortality have generated a lot of empirical and theoretical information. However, despite the amount of work published on the topic, maternal mortality continues to occur at high rates and solutions to the problem are still not clear. Scientific research on maternal mortality is focused mainly on clinical factors. However, this approach may not be the most useful if we are to understand the problem of maternal mortality as a whole and appreciate the importance of economical, political and social macrostructural factors. In this paper, we report the number of scientific studies published between 2000 and 2004 about the main causes of maternal death, as identified by WHO, and compare the proportion of papers on each cause with the corresponding burden of each cause. Secondly, we systematically review the characteristics and quality of the papers on the macrostructural determinants of maternal mortality. In view of their burden, obstructed labour, unsafe abortion and haemorrhage are proportionally underrepresented in the scientific literature. In our review, most studies analysed were cross-sectional, and were carried out by developed countries without the participation of researchers in the developing countries where maternal mortality was studied. The main macrostructural factors mentioned were socioeconomic variables. Overall, there is a lack of published information about the cultural and political determinants of maternal mortality. We believe that a high-quality scientific approach must be taken in studies of maternal mortality in order to obtain robust comparative data and that study design should be improved to allow causality between macrostructural determinants and maternal mortality to be shown.