A systematic review of individual and ecological determinants of maternal mortality in the world based on the income level of countries

BACKGROUND: This systematic review was conducted to map the literature on all the existing evidence regarding individual and ecological determinants of maternal mortality in the world and to classify them based on the income level of countries. Such a systematic review had not been conducted before. METHODS: We conducted an electronic search for primary and review articles using “Maternal Mortality” and “Determinant” as keywords or MeSH terms in their Title or Abstract, indexed in Scopus, PubMed, and Google with no time or geographical limitation and also hand searching was performed for most relevant journals. STROBE and Glasgow university critical appraisal checklists were used for quality assessment of the included studies. Data of the determinants were extracted and classified into individual or ecological categories based on income level of the countries according to World Bank classification. RESULTS: In this review, 109 original studies and 12 review articles from 33 countries or at global level met the inclusion criteria. Most studies were published after 2013. Most literature studied determinants of low and lower-middle-income countries. The most important individual determinants in low and lower-middle-income countries were location of birth, maternal education, any delays in health services seeking, prenatal care and skilled birth attendance. Household-related determinants in low-income countries included improved water source and sanitation system, region of residence, house condition, wealth of household, and husband education. Additionally, ecological determinants including human resources, access to medical equipment and facilities, total fertility rate, health financing system, country income, poverty rate, governance, education, employment, social protection, gender inequality, and human development index were found to be important contributors in maternal mortality. A few factors were more important in higher-income countries than lower-income countries including parity, IVF births, older mothers, and type of delivery. CONCLUSION: A comprehensive list of factors associated with maternal death was gathered through this systematic review, most of which were related to lower-income countries. It seems that the income level of the countries makes a significant difference in determinants of maternal mortality in the world.