1. Global causes of maternal death: a WHO systematic analysis;L Say;Lancet Glob Heal,2014
2. World Health Organization. Maternal Mortality [Internet]. Factsheet. 2016. Available from: http://www.who.int/mediacentre/factsheets/fs348/en/
3. Global, regional, and national levels and trends in maternal mortality between 1990 and 2015, with scenario-based projections to 2030: a systematic analysis by the UN Maternal Mortality Estimation Inter-Agency Group;L Alkema;Lancet,2016
4. National Population Comission (NPC) Nigeria and ICF International. Nigeria Demographic and Health Survey 2013. Abuja, Nigeria and Rockville, Maryland; 2014.
5. World Bank Group. Maternal Mortality Risk [Internet]. Indicator. Available from: http://data.worldbank.org/indicator/SH.MMR.RISK