Maternal death rates represent the single largest health discrepancy between developed and developing populations, with nearly all - over 99% -- maternal deaths worldwide occurring in developing countries and over half of them in sub-Saharan Africa countries. Eliminating maternal mortality, which is defined as the deaths related to pregnancy, would result in a gain of over a half year (0.6 years) in life expectancy worldwide, according to a new study by researchers at Johns Hopkins Bloomberg School of Public Health. The study is published February 13 in PLOS ONE.