A global review of the key interventions related to reproductive, maternal, newborn and child health. The document is designed to facilitate decision-making in low- and middle-income countries about how to allocate limited resources for maximum impact on the health of women and children. The document reviewed more than 50 000 scientific papers to determine the proven effectiveness of interventions and impact on survival, identifying 56 essential interventions that when implemented in "packages" relevant to local settings, are most likely to save lives.