Diseases such as pneumonia, diarrhoea and malaria alone continue to account for about one third of deaths among children under five, many under-five deaths still occur in children already weakened by undernutrition, and many pregnant women continue to face serious constraints to improve their nutrient intake, especially in low-income countries (United Nations, 2015a, United Nations Childrens Fund, 2013b). These challenges are compounded by the urgency of tackling the problem of neonatal deaths. Likewise, it is important to scrutinize the limitations of the health system that have held back the effectiveness of health policy interventions in helping achieve progress towards achieving the health-related MDGs. Policies to expand access to safe drinking water and basic sanitation (MDG 7, target C) have also been critical for achieving health-related goals and are under review in chapter V. The review of health policy interventions is followed by a discussion focused on the constraints of health systems and examples of measures that have enabled Governments to overcome them. Broader issues of governance and institutions that also affect health policies—and development policies in general—are discussed in chapter VI.