Estimates for 2015 suggest that 5.9 million children worldwide died before reaching the age of five, including 2.7 million newborns. Globally, 4.02 million fewer child deaths occurred in 2015 than in 2000, mainly thanks to reductions in deaths from pneumonia, diarrhoea, death during birth, malaria and measles.

However, progress on reducing newborn deaths (in the first 28 days) has been slower meaning that as a whole the world failed to reach the Millennium Development Goal (MDG) target of reducing child deaths by two-thirds between 1990 and 2015.

The study, published in The Lancet, provides the most up-to-date figures for deaths of children under five years old and includes data for all 194 countries that are World Health Organisation states.

Although the number of newborn deaths was reduced from 3.9 million in 2000 to 2.7 million in 2015, progress has been slower than the improvements in survival for one month to five year olds.

If newborn deaths had reduced at the same rate as that of children aged between one month and five years old the MDG target to reduce child deaths by two-thirds between 1990 to 2015 might have been reached.