Last update: Nov 2007

The vast majority of underweight births occur in the developing world

More than 19 million infants are born at a low birthweight -- 16 per cent of all births in the developing world. The level of low birthweight in developing countries is more than double that of industrialized countries. In fact, more than 96 per cent of low-birthweight babies are born in the developing world.

There is a significant variation in low-birthweight incidence across the developing world, ranging from six per cent to 29 per cent. South Asia has the highest incidence with nearly one-third (29 per cent) of all infants born with low birthweight. The lowest incidence, at six per cent, is in East Asia and the Pacific and Central and Eastern Europe/Commonwealth of Independent States (CEE/CIS).

India alone is home to more than 40 per cent of all low-birthweight infants in the developing world. Nearly one in every seven infants in Sub-Saharan Africa (14 per cent) and the Middle East and North Africa (15 per cent) are also born with low birthweight.

South Asia and Sub-Saharan Africa combined account for more than three-quarters (78 per cent) of low-birthweight infants in the developing world. South Asia alone accounts for more than half (57 per cent), and is also the region where most infants are not weighed at birth.

Trend analysis is difficult

There is a lack of comparable estimates over time, both within and between countries. Limited trend data, however, are available from Developmental and Health Surveys (DHS) and Multiple Indicator Cluster Surveys (MICS) covering 44 developing countries, or about 60 per cent of the developing world's population excluding China.

A population-weighted average for available survey points around 1990 and 2006 shows that the incidence of low birthweight remained roughly constant during this period. The lack of change appears to apply in both Sub-Saharan Africa and Asia. Available trend data are insufficient for other regions.