New global estimates published in the Lancet Global Health show that in 2014, approximately 10.6 per cent of all live births globally were preterm, equating to 14.84 million births.
Researchers examined available data on preterm birth for the 194 Member States of the World Health Organization for 1990 to 2014 from databases of national civil registration and vital statistics, where available, in addition to population-representative surveys and research studies.
Almost 85 per cent of preterm births occurred between 32 and 37 weeks gestation, and more than 80 per cent occurred in Asia and sub-Saharan Africa.
Estimated regional preterm birth rates ranged from 8.7 per cent in Europe to 13.4 per cent in North Africa. The countries with the highest number of preterm births were India, China, Nigeria, Bangladesh, and Indonesia, which together accounted for 57.9 million of 139.9 million live births and 6.6 million preterm births globally in 2014.
Data from 38 countries with high-quality data showed that preterm birth rates have increased since 2000 in 26 countries and decreased in 12 countries.
The authors highlighted a number of difficulties in estimating the true burden of preterm births due to data availability, and said the quality and volume of data in this area needs to be improved.