[Trendency analysis of infant mortality rate due to premature birth or low birth weight in China from 1996 to 2013].

Objective: To study the secular trend and characteristics of infant mortality rate due to premature birth or low birth weight (IMRPL) in China from 1996 to 2013.

Methods: Data used in this study was collected from the population-based Child's Health Surveillance Network of China. The Cochran-Armitage Trend test and Poisson regression were used to test the trend of IMRPL and explore the differences of the trend among different regions or areas.

Results: The nationwide IMRPL was 629.9 per 100 000 live births in 1996 and it decreased to 214.6 per 100 000 live births in 2013. The average annual decline rate was 6.14%, while the proportion of infant mortality due to premature birth or low birth weight in all infant deaths was on the rise with the average annual growth rate of 1.52%. And the proportion increased to 22.6% in 2013. IMRPLin rural and urban areas fell 28.1% and 66.6% respectively during 1996 and 2013. But the differences between urban and rural areas was obvious. During the same period, the average IMRPLin the central region was 1.40 times (95%CI:1.31-1.49) of that in the eastern region. And the average IMRPL in the western region was 2.25 times (95%CI:2.12-2.40) of that in the eastern region. The differences among different regions was obvious. Male infant mortality rate due to premature birth or low birth weight was 1.09 times (95%CI:1.05-1.14) of that in female infant from 1996 to 2013.

Conclusion: The risk of IMRPL decreased substantially in China from 1996 to 2013. And the risk of IMRPL decreased more in rural areas than that in urban areas. The differences among different regions and areas were obvious. Premature birth or low birth weight as one of main factors has become a serious threat for health of Chinese children.