Sampling survey on low-birth weight in China in 1998

To study the weight of live births and incidence of low-birth weight (LBW) in China.

A national survey on the weight of live births with gestational ages of 28 weeks or over in 16 cities and 28 counties of 11 provinces in China was carried with stratified sampling during July to October, 1998.

Totally 22 350 live newborns, 11 584 males and 10 766 females, with gestational ages of 28 weeks or more in sampling sites were measured at their birth. Rates of multiple births and preterm birth (< 37 weeks of gestation) were 1.8% and 3.5%, respectively. LBW rates were 4.20% and 6.26% for urban and rural areas, respectively, with a national weighted-average of 5.87%. Full term births (>/= 37 weeks of gestation) accounted for 61.2% and 71.6% of the babies with LBW in national and rural areas, respectively. Their average birth weight was 3 301 g and 3 225 g in urban and rural areas, respectively, with statistically significant difference, and 3 280 g and 3 173 g for boys and girls, respectively, approaching to the values recommended by the World Health Organization (WHO). Live birth weight in the coastal, inland, and remote areas appeared a trend of gradual decrease. Early neonatal mortality of babies with LBW was 50.0 per thousand and 179.4 per thousand in urban and rural areas, respectively, with a national average of 151.5 per thousand, significant higher than those with normal birth weight.

The average birth weight and LBW rate in live births of China were close to those in the developed countries, and there was significant difference in them between varied regions. The majority of LBW in China was attributed to intrauterine growth retardation (IUGR). Early neonatal mortality in babies with LBW was significantly higher than that with normal birth weight. Further intervention measures should be implemented.