title: A national sampling survey on birth weight in 1998 in China: mean value and standard deviation.
abstract: OBJECTIVE
  To understand the distribution of live birth weight in China.
  
  
  METHODS
  A national survey on live birth weight was performed during July-October, 1998 in China, with stratified sampling. Totally, 22 350 live newborns (11 584 males and 10 766 females) with 28 weeks or more of gestation were measured for their birth weight in the sampling sites during 1998.
  
  
  RESULTS
  The ratio of male to female newborns measured was 1.08. The rates of multiple birth and preterm birth (< 37 weeks of gestation) were 1.8% and 3.5%, respectively. Live birth weight was higher in the urban areas (3 301 g) than that in the rural area (3 225 g) (t = 9.4. P < 0.001), the highest in the coastal areas (3 262 g), middle in the inland areas (3 254 g) and the lowest in the remote areas (3 115 g) (F = 177.9, P < 0.001), with a decreasing trend. Live birth weight in the first-class rural areas approximated to that in the urban areas, and that in the second-class, third-class and fourth-class rural areas decreased significantly. The average live birth weight in the fourth-class rural areas was 200 g lower than that in the urban areas.
  
  
  CONCLUSIONS
  Generally, the average live birth weight in China was closed to that in the developed countries. But, a big difference in the average live birth weight between regions with varied economic development and health care condition was observed. An intervention measure should be implemented in the poverty-stricken rural areas to increase their average live birth weight.
authors.affiliation: Department of Epidemiology, Capital Institute of Pediatrics, Beijing 100020, China.
authors.forename: Jie
authors.initials: J
authors.lastname: Mi
authors.forename: Liangming
authors.initials: L
authors.lastname: Lin
authors.forename: Yulin
authors.initials: Y
authors.lastname: Liu
authors.forename: Xinli
authors.initials: X
authors.lastname: Zhang
authors.forename: Lanhua
authors.initials: L
authors.lastname: Cao
mesh_terms: D001724:Birth Weight; D002681:China; D003627:Data Interpretation, Statistical; D005260:Female; D006801:Humans; D008297:Male; D011159:Population Surveillance; D011247:Pregnancy; D018873:Pregnancy Rate