title: [Incidence of low birth weight of neonates and the influencing factors in China].
abstract: OBJECTIVE
  To analyze the incidence of low birth weight and identify the influencing factors in China in 2006.
  
  
  METHODS
  The national survey was performed by stratified random cluster sampling method in 43 cities and counties in 14 provinces. The subjects were all live neonates during May to October in 2006. Their body weight was measured according to the standardization conducted by the national research team, while the information of all infants was investigated by questionnaires. Non-conditional logistic regression was used to analyze the influencing factors.
  
  
  RESULTS
  Among 18 554 infants investigated, the incidence of low birth weight was 4.6% in 2006 in China, being 3.2%, 4.4%, and 6.3% in eastern middle and western areas respectively. The incidence of low birth weight were 3.9% in urban and 4.8% in rural. The results of logistic regression analysis suggested that maternal education (OR = 1.48; 95% CI: 1.181 approximately 1.861), body mass index (BMI) before pregnancy (OR = 1.52; 95% CI: 1.229 - 1.876), body weight gain in gestation period (OR = 1.57; 95% CI: 1.246 - 1.965), gestational weeks (OR = 20.16; 95% CI: 15.456 - 26.297), multiple birth (OR = 12.11; 95% CI: 9.229 - 15.893), gestation syndrome, and nutrition instruction (OR = 0.66; 95% CI: 0.550 - 0.798) were associated with low birth weight significantly.
  
  
  CONCLUSIONS
  The main factors resulting in low birth weight in neonates are maternal education, BMI before pregnancy, body weight gain in gestation period, pregnancy age, multiple birth, gestation syndrome, and nutrition instruction.
authors.affiliation: National Institute for Nutrition and Food Safety, Chinese Center for Disease Control and Prevention, Beijing 100050, China.
authors.forename: Dong-Mei
authors.initials: DM
authors.lastname: Yu
authors.forename: Li-Yun
authors.initials: LY
authors.lastname: Zhao
authors.forename: Ai-Dong
authors.initials: AD
authors.lastname: Liu
authors.forename: Wen-Tao
authors.initials: WT
authors.lastname: Yu
authors.forename: Feng-Mei
authors.initials: FM
authors.lastname: Jia
authors.forename: Ji-Guo
authors.initials: JG
authors.lastname: Zhang
authors.forename: Feng-Ying
authors.initials: FY
authors.lastname: Zhai
mesh_terms: D015992:Body Mass Index; D002681:China / Q000453:epidemiology; D005260:Female; D006801:Humans; D007226:Infant Mortality; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D009035:Mothers; D011247:Pregnancy; D012307:Risk Factors; D011795:Surveys and Questionnaires