Population-based reference for birth weight for gestational age in northern China.
BACKGROUND
Localized birth weight references for gestational age serve as an essential tool in accurate evaluation of atypical birth outcomes (e.g. small for gestational age) in clinical diagnosis and region-specific epidemiological studies. Such standards are currently not available in Mainland China.


OBJECTIVE
To construct up-to-date, sex- and parity-specific birth weight references based on 231,937 births in Taiyuan, China during years 2005-2011.


METHODS
Population-based, cross-sectional.


METHODS
Hospital-registered, healthy infants with births dated between 11/01/2005 and 12/31/2011 within Taiyuan area.


METHODS
Birth weight in grams, and gestational age in complete weeks were calculated using a combination of last-menstrual-date-based estimation and ultrasound examination.


RESULTS
Separate birth weight references are constructed for male and female infants born from primiparous and multiparous mothers. Male infants are found to weigh more than female infants in later gestational ages (appr. weeks 33-42), and infants born to multiparous mother are found to weigh more than infants born to primiparous mothers in later gestational ages (appr. weeks 36-42).


CONCLUSIONS
The Taiyuan birth weight reference curves display similar trends of growth as reference curves from other countries worldwide (Netherlands, Scotland, Australia, Canada, Hong Kong, Korea and Kuwait). However, growth of birth weight for Taiyuan infants tends to be slower compared to European and North American infants regardless of gender, but similar to infants from other Asian countries.
Department of Biostatistics, Harvard School of Public Health, Boston, MA, United States; State Key Laboratory of Environmental Criteria and Risk Assessment & Environmental Standards Institute, Chinese Research Academy of Environmental Sciences, Beijing, China. Electronic address: zhel90@gmail.com.
Zhe
Z
Liu
State Key Laboratory of Environmental Criteria and Risk Assessment & Environmental Standards Institute, Chinese Research Academy of Environmental Sciences, Beijing, China.
Jinliang
J
Zhang
Center for Public Health Surveillance, Taiyuan Municipal Center for Disease Control and Prevention, Taiyuan, Shanxi, China.
Baoxin
B
Zhao
Center for Public Health Surveillance, Taiyuan Municipal Center for Disease Control and Prevention, Taiyuan, Shanxi, China.
Xiaoping
X
Xue
Center for Public Health Surveillance, Taiyuan Municipal Center for Disease Control and Prevention, Taiyuan, Shanxi, China.
Lizhen
L
Xu
School of Public Health, Shanxi Medical University, Taiyuan, Shanxi, China.
Fenfen
F
Wang
State Key Laboratory of Environmental Criteria and Risk Assessment & Environmental Standards Institute, Chinese Research Academy of Environmental Sciences, Beijing, China; Center for Public Health Surveillance, Taiyuan Municipal Center for Disease Control and Prevention, Taiyuan, Shanxi, China.
Yanping
Y
Zhang
D001724:Birth Weight; D002681:China; D003430:Cross-Sectional Studies; D005260:Female; D005865:Gestational Age; D057238:Growth Charts; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D012737:Sex Factors
Asian population; Birth weight; Chinese population; Meta-analysis; Reference curve