title: New Korean reference for birth weight by gestational age and sex: data from the Korean Statistical Information Service (2008-2012).
abstract: OBJECTIVE
  To construct new Korean reference curves for birth weight by sex and gestational age using contemporary Korean birth weight data and to compare them with the Lubchenco and the 2010 United States (US) intrauterine growth curves.
  
  
  METHODS
  Data of 2,336,727 newborns by the Korean Statistical Information Service (2008-2012) were used. Smoothed percentile curves were created by the Lambda Mu Sigma method using subsample of singleton. The new Korean reference curves were compared with the Lubchenco and the 2010 US intrauterine growth curves.
  
  
  RESULTS
  Reference of the 3rd, 10th, 25th, 50th, 75th, 90th, and 97th percentiles birth weight by gestational age were made using 2,249,804 (male, 1,159,070) singleton newborns with gestational age 23-43 weeks. Separate birth weight curves were constructed for male and female. The Korean reference curves are similar to the 2010 US intrauterine growth curves. However, the cutoff values for small for gestational age (<10th percentile) of the new Korean curves differed from those of the Lubchenco curves for each gestational age. The Lubchenco curves underestimated the percentage of infants who were born small for gestational age.
  
  
  CONCLUSIONS
  The new Korean reference curves for birth weight show a different pattern from the Lubchenco curves, which were made from white neonates more than 60 years ago. Further research on short-term and long-term health outcomes of small for gestational age babies based on the new Korean reference data is needed.
authors.affiliation: Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Jung Sub
authors.initials: JS
authors.lastname: Lim
authors.affiliation: Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Se Won
authors.initials: SW
authors.lastname: Lim
authors.affiliation: Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Ju Hyun
authors.initials: JH
authors.lastname: Ahn
authors.affiliation: Department of Pediatrics, Korea Cancer Center Hospital, Seoul, Korea.
authors.forename: Bong Sub
authors.initials: BS
authors.lastname: Song
authors.affiliation: Department of Pediatrics, Kyung Hee University School of Medicine, Seoul, Korea.
authors.forename: Kye Shik
authors.initials: KS
authors.lastname: Shim
authors.affiliation: Department of Pediatrics, Hallym University College of Medicine, Seoul, Korea.
authors.forename: Il Tae
authors.initials: IT
authors.lastname: Hwang
keywords: Birth weight; Gestational age; Growth charts; Koreans; Small for gestational age infant