title: Customized versus Population-Based Birth Weight References for Predicting Fetal and Neonatal Undernutrition.
abstract: OBJECTIVE
  The aim of our study was to construct a model of customized birth weight curves based on a Spanish population and to compare the ability of this customized model to our population-based chart to predict a neonatal ponderal index (PI) <10th percentile.
  
  
  METHODS
  We developed a model that can predict the 10th percentile for a fetus according to gestational age and gender as well as maternal weight, height, and age. We compared the ability of this customized model to that of our own population-based model to predict a neonatal PI <10th percentile. Data from a large database were used (32,854 live newborns, from 1993 through 2012). Only singleton pregnancies with a gestational age at delivery of 32-42 weeks were included.
  
  
  RESULTS
  In the entire pregnant population, the customized method was superior to the population-based method for detecting newborns with a PI <10th percentile (sensitivity: 55 vs. 40.96%; specificity: 99.6 vs. 91.23%; positive predictive value: 11.49 vs. 9.55%, and negative predictive value: 98.84 vs. 98.55%, respectively). In pregnant women with a BMI >90th percentile, the sensitivity was 75%, compared to 50% in the population-based method. In pregnant women with a height >90th percentile, the sensitivity was almost as high as in the population-based method (61.53 vs. 33.33%).
  
  
  CONCLUSIONS
  The customized birth weight curve is superior to the population-based method for the detection of newborns with a PI <10th percentile. This is especially the case in women in the higher scales of height and weight as well as in preterm babies.
authors.affiliation: Departamento de Obstetricia y Ginecologx00ED;a, Hospital Universitario de Puerto Real, Cx00E1;diz, Spain.
authors.forename: Juan Jesús
authors.initials: JJ
authors.lastname: Fernández-Alba
authors.forename: Carmen
authors.initials: C
authors.lastname: González-Macías
authors.forename: Raquel
authors.initials: R
authors.lastname: León Del Pino
authors.forename: Fabiana
authors.initials: F
authors.lastname: Prado Fernandes
authors.forename: Carolina
authors.initials: C
authors.lastname: Lagares Franco
authors.forename: Luis Javier
authors.initials: LJ
authors.lastname: Moreno-Corral
authors.forename: Rafael
authors.initials: R
authors.lastname: Torrejón Cardoso
mesh_terms: D000328:Adult; D001724:Birth Weight; D001827:Body Height; D001835:Body Weight; D005260:Female; D047109:Fetal Development; D048070:Fetal Nutrition Disorders / Q000175:diagnosis*; D005865:Gestational Age; D006801:Humans; D007231:Infant, Newborn; D007236:Infant, Small for Gestational Age; D008297:Male; D008962:Models, Theoretical; D057285:Precision Medicine / Q000379:methods; D011237:Predictive Value of Tests; D012016:Reference Values; D012680:Sensitivity and Specificity; D012737:Sex Factors; D013030:Spain / Q000453:epidemiology