title: Approximately one-third of medically indicated late preterm births are complicated by fetal growth restriction.
abstract: OBJECTIVE
  The purpose of this study was to report the frequency of fetal growth restriction (FGR) based on indication for late preterm birth (LPTB).
  
  
  METHODS
  Singleton live born pregnancies that were delivered from 34-36 weeks 6 days of gestation over a 1-year period at a tertiary care medical center were studied. Indications for delivery were categorized as spontaneous (spontaneous preterm birth or premature rupture of membranes), medically indicated, or elective. A customized birthweight percentile was calculated for each pregnancy; the rate of FGR was compared based on indication for LPTB.
  
  
  RESULTS
  There were 482 LPTBs that met all criteria. Customized birthweight percentiles (median; interquartile range) were different among groups (spontaneous, 45.5%; 20.8-73.5%; medically indicated, 26.9%; 4.1-63.6%; elective, 45.9%; 22.2-78.3%; P = .001). The rate of FGR was also different among groups (spontaneous, 13%; medically indicated, 32%; elective, 21%; P = .001).
  
  
  CONCLUSIONS
  With the use of customized birthweight standards, we found that FGR complicated approximately one-third of all cases of medically indicated LPTB.
authors.affiliation: Division of Maternal-Fetal Medicine, Department of Obstetrics, Gynecology and Reproductive Sciences, The University of Texas Medical School at Houston, 6431 Fannin Street, Houston, TX 77030, USA. carlos.carreno@uth.tmc.edu
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Carreno
authors.forename: Maged M
authors.initials: MM
authors.lastname: Costantine
authors.forename: Marium G
authors.initials: MG
authors.lastname: Holland
authors.forename: Susan M
authors.initials: SM
authors.lastname: Ramin
authors.forename: George R
authors.initials: GR
authors.lastname: Saade
authors.forename: Sean C
authors.initials: SC
authors.lastname: Blackwell
mesh_terms: D000328:Adult; D015897:Comorbidity; D005260:Female; D005317:Fetal Growth Retardation / Q000453:epidemiology*; D006801:Humans; D011247:Pregnancy; D047928:Premature Birth / Q000453:epidemiology*