title: Optimizing the definition of intrauterine growth restriction: the multicenter prospective PORTO Study.
abstract: OBJECTIVE
  The objective of the Prospective Observational Trial to Optimize Pediatric Health in Intrauterine Growth Restriction (IUGR) (PORTO Study), a national prospective observational multicenter study, was to evaluate which sonographic findings were associated with perinatal morbidity and mortality in pregnancies affected by growth restriction, originally defined as estimated fetal weight (EFW) <10th centile.
  
  
  METHODS
  Over 1100 consecutive ultrasound-dated singleton pregnancies with EFW <10th centile were recruited from January 2010 through June 2012. A range of IUGR definitions were used, including EFW or abdominal circumference <10th, <5th, or <3rd centiles, with or without oligohydramnios and with or without abnormal umbilical arterial Doppler (pulsatility index >95th centile, absent or reversed end-diastolic flow). Adverse perinatal outcome, defined as a composite outcome of intraventricular hemorrhage, periventricular leukomalacia, hypoxic ischemic encephalopathy, necrotizing enterocolitis, bronchopulmonary dysplasia, sepsis, and death was documented for all cases.
  
  
  RESULTS
  Of 1116 fetuses, 312 (28%) were admitted to neonatal intensive care unit and 58 (5.2%) were affected by adverse perinatal outcome including 8 mortalities (0.7%). The presence of abnormal umbilical Doppler was significantly associated with adverse outcome, irrespective of EFW or abdominal circumference measurement. The only sonographic weight-related definition consistently associated with adverse outcome was EFW <3rd centile (P = .0131); all mortalities had EFW <3rd centile. Presence of oligohydramnios was clinically important when combined with EFW <3rd centile (P = .0066).
  
  
  CONCLUSIONS
  Abnormal umbilical artery Doppler and EFW <3rd centile were strongly and most consistently associated with adverse perinatal outcome. Our data call into question the current definitions of IUGR used. Future studies may address whether using stricter IUGR cutoffs comparing various definitions and management strategies has implications on resource allocation and pregnancy outcome.
authors.affiliation: Department of Obstetrics and Gynecology, Royal College of Surgeons in Ireland, Dublin, Ireland. juliaunterscheider@rcsi.ie
authors.forename: Julia
authors.initials: J
authors.lastname: Unterscheider
authors.forename: Sean
authors.initials: S
authors.lastname: Daly
authors.forename: Michael Patrick
authors.initials: MP
authors.lastname: Geary
authors.forename: Mairead Mary
authors.initials: MM
authors.lastname: Kennelly
authors.forename: Fionnuala Mary
authors.initials: FM
authors.lastname: McAuliffe
authors.forename: Keelin
authors.initials: K
authors.lastname: O'Donoghue
authors.forename: Alyson
authors.initials: A
authors.lastname: Hunter
authors.forename: John Joseph
authors.initials: JJ
authors.lastname: Morrison
authors.forename: Gerard
authors.initials: G
authors.lastname: Burke
authors.forename: Patrick
authors.initials: P
authors.lastname: Dicker
authors.forename: Elizabeth Catherine
authors.initials: EC
authors.lastname: Tully
authors.forename: Fergal Desmond
authors.initials: FD
authors.lastname: Malone
mesh_terms: D000328:Adult; D005260:Female; D005317:Fetal Growth Retardation / Q000000981:diagnostic imaging* / Q000453:epidemiology; D020567:Fetal Weight; D006801:Humans; D007231:Infant, Newborn; D054238:Perinatal Mortality; D011247:Pregnancy; D011256:Pregnancy Outcome; D011446:Prospective Studies; D014463:Ultrasonography