Early Onset Growth Restriction


Early Onset Growth Restriction, Early Onset IUGR, Symmetric IUGR, Symmetric Intrauterine Growth Retardation

  • Epidemiology
  1. Early onset Fetal Growth Restriction (<32 weeks gestation) accounts for 20-30% of cases of IUGR
  • Background
  1. IUGR is now divided into early and late onset (before or after 32 weeks gestation)
    1. Replaces prior symmetric vs asymmetric classification, which did not predict outcomes as well
  2. Early onset is more severe and progressive than late onset IUGR
    1. Associated with decreased umbilical artery flow in 70%
    2. Associated with perinatal death in 7%
  • Associated Conditions
  1. Associated with Preeclampsia in 35% of cases
  2. Chromosome or genetic abnormalities in 20% of cases
  • Pathophysiology
  1. Intrauterine Growth Retardation onset <32 weeks
  2. Associated with serious neurologic sequelae
  3. Early onset typically affects both Head and body growth
    1. However asymmetry is less predictive of complications than timing