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