II. Epidemiology
- Represents 70-80% of cases of Intrauterine Growth Restriction
III. Background
- Late onset Fetal Growth Retardation has onset >32 weeks gestation
- Typically results from utero-placental insufficiency (see causes below)
- Previously described as Asymmetric Intrauterine Growth Retardation
- However, timing of onset (early or late) is more predictive of complication than asymmetry
- Intrauterine Growth Retardation with head sparing
- Severe Asymmetric IUGR may become Symmetric IUGR
- Associated with chronic Fetal Hypoxia
- Less severe than Early Onset IUGR
- Abnormal umbilical artery in <10%
- Rare perinatal death
IV. Associated Conditions
- Preeclampsia in 12% of cases (greater association with Early Onset IUGR)
V. Causes: Utero-Placental Insufficiency
- See Intrauterine Growth Retardation
- Maternal Preeclampsia or Chronic Hypertension
- Gestational Diabetes (Second most common cause IUGR)
- Maternal Collagen Vascular Disease
- Maternal Tobacco Abuse
- Most common preventable cause of IUGR
- Birth weight reduced 200 grams if mother smokes
- Maternal Infection
VI. Management
VII. Complications
- Fewer neurologic complications than Early Onset IUGR
- Perinatal complications
- Polycythemia (hyperviscosity)
- Hypoglycemia