1. Sue Ann Smith, MD Neonatologist Doernbecher Neonatal Care Center
SGA/IUGR
Sue Ann Smith, MD
Neonatologist
Doernbecher Neonatal Care Center

2. Intrauterine Growth Restriction (IUGR)
No universal definition
Any baby who does not achieve intrauterine growth potential
Usually defined as < 2 SD below the mean for weight.

3. Small for Gestational Age (SGA)
Usually defined as <2SD or <10th % for growth parameters
Babies <3% are at greatest risk of morbidity and mortality.
Babies who are constitutionally small are at less risk of complications than those who are SGA from pathologic process.

4. Etiology of SGA
Maternal Factors
Placental Factors
Fetal Factors

5. Maternal Factors Genetic size Demographics
Age (extremes of reproductive age)
Race
Socioeconomic status
Underweight before pregnancy or malnutrition
Chronic disease
Exposure to teratogens (EtOH, drugs, radiation, etc.)

6. Maternal Factors (cont.)
Factors that interfere with placental flow and function
Postmaturity
Multiple gestation
Uterine anomalies
Thrombotic disease
High altitude environment
Smoking
Cocaine
Heart disease
Renal disease
Hypertension
Pulmonary disease
Hemoglobinopathies
Collagen-vascular disease
Diabetes

7. Placental Factors Malformations – vascular Chorioangioma Infarction
Abruption
Previa
Abnormal trophoblast invasion

8. Fetal Factors
Constitutional – genetically small, but genetically normal
Chromosomal abnormality – only about 5% of SGA babies
Malformations – CNS, skeletal, gastroschisis
Congenital infections – CMV, rubella

9. Characteristics of IUGR
Symmetric
Early onset
Constitutional or “normal” small
Decreased growth potential
Normal ponderal index
Lower risk for transitional problems
Brain symmetrical to body
Examples
Genetic causes, chromosomal
TORCH infections
Anomalad Syndromes

10. Characteristics of IUGR
Asymmetric
Late onset
Environmental
Growth arrest
Higher risk for transitional problems
Brain sparing
Examples
Chronic hypoxia
Preeclampsia (PIH, PET)
Chronic hypertension
Malnutrition

11. Neonatal Complications of IUGR
Mortality rate 5-20x that of AGA
Perinatal asphyxia
Abnormal temperature regulation
Hypoglycemia
Hyperviscosity-polycythemia syndrome
Altered immunity
Thrombocytopenia

12. Neonatal Complications of IUGR(cont)
Pulmonary hemorrhage
PPHN
Hypocalcemia

13. Evaluation of SGA Newborn
Careful physical examination
Measure & plot head circumference & length
CBC with differential and platelet count
Monitor glucose carefully
Further evaluation?
Urine for CMV
TORCH titers
Liver function tests
Head Ultrasound

14. “Long term” Morbidity of IUGR
Factors associated with abnormal outcome ?
Microcephaly
Hypoxic ischemic encephalopathy
Symptomatic hypoglycemia
Symptomatic hyperviscosity

15. Growth Consequences of IUGR
Height at 4 years
Weight at 4 years 50 40 20 30 10
>90
50-90
10-50
<10 50 40 20 30 10
>90
50-90
10-50
<10
Percent
Percent
Percent
Percent
Term AGA
Term SGA
Preterm SGA

16. Growth Consequences of IUGR
Head Circumference at 4 years 50 40 20 30 10
>90
50-90
10-50
<10
Percent
Term AGA
Term SGA
Preterm SGA

17. Fetal Origins of Adult Diseases ?
Coronary artery disease correlates inversely with birth weight
Rate of non-insulin dependent diabetes mellitus is highest in the “thinnest” babies at birth (low ponderal index)
High serum cholesterol are linked to disproportionate size at birth (body smaller than head)
Increased rate of hypertension in infants who were thin, short, &/or proportionately small at birth