Neonatal

1. 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.)
 Heart disease
 Renal disease
 Hypertension
 Pulmonary disease
 Hemoglobinopathies
 Collagen-vascular
disease
 Diabetes
 Postmaturity
 Multiple gestation
 Uterine anomalies
 Thrombotic disease
 High altitude
environment
 Smoking
 Cocaine
Factors that interfere with placental flow and function

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
50
40
20
30
10
>90
50-90
10-50
<10
Height at 4 years
50
40
20
30
10
>90
50-90
10-50
<10
Weight at 4 years
Percent Percent
Percent
Percent
Term AGA Term SGA Preterm SGA

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