2. Definition
Although many use the terms “SGA” and “IUGR” interchangeably, they refer to two
different concepts.
SGA describes a neonate whose birth weight or birth crown–heel length is <10th
percentile for GA or <2 standard deviations (SDs) below the mean for the infant’s GA.
IUGR describes diminished growth velocity in the fetus as documented by at least two
intrauterine growth assessments (e.g., a fetus that is “falling off” its own growth
curve).
After birth, IUGR babies appear malnourished, with poor subcutaneous fat, whereas SGA
babies will look like small but normal babies. Babies who are constitutionally SGA are
at an overall lower risk compared to those who are IUGR due to some pathologic
process. Numerous “normal birth curves” have been published from different
populations. The etiology and management of SGA and IUGR fetuses overlap
considerably.
3. IUGR Facts
IUGR associated with 3-10 % of all pregnancies
Perinatal mortality rate is 5-20 times higher for growth retarded fetuses.
2nd leading contributor to the Perinatal mortality rate
20% of all stillbirths are IUGR
Incidence of intrapartum asphyxia in cases ofIUGR has been reported to be 50%.
Early and proper identification and management lowers this perinatal mortality and morbidity
4. Normal Fetal Growth
Normal fetal growth is characterized by cellular hyperplasia followed by hyperplasia and hypertrophy
and lastly by hypertrophy alone.
Fetal Growth From 8 to 40 Weeks
6. Symmetrical IUGR
Head circumference, length, and weight are all proportionally reduced for grstational age
(below 10 percentile).
It is due to either decreased growth potential of the fetus or extrinsic conditions that are
active in
pregnancy.
Asymmetrical IUGR
Fetal weight is reduced out of proportion to length and headcircumference.
The usual causes are uteroplacental insufficiency, maternal malnutrition, or extrinsic
conditions
appearing late in pregnancy.
7.
8.
9. Diagnosis of IUGR
Identifying mothers at risk
poor maternal nutrition
Poor BMI at conception
Pre-eclampsia Renal disorders
Diseases causes vascular insufficiency
Infections (TORCH)
Poor maternal wt. Gain during pregnancy
10. Diagnosis
Clinical
Palpation of uterus
Serial measurement is important
Fundal height
Liqour volume
Fetal mass
Maternal weight gain-
stationary or falling during second half of pregnancy
SFH(symphysis fundal hieght)
Closely correlates with gestational age after 24weeks
Lag of 4 cm or more- IUGR
Fairly sensitive (30-80%)
Abdominal girth- stationary or falling
11. Biophysical
First examination (16-20 weeks) should confirm
gestational age, anomalies
USG-
2-3 weekly
Diagnosis of IUGR, type
Head circumference/ Abdominal circumference ratios
>1- before 32 weeks Elevated- asymmetrical IUGR
=1-32-34 weeks Normal-asymmetrical IUGR
<1- after 34 weeks 85% IUGR fetuses are detected
AC-Single most sensitive parameter
12. Serial measurements of AC and estimation of fetal weight are more diagnostic
Femur length
Not affected in asymmetric IUGR
FL/AC =22 from 21 weeks to term
FL/AC> 23.5-IUGR
Amniotic fluid volume
Vertical pocket of amniotic fluid <1 cm suggests IUGR
Four quadrant technique-measuring vertical diameter of largest pockets of fluid found in
each of 4 quadrants of uterus. The sum of results is AFI
AFI 5 to 25 cm-normal
AFI< 5 cm- oligohydramnios
Anatomical survey: To exclude fetal abnormalities
Bi-parietal diameter
13. Ultrasound doppler parameters
Doppler velocimetry
Elevated uterine artery S/D ratio (>2.6)
presence of diastolic notch
Diastolic notch suggests incomplete invasion of placental trophoblasts to uterine
spiral arteries
Also predicts possible development of pre-eclampsia Normally, diastolic flow
increases as pregnancy progresses.
Reduced/absent/reversed diastolic flow in umbilical artery indicates fetal
jeopardy and poor perinatal outcome
14. Middle cerebral artery
Increased diastolic velocity(brain sparing effect) in compromised fetus
Cerebro-Placental Doppler ratio [RI (mca)/ RI (umb. A.)] is decreased
The normal ratio is > 1.
PI
Degree of fetal wasting judged
(birth weight/Crown-heel length 3)
<10 th percentile –IUGR
Reduction of fetal facial fat stores- IUGR
16. Complications
Fetal
Antenatal- chronic fetal distress, fetal death, diminished amniotic fluid volume
increases the likelihood of cord compression
Intranatal –hypoxia, acidosis
After birth- immediate
-late
17. Immediate
Asphyxia, bronchopulmonary dysplasia and RDS
Hypoglycemia due to shortage of glycogen reserve in liver because of chronic hypoxia
Meconium aspiration syndrome
Microcoagulation leading to DIC
Hypothermia
Pulmonary haemorrhage
Polycythaemia, anaemia, thrombocytopenia Hyperviscosity thrombosis
Necrotising enterocolitis due to reduced intestinal blood flow
IVH
19. Late
Symmetrical growth retarded baby is likely to grow slowly after birth
Asymmetrical- catch up growth in early infancy
1. retarded neurologic and intellectual development in infancy
Worst prognosis- congenital infection, congenital abnormalities,
chromosomal defects
2. Increased risk- metabolic syndrome in adult life: obesity, hypertension,
diabetes, coronary heart disease
20. 3. altered orexigenic mechanism that causes increased appetite and reduced satiety
4. Reduced no of nephrons- renal vascular hypertension
21. Management of Small for Gestational Age/Intrauterine Growth
Restriction
Pregnancy
a. Attempt to determine the cause of SGA/IUGR by searching for relevant factors by
history, laboratory, and ultrasonic examination. Treat any underlying cause when
possible.
Chronic fetal hypoxemia is encountered in about 30% of SGA/IUGR fetuses.
b. Monitor fetal well-being, including nonstress test, a biophysical profile, fetal
movement counts, amniotic fluid volume evaluation, and serial ultrasonic
examinations.
Doppler evaluation of placental flow may be used to evaluate uteroplacental
insufficiency.
c. Consider the effects of prematurity if early delivery is contemplated.
22. Delivery.
Early delivery is necessary if the risk of intrauterine fetal demise still is considered greater
than the risks of preterm birth.
A. Generally, indications for delivery are an arrest of fetal growth and/or fetal distress,
especially closer to term.
b. Acceleration of pulmonary maturity with glucocorticoids administered to the mother should
be considered at 24 to 34 weeks pregnancy.
C. If there is poor placental blood flow, the fetus may not tolerate labor and may require a
cesarean delivery.
D. Infants with extreme SGA/IUGR are at a risk for perinatal complications and often require
specialized care in the first few days of life. Therefore, if possible, delivery should occur at
a center with a NICU or special care nursery. The delivery team should be prepared to
manage perinatal depression, meconium aspiration, hypoxia, hypoglycemia, and heat loss.
23. Management of new born
Delivery
Resuscitation
Prevention of heat loss
Hypoglycemia
Hematologic disorders
Congenital infections
Genetic anomalies
24. Potential complications related to SGA/IUGR
i. Congenital anomalies
ii. Perinatal depression
iii. Meconium aspiration, persistent pulmonary hypertension
iv. Hypoglycemia from depletion of glycogen stores
v. Hypothermia from depletion of subcutaneous fat
vi. Polycythemia
vii. Neutropenia
viii. Thrombocytopenia
ix. Hypocalcemia
