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1. FETAL GROWTH
DISORDERS
Presented by: GAY M. SAGUN, M.D

2. FETAL GROWTH
• Nearly 20% of the almost 4 million infants born in the United States
are at the low and high extremes of fetal growth.
• In 2010, 8.2% of infants weighed <2500gm at birth, whereas 7.6%
percent weighed >4000gm

3. • THREE PHASES:
1. 1ST
Phase
- occurs in the first 16 weeks,
- rapid increase in cell number
2. 2ND
Phase
- extends up to 32 weeks gestation
- includes cellular hypertrophy and hyperplasia
3. 3RD
Phase
- after 32 weeks
- most fetal fat and glycogen are accumulated

4. • Corresponding fetal-growth rates:
 5gm/day at 15 weeks
 15 to 20gm/day at 24 weeks
 30 to 35gm/day at 34 weeks

5. • Factors affecting fetal growth
 Insulin and IGF (IGF-I)
 Adipokines (Leptin)
 Adequate supply of nutrients

6. • Fetal growth based on birthweight vary with ethnicity and geographic
region
• Term infants average 3400g at sea level, 3200g at 5000 feet, and 2900g
at 10,000 feet

7. FETAL GROWTH
RESTRICTION

8. FETAL-GROWTH RESTRICTION
• Designated to low birthweight newborns who are SGA
• In 1967, Battaglia and Lubchenco classified SGA neonates as those
whose weights were below the 10th
percentile for their gestational age
• In 1977, Campbell and Thomas described the use of the
sonographically determined head to abdomen circumference ratio
(HC/AC)
• 2 types of growth restriction:
– Symmetrical
– Asymmetrical

9. SYMMETRICAL GROWTH
RESTRICTION
• Proportionally small
• An early insult could result in a relative decrease in cell number and
size
• Chemical exposure, viral infection or cellular development

10. ASYMMETRICAL GROWTH
RESTRICTION
• Disproportionately lagging abdomen
• Might follow a late pregnancy insult such as placental insufficiency
from hypertension
• Resultant diminished glucose transfer and hepatic storage would effect
cell size and fetal abdominal circumference would be reduced
• Such somatic growth restriction is proposed to result from preferential
shunting of oxygen and nutrients to the brain
• This allows normal brain and head growth, that is brain sparing

11. RISK FACTORS AND ETIOLOGIES
• Gestational weight gain and nutrition
• Social deprivation
• Vascular disease
• Renal disease
• Pregestational diabetes
• Chronic hypoxia
• Anemia
• APA syndrome
• Inherited thrombophilias
• In fertility

12. • Placental and cord abnormalities
• Multiple fetuses
• Drugs with teratogenic and fetal effects
• Maternal and fetal infections
• Congenital malformations
• Chromosomal aneuploidies

14. DIAGNOSIS OIF FETAL-GROWTH
RESTRICTION
1. Uterine fundal height
- safe, inexpensive and reasonably accurate screening method
2. Sonographic measurements of fetal size
- the most common method identifying poor fetal growth is
estimation of weight using fetal biometric measurements
- FL is the easiest and the most reproducible
- BPD and HC are dependent on the plane of section and may be
affected by deformative pressures in the skull
- AC are more variable

15. 3. AFV measurement
- association between fetal growth restriction and
oligohydramnios has been recognized
4. Doppler velocimetry
- detected in peripheral vessels such as the umbilical and middle
cerebral arteries
- considered standard in the evaluation and management of the
growth restricted fetus

16. • FIGURE 44-8 Umbilical arterial
Doppler velocimetry studies,
ranging from normal to
markedly abnormal. A. Normal
velocimetry pattern with a
systolic to diastolic (S/D) ratio
of < 3. B. The diastolic velocity
approaching zero reflects
increased placental vascular
resistance. C. During diastole,
arterial flow is reversed
(negative S/D ratio), which is an
ominous sign that may precede
fetal demise.

17. PREVENTION
• Begins before conception, with optimization of maternal medical
conditions, medications and nutrition
• Ant-malarial prophylaxis
• Correction of nutritional deficiencies
• Accurate dating
• According to ACOG, if growth is normal during a pregnancy following
a prior pregnancy complicated by fetal growth restriction, Doppler
velocimetry and fetal surveillance are not indicated
• Prophylaxis with low dose aspirin beginning early in gestation is not
recommended because of its poor efficacy to reduce growth restriction

18. MANAGEMENT
• Patient counseling and prenatal diagnostic testing are indicated
• Antepartum fetal surveillance should include periodic Doppler
velocimetry of the umbilical arteries in addition to more frequent fetal
testing
• Pregnancies complicated by fetal-growth restriction and at risk for
birth before 34 weeks receive antenatal corticosteroids for pulmonary
maturation

20. • Management of the near term fetus
– delivery of a suspected growth restricted fetus with normal
umbilical artery Doppler velocimetry, normal amnionic fluid
volume, and reassuring fetal heart rate testing can likely be deferred
until 38 weeks’ gestation
– recommend delivery at 34 weeks or beyond if there is clinically
significant oligohydramnios
– With a reassuring fetal heart rate pattern, vaginal delivery is planned

21. • Management of the fetus remote from term
– If growth restriction is identified in an anatomically normal fetus
before 34 weeks, and amnionic fluid volume and fetal surveillance
findings are normal, then observation is recommended
– As long as there is interval fetal growth and fetal surveillance test
results are normal, pregnancy is allowed to continue until fetal lung
maturity is reached
– Reassessment of fetal growth is typically made no sooner than 3 to
4 weeks.
– Weekly assessment of umbilical artery Doppler velocimetry and
amnionic fluid volume is combined with periodic non stress testing

22. • Labor and delivery
– a woman with a suspected growth-restricted fetus should undergo
“high-risk” intrapartum monitoring
– frequency of cesarean delivery is increased

23. FETAL OVERGROWTH

24. FETAL OVERGROWTH
• infants exceeding the 90th
percentile for a given gestational week are
usually used as the threshold for macrosomia or large-for-gestational
age (LGA) birthweight
• ACOG concluded that the term macrosomia was an appropriate
appellation for newborns who weigh 4500 g or more at birth

25. RISK FACTORS
• Obesity
• Diabetes—gestational and type 2
• Postterm gestation
• Multiparity
• Large size of parents
• Advancing maternal age
• Previous macrosomic infant
• Racial and ethnic factors

26. MATERNAL AND PERINATAL
MORBDTY
• Increased cesarean delivery rate exceeding 50%
• Rate of shoulder dystocia s as high as 17%
• Increased rates of postpartum hemorrhage, perineal laceration, and
maternal infection

27. DIAGNOSIS
• Sonographic estimation of fetal weight is unreliable, and its routine use
to identify macrosomia is not recommended

28. MANAGEMENT
• Prophylactic labor induction
– obviate further fetal growth and thereby reduce potential delivery
complications
– A review of early term births indicates that elective delivery before
39 weeks’ gestation does not improve maternal outcomes and is
associated with worse neonatal outcomes
– current evidence does not support a policy for early labor induction
before 39 weeks’ gestation or delivery for suspected macrosomia

29. • Elective CS
– The ACOG does not recommend routine cesarean delivery in
women without diabetes when the estimated fetal weight is < 5000
g
– in diabetic women with overgrown fetuses, such a policy of elective
cesarean delivery seems tenable

30. • Prevention of shoulder dystocia
– when fetal overgrowth is suspected, the obstetrician naturally seeks
to balance the risks to the fetus with maternal risks
– elective delivery for the fetus that is suspected to be overgrown is
inadvisable, particularly before 39 weeks’ gestation
– elective cesarean delivery is not indicated when estimated fetal
weight is < 5000 g among women without diabetes and < 4500 g
among women with diabetes