Fetal Growth Restriction

Question 1

How do you define fetal growth restriction?

Answer 1

EFW or AC < 10th %tile

Question 2

Which ultrasound measurement is the most sensitive for FGR?

Answer 2

AC

Question 3

How is a cerebellar measurement useful in FGR?

Answer 3

It is an independent measurement of growth restriction

Question 4

What is your differential diagnosis for early-onset FGR?

Answer 4

Maternal HTN
Placental dysfunction
Genetic abnormalities

Question 5

What is the cause of late-onset FGR?

Answer 5

Placental insufficiency

Question 6

How do you work up the patient with FGR diagnosed in the second trimester?

Answer 6

CBC, CMP, TSH, FT4, UDS and urine P/C ratio

Serial US with UA dopplers

Question 7

When do you recommend a genetic workup in the setting of FGR?

Answer 7

FGR is seen with poly, malformation or both OR FGR diagnosed at < 32 weeks

Question 8

If the patient pursues diagnostic studies, what infection work-up should you add to the study?

Answer 8

CMV

Don’t test for toxo, rubella or herpes in the absence of other risk factors

Question 9

Antepartum testing regimen for a patient with FGR

Answer 9

Elevated Dopplers (decreased EDV) (> 95%tile) or severe GR (<3rd %tile) –> weekly UA Dopplers –> delivery at 37 weeks

AEDV –> 2-3/week UA Dopplers –> delivery at 33-34 weeks

REDV –> hospitalization, steroids, NST 1-2/day, delivery depending on clinical status –> delivery at 30-32 weeks

Question 10

What is the role of Doppler studies in the management of FGR?

Answer 10

predicts perinatal outcome

Question 11

What does an elevated SD ratio indicate?

Answer 11

The amount of resistance in the placental vasculature

Question 12

Describe how you perform umbilical artery Doppler studies.

Answer 12

A systolic/diastolic flow taken from the free-floating portion of the umbilical cord artery with an angulation not > 30 degree

Question 13

What does absent or reversed diastolic flow in the umbilical artery indicate?

Answer 13

It is a strong indication of placental insufficiency.

With increased UA index, 30% of villous vessels are abnormal vs 60-70% with AEDF or REDF, 60-70%

AEDF suggests 50-80% intrauterine hypoxia

Question 14

What does absent or reversed diastolic flow in the ductus venosus indicate?

Answer 14

Absent (20%) vs reversed (46%) associated with stillbirth

Question 15

Why does oligohydramnios develop on FGR?

Answer 15

Shunting of fetal blood away from the kidneys to more vital organs. Decreased renal perfusion leading to reduced urine production which leads to oligohydramnios

Question 16

Trial of umbilical and fetal flow in Europe (TRUFFLE )trial:

Answer 16

• Evaluated DV changes and used this to guide delivery in severely preterm growth restricted fetuses
• Control group used BPP testing
• Outcome was survival without neurodevelopment impairment
• Results- No significant difference in outcome between the two groups

Question 17

PORTO trail

Answer 17

• Evaluated the role of multi-vessel Doppler analysis in the setting of growth restriction
• showed multiple patterns od doppler deterioration may occur in the growth restricted fetus
• 10x RR of adverse outcome (IVH, PVL, NEC, hypoxic-ischemic encephalopathy, bronchiopulmonary dysplasia, death) with abnormal CPR (cerebral:umbilical PI ratio)