Fetal Growth Restriction

Question 1

How do you define fetal growth restriction?

Answer 1

Estimated fetal weight below 10% OR AC below 10%

Question 2

Which ultrasound measurement is the most sensitive for fetal growth restriction?

Answer 2

Abdominal circumference

Question 3

How is a cerebellar measurement useful in fetal growth restriction?

Answer 3

Growth restriction vs. abnormal dating

Question 4

What is your differential diagnosis once fetal growth restriction is identified in the second/third trimester?

Answer 4

-maternal chronic disease -maternal nutrition deficit - 600kcal/d - chromosome abnormality - infection (cytomegalovirus, toxoplasmosis, parvovirus B19) - placental mosaic / chorioangioblastoma/ abruption - medication (i.e. valproic acid) or drug (alcohol, cocaine, narcotics) exposure Third trimester: - familial - placental insufficiency

Question 5

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

Answer 5

• detailed anatomy survey - amniocentesis for karyotype, PCR - umbilical doppler - biophysical profile Third trimester: - dopplers - growth - antenatal testing

Question 6

How do you manage a patient with FGR diagnosed in the second/third trimester?

Answer 6

• anatomy - amniocentesis - growth - weekly biophysical profile @ 24 weeks or when ready for intervention Third trimester: - growth - biophysical profile (twice weekly) - dopplers (twice weekly)

Question 7

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

Answer 7

• growth restriction with associated anomalies or polyhydramnios - early growth restriction less than 32 weeks **** 2-5% are due to chromosomal abnormality****

Question 8

If you are to perform a genetic workup for FGR, what workup will you perform?

Answer 8

• FISH - karyotype reflex to CMA - amniocentesis after 15 weeks

Question 9

If amniocentesis is done for FGR, what studies do you send on the fluid?

Answer 9

• karyotype reflex to CMA

Question 10

When do you recommend an infection workup in the setting of FGR?

Answer 10

• maternal history of infection - periventricular calcification - liver calcification - Echogenic bowel/kidneys - hydrops faetalis

Question 11

What infection workup do you perform for FGR?

Answer 11

• cytomegalovirus - toxoplasmosis - parvovirus B19 - rubella - varicella - syphilis

Question 12

Describe your antepartum testing regimen for a patient with FGR.

Answer 12

-3-9%ile weekly dopplers, if stable then monthly dopplers -<3%ile then weekly dopplers/bpp with growth every 2 weeks -absent then twice weekly bpp/dopplers -reverse admit to the hospital *** hospitalization with daily non stress tests and twice weekly biophysical profile with dopplers with absent and reverse

Question 13

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

Answer 13

Predicts perinatal outcome

Question 14

What does an elevated S/D ratio indicate?

Answer 14

Increased pressure and resistance in the umbilical artery

Question 15

Describe how you perform umbilical artery doppler studies.

Answer 15

• color doppler on umbilical artery (free floating umbilical cord) - pulse wave doppler with interrogation box at bottom of the sampled cord (less angulated; less than 30 degrees)

Question 16

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

Answer 16

• low end diastolic velocity - increased pressure in the umbilical artery - increasing impedance - indication of placental insufficiency (absent/reverse suggest 50-80% of fetuses have hypoxia and 60% of villous vessels are abnormal. Increased have 30% abnormal villous vessels)

Question 17

How do you manage a patient with absent diastolic flow in the umbilical artery at 26 weeks and 36 weeks?

Answer 17

at 26 weeks: - admit to the hospital - 2x-3x daily non stress test - biophysical profile and dopplers twice weekly - deliver at 33-34 weeks if stable otherwise deliver with abnormal biophysical profile, non stress test, no growth in two (2) weeks at 36 weeks: - delivery

Question 18

How do you manage a patient with reversed diastolic flow in the umbilical artery at 26 weeks and 36 weeks?

Answer 18

• admit to the hospital - 2x-3x daily non stress test - daily doppler with biophysical profile - deliver at 32 weeks if stable otherwise deliver with abnormal biophysical profile, non stress test, no growth in two (2) weeks 36 weeks? - delivery

Question 19

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

Answer 19

Diastolic dysfunction of the heart. See reverse flow in the inferior vena cava with atrial contraction

Question 20

When do you perform ductus venous dopplers?

Answer 20

Low end diastolic velocity

Question 21

Describe how you follow a patient in the hospital for absent or reversed flow in the umbilical artery?

Answer 21

• admit to the hospital - 2x-3x daily non stress test - daily doppler with biophysical profile - deliver at 32 weeks if stable otherwise deliver with abnormal biophysical profile, non stress test, no growth in two (2) weeks

Question 22

Why does oligohydramnios develop in FGR?

Answer 22

Decreased perfusion the renal leads to decrease urine production. Blood flow is shunted to the brain, adrenals

Question 23

When do you recommend delivery for FGR?

Answer 23

-1) Isolated FGR between the 3 rd -10 th percentile + normal UA Doppler: 38w0d–39w6d -2) Isolated FGR at less 3 rd percentile + normal UA Doppler: 37w0d -3) Delivery at 34w0d–37 6/7 in cases of FGR with additional risk factors -Oligohydramnios -Maternal risk factors DOPPLERS: - 34 with absent - 32 with reverse

Question 24

What are indications for delivery in a patient with FGR?

Answer 24

• non reassuring fetal monitoring - biophysical profile < 6/8 - no growth in two (2) weeks - reverse dopplers in severe preeclampsia

Question 25

How is FGR diagnosed in a multiple gestation?

Answer 25

Traditional way and EFW discordance > 20%

Question 26

What is your differential diagnosis when FGR is diagnosed in a single fetus of a monochorionic twin gestation?

Answer 26

• TTTS/TAPS/TRAP - placental insufficiency - selective IUGR due to unequal sharing of the placenta

Question 27

What is your differential diagnosis when FGR is diagnosed in a single fetus of a dichorionic twin gestation?

Answer 27

• bilateral renal agenesis - chromosomal / syndrome causes - familial causes - placental causes

Question 28

What workup do you perform when FGR is diagnosed in a single fetus of a twin gestation?

Answer 28

• anatomy - fetal growth - weekly bpp - amniocentesis if applicable

Question 29

How do you counsel the patient about the risks of FGR in a single twin?

Answer 29

• preterm delivery - growth restriction of second twin - IUFD ——> can cause neurologic damage (3% didi, 15% monodi) - IUFD ——> can cause death in the other twin (1%, 18%)

Question 30

How do you follow a twin gestation when growth restriction has been diagnosed in one or both of the twins?

Answer 30

Doppler / biophysical profile or both

Question 31

What is the significance of discordant twin growth?

Answer 31

• discordance without growth restriction is expected to have a good prognosis - discordance with restriction is seven (7) times more likely to have major neonatal morbidity

Question 32

How do you define small for gestational age?

Answer 32

newborns with birth weight less than 10th% for GA

Question 33

Long term sequelae of fetal growth restriction?

Answer 33

Childhood: cognitive delay Adult: Obesity, type 2 DM, coronary artery disease

Question 34

What is the sensitivity and specificity of fundal heights in assess growth restriction in the third trimester?

Answer 34

Based on one fundal height measurement at 32–34 weeks: -Sensitivity ~ 65-85% for detecting the growth-restricted fetus -Specificity ~ 96% for detecting the growth-restricted fetus *** not accurate in patients with uterine fibroids Screen starting at 24 weeks. -Discrepancy in GA weeks and fundal height measurement of > 3 cm is cutoff

Question 35

The Growth Restriction Intervention Trial (GRIT):

Answer 35

Population: FGR between 24-36 weeks unknown benefit of delivery

Intervention: Early delivery group (delivery within 48 hours)

Control: Delayed group (antepartum surveillance until felt delivery shouldn’t be delayed) Average 4-day difference in delivery between early verses delayed group

Outcome: neonatal morbidity

Conclusion: More IUFD in delay group but less neonatal death. No difference in motor or intellectual disabilities at 6, 12 yrs out

***Betamethasone administration rates were similar for both groups

Question 36

Disproportionate Intrauterine Growth Intervention Trial at Term (DiGITAT Trial)

Answer 36

Population: FGR fetuses at greater than 36w0d

Intervention: Delivery now (0.9 days)

Control: Expectant w/ delivery only if other indication arose (10.1 days)

Outcome: Adverse neonatal outcome

Conclusion: -No difference between outcomes (cesarean section, composite adverse neonatal outcome - death, 5 min APGAR <7, pH <7.05, NICU admit)

• Birth weight slightly lower in the expectant group
• Not powered to identify a difference in perinatal death between the groups

Question 37

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

Answer 37

-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 38

PORTO trail

Answer 38

-Evaluated the role of multi-vessel Doppler analysis in the setting of growth restriction -showed multiple patterns of 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 <1 (cerebral:umbilical PI ratio)

Question 39

Delphi consensus criteria for defining early verses late fetal growth restriction

Answer 39

Question 40

Trend for postnatal morbidities depending on gestational age at birth: this is why 32 weeks is favored for delivery in severe casees of growth restriction

Answer 40

Question 41

Percentage of dysfunctional placental villous tree in absent end diastolic velocity

Answer 41

60-70% of the placental villous tree