Fetal Growth Restriction Flashcards
How do you define fetal growth restriction?
Estimated fetal weight below 10% OR AC below 10%
Which ultrasound measurement is the most sensitive for fetal growth restriction?
Abdominal circumference
How is a cerebellar measurement useful in fetal growth restriction?
Growth restriction vs. abnormal dating
What is your differential diagnosis once fetal growth restriction is identified in the second/third trimester?
-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
How do you work up the patient with FGR diagnosed in the second/third trimester?
- detailed anatomy survey - amniocentesis for karyotype, PCR - umbilical doppler - biophysical profile Third trimester: - dopplers - growth - antenatal testing
How do you manage a patient with FGR diagnosed in the second/third trimester?
- anatomy - amniocentesis - growth - weekly biophysical profile @ 24 weeks or when ready for intervention Third trimester: - growth - biophysical profile (twice weekly) - dopplers (twice weekly)
When do you recommend a genetic workup in the setting of FGR?
- growth restriction with associated anomalies or polyhydramnios - early growth restriction less than 32 weeks **** 2-5% are due to chromosomal abnormality****
If you are to perform a genetic workup for FGR, what workup will you perform?
- FISH - karyotype reflex to CMA - amniocentesis after 15 weeks
If amniocentesis is done for FGR, what studies do you send on the fluid?
- karyotype reflex to CMA
When do you recommend an infection workup in the setting of FGR?
- maternal history of infection - periventricular calcification - liver calcification - Echogenic bowel/kidneys - hydrops faetalis
What infection workup do you perform for FGR?
- cytomegalovirus - toxoplasmosis - parvovirus B19 - rubella - varicella - syphilis
Describe your antepartum testing regimen for a patient with FGR.
-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
What is the role of doppler studies in the management of FGR?
Predicts perinatal outcome
What does an elevated S/D ratio indicate?
Increased pressure and resistance in the umbilical artery
Describe how you perform umbilical artery doppler studies.
- 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)
What does absent or reversed diastolic flow in the umbilical artery indicate?
- 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)
How do you manage a patient with absent diastolic flow in the umbilical artery at 26 weeks and 36 weeks?
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
How do you manage a patient with reversed diastolic flow in the umbilical artery at 26 weeks and 36 weeks?
- 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
What does absent or reversed diastolic flow in the ductus venosus indicate?
Diastolic dysfunction of the heart. See reverse flow in the inferior vena cava with atrial contraction
When do you perform ductus venous dopplers?
Low end diastolic velocity
Describe how you follow a patient in the hospital for absent or reversed flow in the umbilical artery?
- 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
Why does oligohydramnios develop in FGR?
Decreased perfusion the renal leads to decrease urine production. Blood flow is shunted to the brain, adrenals
When do you recommend delivery for FGR?
-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
What are indications for delivery in a patient with FGR?
- non reassuring fetal monitoring - biophysical profile < 6/8 - no growth in two (2) weeks - reverse dopplers in severe preeclampsia
How is FGR diagnosed in a multiple gestation?
Traditional way and EFW discordance > 20%
What is your differential diagnosis when FGR is diagnosed in a single fetus of a monochorionic twin gestation?
- TTTS/TAPS/TRAP - placental insufficiency - selective IUGR due to unequal sharing of the placenta
What is your differential diagnosis when FGR is diagnosed in a single fetus of a dichorionic twin gestation?
- bilateral renal agenesis - chromosomal / syndrome causes - familial causes - placental causes
What workup do you perform when FGR is diagnosed in a single fetus of a twin gestation?
- anatomy - fetal growth - weekly bpp - amniocentesis if applicable
How do you counsel the patient about the risks of FGR in a single twin?
- 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%)
How do you follow a twin gestation when growth restriction has been diagnosed in one or both of the twins?
Doppler / biophysical profile or both
What is the significance of discordant twin growth?
- 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
How do you define small for gestational age?
newborns with birth weight less than 10th% for GA
Long term sequelae of fetal growth restriction?
Childhood: cognitive delay Adult: Obesity, type 2 DM, coronary artery disease
What is the sensitivity and specificity of fundal heights in assess growth restriction in the third trimester?
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
The Growth Restriction Intervention Trial (GRIT):
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
Disproportionate Intrauterine Growth Intervention Trial at Term (DiGITAT Trial)
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
Trial of umbilical and fetal flow in Europe (TRUFFLE )trial:
-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
PORTO trail
-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)
Delphi consensus criteria for defining early verses late fetal growth restriction
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
Percentage of dysfunctional placental villous tree in absent end diastolic velocity
60-70% of the placental villous tree
