#204 Fetal Growth Restriction Flashcards
What is the definition of fetal growth restriction per ACOG?
Estimated fetal weight less than the 10th percentile for gestational age
What is the definition of small for gestational age according to ACOG?
Newborns whose birth weight is less than the 10th percentile for gestational age
What maternal medical conditions can lead to fetal growth restriction?
Pregestational diabetes mellitus, renal insufficiency, autoimmune disease (eg, SLE), cyanotic cardiac disease, pregnancy-related HTN diseases of pregnancy (eg, CHTN, GTN, PEC), antiphospholipid antibody syndrome, substance use and abuse (eg, tobacco, alcohol, cocaine, narcotics)
Does malaria affect fetal weight?
Yes, risk of growth restriction
Does cytomegalovirus affect fetal weight?
Yes, risk of growth restriction
Does rubella affect fetal weight?
Yes, risk of growth restriction
Does toxoplasmosis affect fetal weight?
Yes, risk of growth restriction
Does syphilis affect fetal weight?
Yes, risk of growth restriction
Is factor V Leiden mutation associated with fetal growth restriction?
No
Is Prothrombin mutation associated with fetal growth restriction?
No
Is methylenetetrahydrofolate reductase gene mutation associated with fetal growth restriction?
No
How does tobacco use affect the risk (fold increase/decrease) of small for gestational age?
3.5-fold increase
Does additional nutrient intake in the absence of true maternal malnutrition increase weight and/or improve outcomes in cases of suspected fetal growth restriction?
No high-quality evidence to suggest it does
Twin pregnancies account for what % of live births in the US?
2-3%
Twin pregnancies account for what % of adverse neonatal outcomes in US?
10-15% [only 2-3% of live births]
What is the risk of SGA in twin pregnancies?
As high as 25%
What is the risk of SGA with triplet and quadruplet pregnancies?
60%
What are some classic medications that are associated with fetal growth restriction?
Certain antineoplastic medications (eg, cyclophosphamide), antiepileptic drugs (eg, valproic acid), and antithrombotic drugs (eg, warfarin)
What cases of fetal growth restriction are suspected to be caused by infection?
5-10%
What infection accounts for the most cases of infection-related growth restriction worldwide?
Malaria
Does varicella infection affect fetal weight?
Yes, risk of growth restriction
What % of fetuses with trisomy 13 or 18 have fetal growth restriction?
At least 50%
How often do fetuses with gastroschisis have fetal growth restriction?
Up to 25% of cases
Is fetal growth restriction associated with placenta accreta and/or placenta previa?
No
What placental disorders are associated with fetal growth restriction?
Abruption, infarction, circumvallate shape, hemangioma, and chorioangioma
What umbilical cord abnormalities are associated with fetal growth restriction?
Velamentous or marginal cord insertion. Some studies say single umbilical artery is associated with FGR, others do not.
What % of pregnancies have a single umbilical artery?
1%
Is fetal growth restriction associated with longterm outcomes? If so, what?
Predisposed to development of cognitive delay in childhood and diseases in adulthood (eg, obesity, T2DM, CAD, and stroke)
What is the risk of fetal death (%) in fetuses weighing <10%tile? How does it compare to background rate?
1.5% (twice the background rate of fetuses of normal growth)
What is the risk of fetal death (%) in fetuses weighing <5%tile?
2.5%
What complications are small-for-gestational-age newborns predisposed to?
Hypoglycemia, hyperbilirubinemia, hypothermia, intraventricular hemorrhage, necrotizing enterocolitis, seizures, respiratory distress syndrome, and neonatal death
What is the sensitivity and specificity of fundal height measurements at 32-34wks gestation for detecting fetal growth restriction?
65-85% sensitive; 96% specific
What is the % error of ultrasound EFW in 95% of cases?
Up to 20% deviation
How does umbilical artery Doppler velocimetry added to standard antepartum testing in the setting of fetal growth restriction affect outcomes?
Reduces the rate of perinatal death by as much as 29%
How does monitoring flow of ductus venosus affect outcomes in growth restricted fetuses?
Use has not been shown to improve outcomes
When should you start performing fundal height measurements at prenatal visits?
After 24 weeks
With what fundal height to gestational age discrepancy should you investigate further?
Greater than 3
What is the risk of recurrence of a small for gestational age birth?
Approximately 20%
What nutritional and dietary supplemental strategies are recommended for the prevention of fetal growth restriction?
None, they are not effective and not recommended
Does bed rest help prevent fetal growth restriction or reduce the incidence of SGA births?
No
Does timing of onset of fetal growth restriction help assess if it is genetically related?
Yes, fetal growth restriction is more commonly detected earlier if associated with aneuploidy, midtrimester onset is an indication to offer genetic counseling and prenatal diagnostic testing
If fetal growth restriction a reason to offer genetic testing?
Suspicious for genetic abnormalities if:
- early onset
- associated with structural abnormalities on ultrasound
How often should you assess EFW in fetus with growth restriction?
Typically every 3-4 weeks, earliest would be every 2 weeks
Should flow in ductus arteriosis guide timing of delivery in growth restricted fetuses?
Uncertain. TRUFFLE study showed less neurodevelopmental deficiency at 2yrs if delivered based on DV doppler, but associated with increase in perinatal and infant mortality.
When should you deliver a baby with isolated fetal growth restriction?
38w0d to 39w6d
When should you delivery a baby with fetal growth restriction with additional risk factors for adverse oucomes (eg, oligohydramnios, abnormal umbilical artery doppler, maternal risk factors, or comorbidities)?
32w0d to 37w6d. Earlier delivery in this range may be indicated for most severe cases (eg UA reversed end diastolic flow)
Which fetuses with growth restriction are candidates for antenatal corticosteroids?
If delivery is anticipated before 33w6d or if between 34w0d and 36w6d at risk for preterm delivery within 7d and did not receive previous course of antenatal corticosteroids
Which patients with fetal growth restriction should receive magnesium for neuroprotection?
Those delivery before 32 wks
Is fetal growth restriction an indication for cesarean delivery?
No
