Definitions
Fetal growth restriction is defined as estimated fetal weight or abdominal circumference below this percentile for gestational age
10th percentile
Approximately what percentage of fetal growth restriction cases are due to chromosomal abnormalities or congenital malformations?
~20%
When fetal growth restriction is diagnosed, this type of ultrasound exam is recommended to evaluate for structural anomalies
Detailed anatomy scan
This is the primary Doppler study used for surveillance after diagnosis of fetal growth restriction
Umbilical artery doppler
Isolated fetal growth restriction with normal Dopplers and EFW between the 3rd and 10th percentile
38w0d to 39w0d
This percentile cutoff defines “severe” fetal growth restriction and is associated with markedly increased perinatal risk
This category of fetal growth restriction is more likely to follow a predictable Doppler deterioration pattern involving the umbilical artery and ductus venosus
early-onset FGR
In pregnancies with FGR and a fetal anomaly or polyhydramnios at any gestational age, or in unexplained isolated fetal growth restriction diagnosed before 32 weeks, this diagnostic test should be offered
chromosomal microarray analysis
An abnormal umbilical artery Doppler is defined as an index above this percentile
95th percentile
FGR with elevated dopplers but not absent or reversed end diastolic flow
37w0d or at diagnosis if term
Early-onset fetal growth restriction is defined as diagnosis before this gestational age
32w0d
Despite prior teaching, this classification of FGR based on head-to-abdominal circumference ratios has not been shown to independently predict outcomes?
symmetry
Routine screening for these three infections is not recommended in FGR without risk factors
Toxoplasmosis, rubella, herpes
These two Doppler findings represent progressively worsening placental insufficiency and are associated with increased perinatal mortality
Absent end-diastolic flow
Reversed end-diastolic flow
FGR with absent end-diastolic flow
33w0d to 34w0d
Why does the standard definition of FGR using EFW <10th percentile lack specificity for true pathology
Many fetuses are constitutionally small but healthy, EFW alone does not distinguish between this and FGR
Why has the strategy of diagnosing fetal growth restriction based on deviation from an individual fetal growth trajectory (rather than percentile cutoffs) not been widely adopted in clinical practice?
This strategy requires patients to obtain multiple ultrasounds without evidence of benefit in studies
In cases of unexplained fetal growth restriction where diagnostic testing is pursued, this infection should be evaluated using PCR
CMV
Routine Doppler assessment of these vessels is not recommended for standard clinical management of FGR
Ductus venosus
Middle cerebral artery
Uterine artery
FGR with reversed end diastolic flow
30w0d to 32w0d
What is the diagnosis for a patient at 35w3d with EFW in the 5th percentile and AC <1st percentile?
FGR (not severe)
Which key limitation of customized fetal growth standards has prevented their widespread adoption over population-based references such as Hadlock?
They have not been shown to improve detection of FGR or perinatal outcomes compared with population-based standards
In pregnancies with reversed end-diastolic flow, management includes:
Hospitalization
Steroids
NST 1-2x a day
When absent end-diastolic flow is detected, umbilical artery Doppler should be performed with this increased frequency
up to 3x a week
FGR with concurrent condition (oligo, PEC, cHTN, etc)
34w0d to 37w6d