Fetal Growth Restriction

Question 1

what is the definition of fetal growth restriction?

Answer 1

fetal weight <10th percentile for GA as per U/S, and not meeting growth potential as determined by genetic makeup

Question 2

what is the difference between asymmetrical and symmetrical FGR?

Answer 2

asymmetrical - placental insufficiency or other underlying pathology, resulting in fetal blood shunting to vital organs like heart and brain, resulting in asymmetrical growth

symmetrical - these babies may start as asym but as the stressor is constant throughout development, may end up proportionatly small

can also be constitutional if all other causes of symmetrical FGR are r/o

Question 3

what is symmetrical FGR?

Answer 3

all growth parameters are proportionally reduced

Question 4

what is asymmetrical FGR?

Answer 4

abdominal circumference is <10th percentile; other measurements are relatively preserved (may be normal)

Question 5

what are some fetal RF/etiologies for FGR?

Answer 5

1. chromosomal abnormalities
2. multiple gestation
3. fetal infection (cytomegalovirus or toxoplasmosis)
4. any other congenital anomalies/syndrome

Question 6

what are some maternal RF/etiologies for FGR?

Answer 6

1. chronic disease: DM, HTN, kidney disease, lupus, antiphospholipid syndrome
2. substance use, alcohol, smoking, medications
3. extremes of maternal age
4. hx of FGR
5. uterine malformations
6. malnutrition and anemia and sickle cell anemia

Question 7

what are some placental RF/etiologies for FGR?

Answer 7

1. chromosomal placental mosacisim
2. placental anomalies (small placenta)
3. umbilical cord anomalies – single artery

Question 8

general pathophysiology for fetal growth restriction

Answer 8

Placental insufficiency → reduction of maternal-fetal transfer of nutrients → ↓ glucose, AA, and minerals → ↓ deposition of glycogen in liver and muscles and minerals into bones ➔ fetus under stress ➔ blood flow diverted to brain, heart, adrenals, and placenta

Question 9

how do these FGR babies present at birth?

Answer 9

decreased muscle mass and subcut fat

may have a proportionately large or small head

Question 10

what are some short term complications for FGR babies?

Answer 10

premature delivery - respiratory distress, necrotizing enterocolitis, intracranial hemorrhage, postpartum cx like neonatal jaundice, hypoglycemia, and polycythemia

Question 11

what are some long term complications for FGR babies?

Answer 11

may have short stature in adulthood

they are at an increased risk of having neurological development disorders (learning disabilities, behavioural problems/hyperactivity) and other chronic diseases (cardiovascular, obesity, renal disease)

Question 12

what ix do you perform to monitor baby wellness at prenatal visits?

Answer 12

1. serial fundal height measurements
2. if the fundal height does not match GA, then consider doing fetal u/s to measure the fetus - head circumference, abdo circumference, femur length
3. consider doing an umbilical artery doppler velocimetry scan to visualize the blood flow of the umbilical artery and baby
4. consider doing a biophysical profile - 30 min u/s evaluating fetal movement, breathing, tone, and amniotic fluid
5. could also do a nonstress test which records fetal heartbeat and uterine contractions, but not always done

Question 13

how do you manage a FGR pregnancy?

Answer 13

1. serial monitoring w/ BPP and umbilical artery doppler velocimetry
2. consider delivery if umbilical artery doppler velocimetry is abnormal
3. if <34 then corticosteroids and mag sulfate
4. otherwise, continue with normal prenatal care and delivery