Flashcards in FGR/SGA Deck (15)
• Fetal Growth Restriction (FGR) A fetus that has not reached its growth potential. (in practice, small for gestational age (SGA) is often used as a proxy for FGR)
• Small for gestational age (SGA) Estimated fetal weight/birthweight less than 10th centile
• Severe FGR: Often SGA <3rd centile, features such as oligo/abnormal dopplers etc (oligohydramnios late sign of poor placental perfusion).
• Early onset: <32 weeks gestation
• Late onset: >32 weeks
When to suspect suboptimal fetal growth?
• The abdominal circumference on the population (ASUM) scan chart is <5th centile
• Discrepancy in HC and AC
• AC is >5th but is crossing centiles by > 30th centile e.g. reduction from 50th centile to 20th centile
• A change in AC of <5mm over 14 days
• EFW on GROW is <10th
• EFW on GROW is crossing centiles with > one third reduction in EFW percentile
What information should be gained from women with suspected FGR?
1. maternal characteristics and medical history (a history of a previous SGA or stillborn infant; maternal age >40; maternal or paternal history of being SGA at birth; smoking >10 cigarettes daily; using cocaine, and maternal diseases associated with increased risk (e.g. chronic hypertension, renal disease, diabetes with vascular disease, anti-phospholipid syndrome)
2. previous obstetric history (3x increased risk)
3. risk factors that may arise in pregnancy (low PAPP-A, heavy early pregnancy bleeding, fetal echogenic bowel, preeclampsia, severe pregnancy-induced hypertension, unexplained APH or abruption and low gestational weight gain)
Start low dose aspirin (100-150mg) in those with risk factors for FGR if <16/40
What factors indicate regular growth scans rather than relying on SFH?
Suspicion FGR, which investigations?
PET screen including urine,
USS growth +/- dopplers,
TORCH and karyotyping if early onset severe SGA (especially if uterine/umbilical dopplers normal),
Consider fetal abnormality/chromosomal causes also in early onset.
How to manage babies once born if the have FGR/SGA?
- Monitoring and maintenance of oxygenation, temperature and blood glucose levels.
- Paired cord blood gases can be undertaken to assess acid base status at birth.
- In the care of the preterm growth restricted neonate, consider specific issues relating to prematurity such as lung disease, increased risk of infection, neurological complications and necrotising enterocolitis.
- Term babies at increased risk of hypothermia, hypoglycaemia and jaundice
Advice for future pregnancies?
Adjust any modifiable risk factors (e.g. smoking), aspirin for future pregnancies, serial growth scans
Uterine artery doppler
What does umbilical artery doppler measure?
Umbilical artery Doppler provides a measure of placental resistance.
What does MCA doppler measure?
MCA provides information about cerebral redistribution of blood flow, abnormal MCA is a response to hypoxia and means there is an increased proportion of flow to the brain- brain sparing.
What does DV doppler measure?
DV provides information about cardiac redistribution- abnormal DV associated with imminent fetal death.
Technique for UA doppler assessment?
• Free loop of cord (away from insertions)
• No fetal body, limb or breathing movements
• Identify UA with colour Doppler
• Measure FVW with pulsed Doppler
- set gate size to cover entire vessel
- Ideally display arterial and venous waveforms simultaneously
• Adjust Doppler gain, baseline, scale and sweep speed to produce a good quality FVW
• Analyse FVW to calculate S/D ratio or PI
Indications for measuring uterine artery doppler
• In women assessed to be at high risk of severe or early SGA
- previous early SGA with delivery <34/40,
- antiphospholipid syndrome,
- severe chronic HTN,
- maternal renal disease
- an autoimmune condition)
Which gestation to perform uterine artery dopplers as screening?