FGR/SGA Flashcards
(41 cards)
Definition of SGA and FGR.
- Small for gestational age (SGA) Estimated fetal weight/birthweight less than 10th centile
- Fetal Growth Restriction (FGR) A fetus that has not reached its growth potential, most commonly due to placental insufficiency. Absolute definition controversial.
• 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?
- 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)
- previous obstetric history (3x increased risk)
- 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)
Prevention
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?
.Raised BMI large fibroids prev SGA HTN disorder Multiple pregnancy
Suspicion FGR, which investigations?
PET screen including urine,
USS growth +/- dopplers,
CTG,
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
E.g:
- 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?
20-24/40
Significance of abnormal uterine artery doppler?
Those with very abnormal uterine artery dopplers have a 60% risk of developing SGA/PET that requires delivery <34/40.
Should have regular scans and maternal surveillance.
List maternal medical conditions that predispose to SGA:
- Hypertensive disease
- Renal disease
- Diabetes
- Antiphospholipid syndrome
- Maternal history of SGA
List current pregnancy complications/developments that predispose to SGA:
- Preeclampsia
- First trimester bleeding
- Placenta abruption
- APH
- Gestational HTN
- Teratogenic exposure
- Low PAPP-A <0.4 MoM
- Echogenic bowel
List maternal risk factors that predispose to SGA:
- Low BMI
- High BMI
- AMA
- Nulliparity
- Smoking
- Substance abuse
- IVF
- Poor diet
- Excessive exercise
- Previous SGA
- Previous stillbirth
- Short interpregnancy interval
If UAPI is abnormal in an SGA fetus but delivery is not indicated, how often should you repeat the UAPI?
- Twice weekly if forward EDF.
- Daily if absent or reversed EDF.
List the benefits of UAPI surveillance (4):
- Reduction in perinatal deaths RR 0.71
- Reduction in IOLs RR 0.89
- Reduction in Caesarean section RR 0.90
- Reduced use of antenatal resources (monitoring occasions, hospital admissions, inpatient stay).
In an SGA fetus with normal UAPI, how often would you repeat the UAPI?
- Every 14 days.
When does RCOG recommend delivery of an SGA fetus with static growth over 3 weeks (UAPI normal or abnormal but with forward EDF)?
After 34 weeks.
At what gestation should an SGA fetus with reversed EDF but normal DV doppler be delivered by?
30-32 weeks
At what gestation should an SGA fetus with absent EDF but normal DV doppler by delivered by?
32-34 weeks
