Small-for-Gestational-Age Fetus, Investigation and Management Flashcards
who should be assessed for SGA
- All should be assessed at booking for risk factors for SGA fetus/neonate to identify requiring increased surveillance.
What is major risk factor for SGA, what is MX
- major risk factor (Odds Ratio [OR] > 2.0)
- referred for serial ultrasound measurement of fetal size and assessment of wellbeing with umbilical artery Doppler from 26–28 wks of pregnancy.
What is minor risk factor for SGA, what is MX
- three or more minor risk factors
- referred for uterine artery Doppler at 20–24 wks of gestation.
DS marker and SGA predictability
- Second trimester DS markers have limited predictive accuracy for delivery of a SGA neonate.
- low level (< 0.415 MoM) of the first trimester marker PAPP–A should be considered a major risk factor
for delivery of a SGA neonate.
why not uterine artery doppler in high risk population?
In high risk populations uterine artery Doppler at 20–24 wks of pregnancy has a moderate predictive value for severely SGA neonate.
why not uterine artery doppler to be repeated risk assessment?
- If abnormal uterine artery Doppler at 20–24 wks, subsequent normalisation of flow velocity indices is still associated with an increased risk of a SGA neonate.
- Repeating uterine artery Doppler is therefore of limited value.
What is MX of abnormal uterine artery Doppler at 20–24 weeks?
- abnormal uterine artery Doppler at 20–24 weeks (defined as PI > 95th centile) and/or notching should be referred for serial ultrasound measurement of fetal size & assessment of wellbeing with umbilical artery Doppler commencing at 26–28 weeks of pregnancy.
What is MX of normal uterine artery Doppler at 20–24 weeks?
- Women with a normal uterine artery Doppler do not require serial measurement of fetal size and serial
assessment of wellbeing with umbilical artery Doppler unless they develop specific pregnancy complications, for example antepartum haemorrhage or hypertension.
However, they should be offered a scan for fetal size and umbilical artery Doppler during third trimester.
fetal echogenic bowel. & SGA
Serial ultrasound measurement of fetal size and assessment of wellbeing with umbilical artery Doppler
should be offered in cases of fetal echogenic bowel.
Abdominal palpation and predictability of SGA
- Abdominal palpation has limited accuracy for prediction of SGA neonate & should not be routinely performed in this context.
- Serial measurement of SFH is recommended at each antenatal appointment from 24 weeks of pregnancy as this improves prediction of a SGA neonate.
SFH and predictability of SGA
- SFH should be plotted on customised chart rather than population–based chart as this may improve prediction of a SGA neonate.
- Women with single SFH which plots below 10th centile or serial measurements which demonstrate slow or static growth by crossing centiles should be referred for ultrasound measurement of fetal size.
SFH and predictability of SGA & exclusion criteria
- in whom measurement of SFH is inaccurate (BMI > 35, large fibroids, hydramnios) referred for serial assessment of fetal size using ultrasound.
Optimum method of diagnosing a SGA fetus and FGR
AC & EFW
- Fetal AC or EFW < 10th centile can be used to diagnose SGA fetus.
- Use of customised fetal weight reference may improve prediction of SGA neonate & adverse perinatal outcome. In women having serial assessment of fetal size, use of customised fetal weight reference may improve prediction of normal perinatal outcome.
- Routine measurement of fetal AC or EFW in the third trimester
- Routine measurement of fetal AC or EFW in third trimester does not reduce incidence of a SGA neonate nor does it improve perinatal outcome.
- Routine fetal biometry is thus not justified.
Optimum method of diagnosing a SGA fetus and FGR
- Change in AC or EFW
- Change in AC or EFW may improve prediction of wasting at birth (neonatal morphometric indicators)
and adverse perinatal outcome suggestive of FGR.