Small for Gestational Age Flashcards
What is described as ‘preterm’?
any birth before 37 weeks
extreme pre-term = 24-27+6 weeks
What is the survival rate of a baby born >32 weeks pre-term?
95%
What are some causes of pre-term delivery?
infection over distention - multiple or polyhydraminous intercurrent illness vascular - placental abruption idiopathic cervical incompetence
What are some risk factors for pre-term delivery?
previous pre-term labour multiple parity is 0 or >5 teenager drugs (especially cocaine) smoking low BMI
What does IUGR stand for?
Intra-uterine growth restriction
What does LBW stand for and mean?
Low birth weight = below 2.5kg regardless of gestation
How is SGA picked up at antenatal screening?
symphysis-fundal height less than 10th centile or multiple measurements showing slow or static growth
How do you diagnose SGA?
Measurement of foetal abdominal circumference paired with femur length. can also get liqour volume/ amniotic fluid index/doppler scan
What are the features of poor growth?
Reduced fundal height for gestation
reduced liquor
reduced foetal movement
What are the three broad categories for reasons of SGA?
Maternal factors
Placental factors
Foetal factors
What are the maternal factors that contribute to SGA?
lifestyle (smoking, alcohol, drugs)
BMI <20
age
maternal disease (usually hypertension)
What are the placental factors that contribute to SGA?
infarcts or abruption
usually secondary to hypertension
What is abruption of the placenta?
This is when the placenta starts to detach from the endometrium prematurely - can cause abdo pain, bleeding and contractions.
What are the foetal factors for SGA?
Infection (rubella, CMV, toxoplasma)
congenital (absent kidneys)
chromosomal abnormalities (down’s syndrome)
What are some consequences of IUGR in labour?
increased risk of hypoxia and death
What are the consequences of IUGR post-natally?
Hypoglycaemia effects of asphyxia hypothermia polycythemia hyperbilirubinaemia abnormal neurological development
How do you asses foetal wellbeing?
doppler ultrasound
biophysical assessment
cardiotocography
assessment of growth
What does a biophysical profile look at?
- foetal movements
- foetal heart rate
- foetal lung movements
- liquor volume
What is the scoring system of a biophysical profile?
8-10 = normal (satisfactory) 4-6 = repeat 0-2 = deliver
What does the umbilical artery doppler look at?
placental resistance to flow (USS)
What will the MCA doppler look at and why?
Foetal middle cerebral artery to look at resistance to flow. Will be good indicator of foetal cardiac stress, foetal anaemia or hypoxia
What is normal in MCA doppler?
for resistance to be high
What is abnormal in MCA doppler?
for resistance to flow to be low
What should be given if considering a pre-term delivery?
Steroids and magnesium sulphate
Why do you give magnesium sulphate and steroids in pre-term labour?
Magnesium sulphate = for neuroprotection of the foetus
Steroids = to aid development and maturation of the foetal lungs (should be given multiple injections if possible)
What are tocolytic drugs?
these are drugs that will slow/hault labour
