Small for Dates Flashcards
What constitutes pre term delivery?
before 37 weeks
What is the % survival of those born >32 weeks?
91%
What is the % survival of those born at 23 weeks?
19%
What can cause preterm birth?
infection
overdistention - multiple births, polyhydraminos
vascular - placental abruption
intercurrent illness - pyelonephritis/UTI, appendicitis, pneumonia
cervical incompetence
idiopathic
What are risk factors for preterm birth?
previous pre term labour uterine abnormalities parity = 0 or >5 drugs - esp cocaine multiple babies age - teenages low BMI <20 smoking
What consitutes small for gestational age?
estimated foetal weight or abdominal circumference <10th centile
What can cause a baby to be small for gestational age?
intrauterine growth restriction - failure to meet growth potential
low birth weight - below 2.5kg
What are the risk factors for being small for gestational age?
maternal age >40 smoker >11 cigarettes per day parental or maternal SGA daily vigorous exercise low PAPP-A BMI >35 antiphospholipid syndrome known large fibroids
When are symphyseal-fundal heights measured?
24 weeks
How are small for dates diagnosed?
measurement of fetal abdominal circumference then combine with head circumference +/- femur length to give estimated fetal weight
When are women given a uterine artery doppler?
20 weeks
What is the role of uterine artery doppler?
primary tool for monitoring SGA baby
measures the resistance of the uterine artery - should be low
if there is resistance then they are at risk of SGA and hypertensive disease
What are the consequences of intrauterine growth restriction in labour?
risk of hypoxia
What are the consequences of intrauterine growth restriction postnatally?
hypoglycaemia hypothermia hyperbilirubineamia effects of asphyxia polycythaemia abnormal neurodevelopment risk of stillbirth
What are the clinical features of intrauterine growth restriction?
reduced liquor
reduced fetal movements
fundal height less than expected
How is intrauterine growth restriction investigated?
biophysical assessement - scored out of 10
assessment of growth
cardiotography
doppler ultrasound
When should a SGA baby be delivered?
37 weeks if all well
When should an SGA baby be delivered earlier than 37weeks by c/section?
if growth becomes static
abnormal umbillical artery doppler
normal umbillical artery doppler with abnormal Middle Cerebrel Artery between 32-37 weeks or abnormal ductus venous betwen 24-34 weeks
What else should be given to help SGA babies?
steroids to promote fetal lung maturity if before 36 weeks
magnesium sulphate 4 hours before delivery if delivered before 32 weeks, reduces chance of seizure and gives neural protection
