Fetal growth Flashcards
How do you investigate a small for dates pregnancy?
USS for size.
Doppler of umbilical artery - should be low resistance, high resistance indicates growth restriction.
Fetal doppler of MCA - low relative to ductus venosus shows head sparing.
CTG.
How do you define “small for dates”?
Weight lower than the tenth centile for gestational age.
How do you define “IUGR”?
Fetus failing to reach its growth potential - i.e. can be “normal” weight, but still IUGR.
How do you define fetal distress?
Acute situation that may result in fetal damage or death if not reversed.
How do you define fetal compromise?
When conditions for normal growth and neurological development are suboptimal. May be IUGR, but not always (e.g. maternal DM).
What investigations are used to identify “at risk” pregnancies?
Bloods: PAPP-A reduction correlates with chromosomal abnormalities, IUGR, abruption and stillbirth.
Uterine artery doppler: 23wk scan gives indication of resistance - should be low. High resistance in early third trimester correlates with pre-eclampsia, IUGR and abruption.
Cervical scan at 23wks for length.
What factors determine fetal size and therefore IUGR / small for dates?
Constitutional: small mum, nulliparity, asian, female fetus.
Pathological: maternal disease, pregnancy complications, multiple pregnancy, smoking, drugs, infections, malnutrition, congenital abnormalities.
How does IUGR present?
Slowing of symphisiofundal height.
Pre-eclampsia.
O/E: USS shows SFD.
How do you manage a SFD pregnancy?
SFD only: check growth fortnightly.
IUGR at term: SFD with abnormal doppler should be delivered if >36weeks.
IUGR preterm: review twice a week. Only deliver if fetal doppler abnormal. Steroids if <34wks.
At what point is a pregnancy “prolonged”?
42wks.
How do you manage a prolonged pregnancy?
Induce after 41 weeks. Balance of risks isn’t favourable until after 41.
If they don’t want to be induced: daily CTG monitoring and sweeping the cervix to help spontaneous labour.
