Transcript Gynae History Taking - Max Brinsmead MB BS PhD | A

ASSESSMENT OF FETAL
WELLBEING
Max Brinsmead MB BS PhD
May 2015
The fetus is unique because...
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He or she cannot signal health by way of history
We can only examine through his or her mother
Non-invasive evaluation includes...
 Documentation
of size and growth
 Fetal movements & reaction to stimuli
 Fetal heart rate studies using CTG
 Amniotic fluid volume study
 Looking at placental morphology by ultrasound
 Study of blood flow in various fetal and maternal
vessels – Doppler studies
 Placental endocrine studies in maternal blood and urine
Pregnancies can be divided into those that are
High or Low Risk of Fetal Compromise/Death
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High risk pregnancies include those that...
 Occur
with conditions known to impair feto-placental
function e.g. Maternal hypertensive conditions, Auto
immune disease
 Depart from normal growth on clinical assessment i.e.
“Too big” or “Too small”
 There is a poor obstetric history
 Multiple pregnancy
 Occur with multiple risk factors e.g. Low social class,
ethnic risk, smoking or other drug use etc
Umbilical Artery Doppler Study
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Upper panel represents
peak (systolic) and trough
(diastolic) flow often
expressed as S/D ratio
Lower panel is constant
flow through a uterine
vein
UA Doppler reflects
downstream placental
resistance
Is the 1st change to occur
with placental disease
Umbilical Artery Doppler changes with Gestation
Abnormal UA Doppler Flows
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When flow ceases in
the diastolic phase
(AEDF) the S/D ratio is
very high (∞)
Flow may even reverse
in the diastolic phase
(RDF) as shown
opposite
Uterine Artery Dopplers…
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Are of limited use when…
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The fetus is very premature (<30 weeks)
Pregnancy is prolonged (>40 weeks)
It is a low risk pregnancy
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Are useful in High Risk Pregnancies
May be used to prolong pregnancy with
immature fetus and apparent IUGR
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5% will be high but normal
Have a high negative predictive value for fetal death
Will change 4 – 7 days before other changes in
fetal wellbeing e.g. Biophysical Profile
Other Pregnancy Doppler Studies
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Fetal Middle Cerebral Artery
 Resistance
falls as brain-sparing IUGR begins
 Strong correlation with fetal HB
 Of particular use in monitoring intrauterine haemolysis
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Fetal Ductus Venosus
 Resistance
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rises as the placenta deteriorates
Maternal Uterine Arteries
 Increased
resistance with bilateral notching at 12 – 24w
predicts early (but not late) onset pre eclampsia with ≈ 60%
sensitivity
Uterine Artery Doppler
Fetal Biophysical Profile
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Ultrasound for…
 Fetal
Breathing
 Fetal Movements
 Fetal Tone
 Amniotic Fluid Volume
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Non Stress CTG
 Looking
at fetal heart short term variability and
accelerations
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Assigns a score of 0,1,2 to each of these five
measures as with the Apgar Score
Scores ≤ 6 are abnormal
Fetal Biophysical Profile (Manning)
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