Transcript Hypertension in Pregnancy at 33 weeks

A Case History of
Hypertension in Pregnancy
Max Brinsmead MB BS PhD
March 2016
Carol is a 36-year old Intensive Care
Nurse who has been trying to have a
baby for 5 years. She conceives
spontaneously and commences antenatal
care in Sydney. During a “weekend away”
in Coffs Harbour she comes to Maternity
feeling a little unwell and asks to have her
BP checked. It is 160/105. The midwife
starts a CTG and asks that you come to
see this patient.
Carol is pregnant with a BP of 160/105
Preeclampsia is sustained
hypertension in the 2nd half of
pregnancy accompanied by
evidence of some other
organ involvement. Returns
to normal after 3m
 Not urgent, but symptoms
are worrying…
 This pregnancy. Other
pregnancies. Personal and
Family medical history. Social
circumstances. Symptoms.


Is this preeclampsia
or pregnancy-induced
hypertension

How urgent is this
review

What further history
do you require
Carol with a BP of 160/105
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Gestation is 33 weeks by dates and early scans
Never pregnant before
All tests thus far, including PAPP-A for triploidy,
are normal
Had “nephritis” aged 6 years but recovered
after 6 weeks
Mother is hypertensive on medication
Married to another nurse. Non smoker. Usually
fit and healthy but just “feels unwell and thought
her BP might be up”
BP in the first trimester was 105–115/60–75
and was 130/80 one week ago
Carol G1P0 at 33 weeks with a BP of 160/105

What examination
would you do

What tests are
desirable

Would you admit
this patient to the
antenatal ward

Repeat BP after resting.
Cardiovascular and
pregnancy examination.
Test urine for protein


FBC, UEC, LFTs, Urate,
Proteinuria quantification,
UMCS
Pregnancy ultrasound
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YES
Carol G1P0 at 33 weeks BP 160/105

Cardiovascular exam is
normal apart from
accentuated 2nd heart
sound. Mild generalized
oedema noted

Symphysis-fundal height
29 cm

Knee jerks are active but
there is no sustained
clonus
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Oedema is no longer
regarded as a sign of
preeclampsia
Because oedema is a
“good sign” in pregnancy

This uterus is small for
dates
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It is normal to have 1-2
beats of clonus but
sustained clonus is a sign
of imminent eclampsia
Carol G1P0 at 33 weeks BP 160/105
Ward test proteinuria +
 HB 128 Hct 0.36 Platelets 231
 UEC and LFT’s normal. S Creat normal.
Urate 0.38
 24-hr urine protein 0.25G (normal <0.3G)
 UMCS – no red/white cells or casts. Culture
negative
 Estimated Fetal Weight (EFW) by ultrasound
<10th centile with evidence of head-sparing
IUGR. Reduced amniotic fluid index.
Umbilical Art. (UA) Dopplers on 95th centile
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Estimated Fetal Weight by Ultrasound
Is made by ultrasonic measurements of
head biparietal diameter (BPD), head
circumference (HC), abdominal
circumference (AC) and Femur Length (FL)
 Has an error of not less than ± 20%
 Fetal growth restriction is either
generalised (symmetrical) or head-sparing
(asymmetrical)
 Asymmetrical IUGR arises from a
redirection of cardiac output by the fetus to
support its vital brain growth

Amniotic Fluid
Is largely composed of fetal urine
 It’s volume is a reflection of fetal urine
output
 Which, in turn, is a reflection of fetal
cardiac output/function, fetal oxygenation
and welfare
 Will be absent if there is renal agenesis or
urine output obstruction
 Is often expressed as the Amniotic Fluid
Index (AFI)
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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
It is the 1st change to
occur with placental
disease
Umbilical Artery Doppler changes
with Gestation
Abnormal UA Doppler Flows
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
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Carol G1P0 33 weeks BP of 160/105 but no
significant proteinuria. Clinical and scan
evidence of IUGR


Is this preeclampsia
Why is that an
important diagnosis

YES

Preeclampsia is an
unpredictable disease with
significant maternal and
fetal morbidity and risk of
mortality
Systems involved in Preeclampsia

Renal
 Significant proteinuria
 Renal failure biochemistry
 Oliguria
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Hepatic
 Elevated transaminases
 Epigastric or RUQ pain
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Haematological
 Thrombocytopenia
 Haemolysis
 DIC
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CNS
 Eclampsia or stroke
 Hyperreflexia with sustained clonus
 Severe headache or visual disturbance
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Cardiovascular
 Pulmonary oedema
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Placental
 IUGR
 Abruption
Carol 33 weeks with preeclampsia in hospital. BP
rises to 180/110 at 6 pm with dull headache. No
sustained clonus
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Does this hypertension
require treatment
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Why
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Aldomet or Labetalol
with a loading dose
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Reduce BP to 120150/80-100 so as not to
further compromise
uterine blood flow
What drug will you use
What BP would you aim
to achieve
Yes
Risk of eclampsia,
cerebral haemorrhage
and pulmonary oedema
Carol 33 weeks with preeclampsia. Over the next
2 days her BP continues to rise, especially at night

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What measures can you
use to control the BP
How will you monitor
fetal wellbeing on a daily
basis
Use drugs to maximum
possible doses. Then add
in other drugs from a
different class
◦ For example, Aldomet +
Labetalol + Nifedipine +
Prazosin
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Fetal movement charts
and non stress
cardiotocography
(CTG)
Antenatal (Non stress) CTG
10–40 min of
continuous FHR
 Tocograph for fetal
movements +
maternal trigger
 Is an assessment of
fetal CNS and cardiac
oxygenation
 High negative
predictive value when
“reactive"
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Carol now 34 weeks. BP difficult to control. She
develops severe epigastric pain and vomiting.
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Deteriorating
preeclampsia with a
significant risk of fits
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Acute liver swelling
stretches its capsule.
Maybe subcapsular
haematoma

AST 240, ALT 115
(NR <70)
What is the most
likely diagnosis

What causes the
pain
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What tests may be
useful
Carol 34 weeks with uncontrolled hypertension and
epigastric pain. Ultrasound shows no further fetal growth
and AEDF with Doppler of the umbilical arteries.
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How will you CURE
this patient
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What steps may be
desirable on behalf of
the baby
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DELIVERY
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A course of
steroids to
promote fetal lung
maturation
Carol 34 weeks with severe preeclampsia and fetal
compromise requires delivery
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How can you deliver
this patient
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Describe the pros
and cons of each
method
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Induction of labour
best for mother but
baby may not tolerate
the hypoxic stress of
contractions. Cervix
may be unfavourable.
Caesarean quick and
best for baby but
riskier for mother and
may compromise her
future deliveries
As preparations are being made for a Caesarean Carol has
a grand mal seizure.You are present as it commences…
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First aid is more
important than drugs
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What do you do
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Protect from injury
Secure an airway
Administer oxygen
Then secure IV access
IV MgSO4 loading
dose and maintain by
infusion
Carol 34 weeks has had an eclamptic fit. MgSO4 continues
by infusion. Her BP is 180/120.

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What drugs are
useful now to lower
BP
What are the risks
from the MgSO4 and
how is that avoided
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IV Hydrallazine or
Diazoxide used most
in Australian practice
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Risk of respiratory and
cardiac arrest. Monitor
urine output,
respirations, O2
saturation, knee jerks
and serum Mg levels
Carol undergoes urgent Caesarean section and is
transferred to Intensive Care for postoperative care
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How long should the
MgSO4 infusion
continue
What are the problems
that may arise from
intensive care
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Not less than 24 hours
after delivery
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Separation of mother
and infant interferes
with bonding and
lactation
Insomnia and stress to
Carol and her relatives
May increase the risk of
thromboembolism
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The baby weighs 1800g and has signs of IUGR.
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What is the most
common neonatal
problem for this
baby
How is it avoided
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Hypoglycaemia due to
depleted glycogen liver
stores

Monitor blood glucose
levels. Early feeding by
suckling or D-tube or
IV glucose may be
required
The baby does well. Carol’s BP still requires treatment
postpartum.
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When would expect
recovery of renal or
hepatic dysfunction
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How about the
hypertension
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What drugs are used
in the control of
hypertension
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24-72 hours but
renal/hepatic function
may get worse before
it gets better
Keep BP <150/100,
drugs may be required
for 6-12 weeks
Any antihypertensive
drug can be used (but
some patients don’t
respond to ACE
inhibitors)
Carol’s BP is normal off all medication by 6 weeks. Tests for
autoimmune disease and thrombophilia are negative
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What is the risk that
she will develop
preeclampsia in a
subsequent pregnancy
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50 – 66%
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Low dose aspirin (100
mg daily preferably
commencing in the 1st
trimester) reduces risk
by >17%
Also use Ca
supplements 1.5G/day
How could that risk be
reduced
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Is Carol at risk of
hypertension in the
future

YES
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