A Case History of A Case History of Hypertension in Hypertension in

PregnancyPregnancy

Max Brinsmead MB BS PhDApril 2014

Carol is a 36-year old Intensive Carol is a 36-year old Intensive Care Nurse who has been trying Care Nurse who has been trying to have a baby for 5 years. She to have a baby for 5 years. She conceives spontaneously and conceives spontaneously and commences antenatal care in commences antenatal care in Sydney. During a “weekend Sydney. During a “weekend away” in Coffs Harbour she comes away” in Coffs Harbour she comes to Maternity feeling a little unwell to Maternity feeling a little unwell and asks to have her BP checked. and asks to have her BP checked. It is 160/105. The midwife starts a It is 160/105. The midwife starts a CTG and asks that you come to CTG and asks that you come to see this patient. see this patient.

Carol is pregnant with a BP of Carol is pregnant with a BP of 160/105160/105

Is this preeclampsia or pregnancy-induced hypertension

How urgent is this review

What further history do you require

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.

Carol with a BP of 160/105Carol with a BP of 160/105Gestation is 33 weeks by dates and early

scansNever 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 medicationMarried 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 Carol G1P0 at 33 weeks with a BP of 160/105160/105

What further information do you require

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

YES

Carol G1P0 at 33 weeks BP 160/105Carol 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

Oedema is no longer regarded as a sign of preeclampsia

Because oedema is a “good sign” in pregnancy

This uterus is small for dates

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 160/105Carol G1P0 at 33 weeks BP 160/105

Ward test proteinuria +HB 128 Hct 0.36 Platelets 231UEC and LFT’s normal. S Creat normal.

Urate 0.3824-hr urine protein 0.25G (normal

<0.3G)UMCS – no red/white cells or casts.

Culture negativeEstimated Fetal Weight (EFW) by

ultrasound <10th centile with evidence of head-sparing IUGR. Reduced amniotic fluid index. Umbilical Art. (UA) Dopplers on 95th centile

Estimated Fetal Weight by Estimated Fetal Weight by UltrasoundUltrasound

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 to support vital brain growth

Amniotic Fluid Amniotic Fluid

Is largely composed of fetal urineIt’s volume is a reflection of fetal

urine outputWhich, 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)

Umbilical Artery Doppler Umbilical Artery Doppler StudyStudy

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 Umbilical Artery Doppler changes with Gestationchanges with Gestation

Abnormal UA Doppler Abnormal UA Doppler FlowsFlows

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

Carol G1P0 33 weeks BP of 160/105 Carol G1P0 33 weeks BP of 160/105 but no significant proteinuria. Clinical but no significant proteinuria. Clinical and scan evidence of IUGRand scan evidence of IUGR

Is this preeclampsia

Why is that an important diagnosis

YES

Preeclampsia is an unpredictable disease with significant maternal and fetal mortality and morbidity

Systems involved in Systems involved in PreeclampsiaPreeclampsia

Renal Significant proteinuria Renal failure biochemistry Oliguria

Hepatic Elevated transaminases Epigastric or RUQ pain

Haematological Thrombocytopenia Haemolysis DIC

CNS Eclampsia or stroke Hyperreflexia with sustained clonus Severe headache or visual disturbance

Cardiovascular Pulmonary oedema

Placental IUGR Abruption

Carol 33 weeks with preeclampsia in Carol 33 weeks with preeclampsia in hospital. BP rises to 180/110 at 6 pm hospital. BP rises to 180/110 at 6 pm with dull headache. No sustained clonus with dull headache. No sustained clonus

Does this hypertension require treatment

Why

What drug will you use

What BP would you aim to achieve

YesRisk of eclampsia,

cerebral haemorrhage and pulmonary oedema

Aldomet or Labetalol with a loading dose

Reduce BP to 120-150/80-100 so as not to further compromise uterine blood flow

Carol 33 weeks with preeclampsia. Over Carol 33 weeks with preeclampsia. Over the next 2 days her BP continues to rise, the next 2 days her BP continues to rise, especially at nightespecially at night

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

Fetal movement charts and non stress cardiotocography (CTG)

Antenatal (Non stress) Antenatal (Non stress) CTGCTG

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"

Carol now 34 weeks. BP difficult to Carol now 34 weeks. BP difficult to control. She develops severe epigastric control. She develops severe epigastric pain and vomiting. pain and vomiting.

What is the most likely diagnosis

What causes the pain

What tests may be useful

Deteriorating preeclampsia with a significant risk of fits

Acute liver swelling stretches its capsule. Maybe subcapsular haematoma

AST 240, ALT 115 (NR <70)

Carol 34 weeks with uncontrolled hypertension Carol 34 weeks with uncontrolled hypertension and epigastric pain. Ultrasound shows no and epigastric pain. Ultrasound shows no further fetal growth and AEDF with Doppler of further fetal growth and AEDF with Doppler of the umbilical arteries.the umbilical arteries.

How will you CURE this patient

What steps may be desirable on behalf of the baby

DELIVERY

A course of steroids to promote fetal lung maturation

Carol 34 weeks with severe preeclampsia and Carol 34 weeks with severe preeclampsia and fetal compromise requires deliveryfetal compromise requires delivery

How can you deliver this patient

Describe the pros and cons of each method

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 As preparations are being made for a Caesarean Carol has a grand mal seizure. You Caesarean Carol has a grand mal seizure. You are present as it commences…are present as it commences…

What do you do

First aid is more important than drugs

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. Carol 34 weeks has had an eclamptic fit. MgSOMgSO4 4 continues by infusion. Her BP is continues by infusion. Her BP is 180/120.180/120.

What drugs are useful now to lower BP

What are the risks from the MgSO4 and how is that avoided

IV Hydrallazine or Diazoxide used most in Australian practice

Risk of respiratory and cardiac arrest. Monitor urine output, respirations, O2 saturation, knee jerks and serum Mg levels

Carol undergoes urgent Caesarean section and Carol undergoes urgent Caesarean section and is transferred to Intensive Care for is transferred to Intensive Care for postoperative carepostoperative care

How long should the MgSO4 infusion continue

What are the problems that may arise from intensive care

Not less than 24 hours after delivery

Separation of mother and infant interferes with bonding and lactation.

Insomnia and stress to Carol and her relatives.

May increase the risk of thromboembolism

The baby weighs 1800g and has signs of IUGR.The baby weighs 1800g and has signs of IUGR.

What is the most common neonatal problem for this baby

How is it avoided

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 The baby does well. Carol’s BP still requires treatment postpartum.treatment postpartum.

When would expect recovery of renal or hepatic dysfunction

How about the hypertension

What drugs are used in the control of hypertension

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 Carol’s BP is normal off all medication by 6 weeks. Tests for autoimmune disease and weeks. Tests for autoimmune disease and thrombophilia are negativethrombophilia are negative

What is the risk that she will develop preeclampsia in a subsequent pregnancy

How could that risk be reduced

Is Carol at risk of hypertension in the future

50 – 66%

Low dose aspirin (100 mg daily preferably commencing in the 1st trimester) reduces risk by >17%

Also use Ca supplements 1.5G/day

YES

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