Hypertension in pregnancy

1. HYPERTENSION IN PREGNANCY
Lindelani Malinda
Micah Maharaj
Resource Day: 30-01-2020

2. Objectives
Introduction
Classification and definition of hypertension in pregnancy
Investigations
Complications
Management
Eclampsia
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3. Introduction
◦ Complicates up to 10% of pregnancies
◦ Represents significant Maternal and Perinatal morbidity and Mortality
◦ Hypertensive disorders of pregnancy is an umbrella term encompassing
preexisting , gestational hypertension ,preeclampsia and it complications
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4. 4
Definition
Hypertension is defined as -:
◦ Blood pressure of >/= 140/90 mmHg
◦ Increase in systolic of 30mmHg
◦ Increase in Diastolic 15mmHg

5. Classification and definition of hypertension in
pregnancy
A. Gestational hypertension
B. Pre-eclampsia
C. Chronic hypertension
D. Chronic hypertension with superimposed pre-eclampsia
E. White coat Hypertension
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6. A. Gestational hypertension
Hypertension after 20 weeks gestation on two or more
occasions 4 hours apart without proteinuria on a previously
normotensive patient and resolves within 6 weeks post
delivery
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7. B. Chronic hypertension
Essential:
Blood pressure greater than 140/90 mmHg preconception or prior to 20
weeks without an underlying cause
Secondary Hypertension :
chronic kidney disease
endocrine disorders
coarctation of the aorta
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8. C. Chronic hypertension with superimposed
pre-eclampsia
The new development after 20 weeks gestation of one or
more of the features of pre-eclampsia in a patient with
preexisting chronic hypertension
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9. D. Pre-eclampsia
New onset Hypertension that arises after 20 weeks of gestation and returning
to normal within 6 weeks post partum ,and is associated with proteinuria.
Further classified
1. Pre eclampsia with Severe Features
2. Imminent Eclampsia
3. Eclampsia
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10. Risk factors of Hypertension In
Pregnancy
◦ Maternal
◦ Primigravida
◦ Family history of pregnancy induced hypertension
◦ DM, Chronic HPT, Renal insufficiency
◦ Anti-phospholipid syndrome and inherited thrombophilia
◦ Extremes of maternal age (18< or >35)
◦ Vascular or connective tissue disease
◦ High BMI
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11. 11
Fetal
◦ Multiple gestation
◦ Unexplained fetal growth restriction
◦ Previous unexplained stillbirths
◦ Hydrops fetalis
Paternal
Primi paternity
Male Partner whose previous partner had preeclampsia

12. 12
Socio economic
◦ Low socio economic status
◦ Recreational drug use
◦ Smoking
◦ Alcohol
◦ Stress

13. PRE-ECLAMPSIA
PATHOPHYSIOLOGY
• Immune factors , genetic factors , dietary factors, CKD , unknown
factors
• Trophoblastic maladaptation
• Reduced uteroplacental perfusion
• Cellular anoxia
• Release of angiogenic factors, apoptotic cells and trophoblastic debris
• Vascular endothelial damage
• Organ system involvement
• Clinical signs and then ^BP, proteinuria and IUGR
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14. 14
Complications
◦ Maternal
Renal failure
Cardiac failure
Liver failure
Eclampsia
pulmonary edema
Abruptio placentae
Stroke
HELLP Syndrome
Thrombocytopenia
◦ Fetal
Placental Insufficiency
Placental infarctions
IUGR
Fetal distress
Fetal death

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Chronic
hypertensio
n
Pre-
eclampsia
Superimposed pre-
eclampsia
age Usually > 30
years
Young or > 35
years
Usually >30 years
gravidity multigravida primigravida multigravida
Order of signs Fall pregnant
while
hypertensive
Weight gain
HPT
Oedema
proteinuria
Already hypertensive.
Develops severe HPT and
proteinuria
Eclampsia
Risk:maternal and fetal Low to mild Mild to high high
Risk of recurring in
subsequent pregnancies
high Small high
Renal function Relatively
unaffected
Early increase
in
urea,creatinine
,urates
Incr urea and creatinine but
urate can rise
disproportioally d/t pre-
eclmpsia
DIFFERENCES BETWEEN THESE DISORDERS

16. Principles in management of pre-
eclampsia
Admit to hospital :
Establish aetiology of hypertension
• To plan treatment
• To evaluate prognosis
History-taking:
• Previous history of hypertension
• Family History of Hypertension
Evidence of other organ involvement
• Cardiac
• Renal
Continuing Assessment
• 4-hourly BP recording
• Maternal investigations
• Foetal surveillance
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17. Principles in management of pre-
eclampsia
Control BP
 prevent eclampsia
Check and correct complications
Assess fetal compartment
Definite management is delivery
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18. Investigations
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Mother Fetus
Blood :
Hb Gestational age
Platelets Fetal activity (kick count)
Urea, creatinine, uric acid Non-stress test
24-hr proteinuria Ultrasound
•Biometry
•Amniotic Fluid volume
•Doppler
If thrombocytopenia present :
peripheral blood smear
Coagulation: ptt
LFT:ALT, AST& LDH
optional
ECG, Echo ,chest x-ray

19. Investigations
Urine dipstick:
1+ is eqv. to ± 300mg proteinuria
2+ is eqv. to ± 1000mg protein=> nephrotic range
proteinuria
3+ is eqv. to ± 4000mg/dl
FBC: ↓platelets, Hb
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20. Management of pre-eclampsia
Management is done according to clinical group:
Patients before with Severe early onset PET 24 weeks gestation: TOP is advised
Between 24 and 34 weeks: Room for conservative management if both Maternal and
Fetal Compartments are stable
After 34 weeks: Delivery
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21. Prevention of Pre-eclampsia
◦ LOW DOSE ASPIRIN (1mg/kg/daily)
◦ Indications include:
◦ History of early-onset pre-eclampsia
◦ Collagen Vascular Disease
◦ Recurrent pre-eclampsia in previous pregnancies
◦ Previous hypertension with perinatal mortality
◦ Recurrent foetal growth impairment of unknown aetiology
◦ Calcium (100-1500g/daily) is also used in the prevention of pre –eclampsia.
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22. Management of Pre-
eclampsia
◦ AIM of management is to maximise good perinatal outcomes without
endangering maternal health.
◦ ANTIHYPERTENSIVE TREATMENT.
◦ ASSESSING FOR COMPLICATIONS
◦ FETAL MONITORING
◦ USE OF MAGNESIUM SULPHATE
◦ TIMING AND MODE OF DELIVERY
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23. CONTROL OF BLOOD PRESSURE
DRUGS SUITABLE IN PREGNANCY
◦ Alpha-receptor antagonists: Methyldopa
Loading dose: 1-2 g po
Continuation: 500mg 3 times daily to maximum of 2g daily
◦ Alpha and beta-receptor antagonists: Labetalol
Can be used as a short acting agent
◦ Calcium channel blockers: Nifedipine
Long acting used both ante and post partum
Or short acting agent: 10 mg oral
◦ Arteriolar Vasodilators: Hydralazine
Adjunct to methyldopa
Can be used as a rapid agent
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24. 24
Cont…
◦ If BP is >140/90, commence treatment with Aldomet (Methyldopa) at
a dose of 500mg 6 hourly or 8 hourly depending on BP. Should the
BP be poorly controlled on Aldomet ie. 2 BP spikes in 24 hours
requiring use of a rapid-acting agent, add a second agent.
◦ Adalat (Nifedipine) starting at 10mg 8 hourly up to a maximum of
20mg 6-hourly
◦ Hydralazine is the third-line agent and can be started at a dose of 1mg
8 hourly up to a maximum of 7mg 8 hourly.

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Cont.….
◦ BP > 170/110 - should be treated as a hypertensive emergency
◦ Start a Labetalol infusion: 200mg in 200mls normal saline at 20/40/80 ml.hr
titrated against the BP every 30 minutes. Caution in patients with tachycardia.
◦ Alternatively administer Nifedipine capsules 10 mg orally immediately, and if
necessary 20-30 minutes later. Avoid sublingual Nifedipine.
◦ The goal should be to lower BP to 140/90 – 150/90.

26. Cont..
◦ Goal: Maintenance of maternal well-being and
delivery of infant who will survive and develop
normally.
◦ Thus, delivery is delayed
◦ Unless deterioration in the maternal or foetal condition
becomes a dominant feature.
◦ Betamethasone 12mg 12-hourly (two doses) to stimulate
foetal maturity for pregnancies less than 34 weeks
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27. IMMINENT ECLAMPSIA
◦ Symptoms
◦ Severe headache, not responding to simple analgesics
◦ Visual disturbances
◦ Nausea & Vomiting
◦ Epigastric pain
◦ Signs
◦ Increased knee jerks (hyperreflexia)
◦ Clonus
◦ Retinal spasm
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28. IMMINENT ECLAMPSIA-
TREATMENT
◦ 1. Definitive management is Delivery
◦ Lower blood pressure
◦ Maintenance of MGSO4
◦ Check complication
◦ Assess Fetal compartment
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29. ECLAMPSIA
◦ DEFINITION: CONVULSIONS associated
with hypertension and proteinuria in
pregnancy to up 6weeks postpartum .
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30. ECLAMPSIA-MANAGEMENT
◦ Check circulation, airways and breathing
◦ Place the patient in the left lateral position
◦ Administer oxygen – 6 to 8L / per minute
◦ Give Magnesium Sulphate for treatment and prevention of further
seizures
◦ Reduce blood pressure as per regimen
◦ Investigate for complications
◦ Definitive management is delivery
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Continuation
Neuro protection for at least 24 hours if:
◦ Poor arterial blood gases
◦ Unconscious/ GCS <8/15
◦ Extreme restlessness
◦ Laryngeal Oedema
◦ Aspiration

32. MAGNESIUM SULFATE
◦ MgSO4 used to control convulsions and prevent further convulsions.
◦ SIBAI’S INTRAVENOUS REGIMEN
Loading dose: 6g in 200ml over 20mins IV
Maintenance: 2g/hour IV
Continued until 24 hours post-delivery.
◦ PRITCHARD’S INTRAMUSCULAR REGIMEN
Loading dose:14g (4g IV over 5 mins and 10g IM, 5g in each buttock)
Maintenance: 5g 4-hourly IM.
This is used in primary care .
◦ ZUSPAN REGIMEN
Loading dose: 4g in 200ml IV over 15-20 minutes
Maintenance : 1 g hourly given by infusion pump 32

33. MAGNESIUM SULFATE
◦ Indications
 severe pre-eclampsia
 Imminent eclampsia
 eclampsia
Toxicity Manifests with:
 Loss of patellar reflexes
 Weakness; Drowsiness
 Nausea
 Muscle paralysis
 Respiratory Depression
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Monitoring
◦ Check the following signs every 4 hours before commencing the
next dose of magnesium sulphate.
◦ Presence of peripheral knee or arm reflexes
◦ Respiratory rate above 16 per minute
◦ Urine output of more than 30 mls per hour
◦ Monitor
◦ Blood pressure recording every 10-20 minutes.
◦ ½ Hourly pulse and urine output.
◦ Pulse oximeter if available

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Magnesium Sulphate Levels
◦ Normal range 0.7 – 1.0mmol/L
◦ Therapeutic Level 1.25 – 3.25 mmol/L
◦ Reflexes disappear 4-5 mmol/L
◦ Respiratory depression 6-8 mmol/L
◦ Cardiac Arrest > 15m.mol/L

36. MAGNESIUM SULFATE-
TOXICITY
◦ TO REVERSE MG TOXICITY: RULE OF 10
◦ Calcium Gluconate 10% at a dosage of 10 ml slowly intravenously over 10
minutes
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