Pre-eclampsia and Hypertensive Pre-eclampsia and Hypertensive DiseaseDiseaseTariq Shafi10th September 2009

Plan of PresentationPlan of Presentation1. Normal blood pressure changes in pregnancy2. Differential diagnosis3. Pre-existing hypertension4. Pregnancy-induced hypertension5. Pre-eclampsia6. Stepwise management of pre-eclampsia

1. Normal Blood Pressure Changes In PregnancyMeasured in semi-

recumbent position at 45o. Diastolic pressure recorded when sound disappears

Trimester 1-2: blood volume increases, but increased SVR due to progesterone causes drop in BP

Trimester 2-3: Cardiac output increases and RAAS activated, restoring BP

Blood pressure changes in pregnancy

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Gestation (weeks)Blood

pre

ssur

e (m

mHg)

Systolic BloodPressure

DiastolicBloodPressure

2. Differential Diagnosis2. Differential DiagnosisBlood pressure problems in pregnancy can be divided into

three groups:1. Chronic hypertension2. Pregnancy-induced hypertension3. Pre-eclampsia

3. Chronic Hypertension3. Chronic Hypertension Includes:1. Known hypertensives 2. Patients whose hypertension is diagnosed prior to 20

weeks’ gestation Increased risk of pre-eclampsia, intrauterine fetal growth

restriction, placental abruption and stillbirth Investigate to identify secondary hypertension, look for

coexistent disease and identify pre-eclampsiaUse Methyldopa or Labetalol

4. Pregnancy-Induced HypertensionPersistently raised blood pressure after week 20 in

previously normotensive womanNot associated with proteinuriaTypically resolves within 6 weeks of deliveryClinical sequelae and management: as Chronic

Hypertension

5. Pre-eclampsiaA multisystem disorder specific to pregnancy and the

puerperiumAssociated with hypertension and proteinuria in the

second half of pregnancyMay be associated with sudden-onset oedema Is a disease of the placentaAffects 6% of all pregnancies

PathologyBlood vessel endothelial cell damage, in association

with an exaggerated maternal inflammatory response leads to vasospasm, increased capillary permeability and clotting dysfunction

These can affect all the maternal organs to varying degrees

Pathology Manifestation

Vasospasm HypertensionIncreased permeability ProteinuriaReduced placental perfusion IUGRReduced cerebral perfusion Eclampsia

Course and degrees of pre-eclampsiaThe disease is progressive, but is variable and

unpredictableHypertension usually precedes proteinuria

Classification Description

Mild Proteinuria and hypertension <170/110mmHg

Moderate Proteinuria and hypertension ≥170/110mmHg

Severe Proteinuria and hypertension < 32 weeks or with maternal complicationse.g. HELLP, eclamptic fits

PathophysiologyStage 1 (Poor

placentation) Incomplete trophoblastic

invasion of spiral arterioles results in reduced uteroplacental blood flow

Stage 2 (Inflammation) The ischaemic placenta

induces widespread endothelial cell damage and maternal systemic inflammatory response

Diagnostic CriteriaMade after 20 weeks’ gestationNew-onset hypertension (sustained BP ≥ 140/90 in a

previously normotensive woman)New-onset significant proteinuria (>0.3g/24h or ≥1+ on

an MSU in the absence of a UTI)Sudden-onset oedema (of face, hands and legs) may also

be present

Clinical FeaturesHeadache

Visual disturbances

Vomiting

Drowsiness

Epigastric pain/tenderness

Oedema

Hypertension

Proteinuria

ComplicationsEclampsia

CVA

DIC

HELLP

Pulmonary oedema

Liver complications

IUGR

Placental abruption

Increased mortality/morbidity

Renal Failure

Pre-eclampsia: a placental disease

InvestigationsTo confirm the diagnosisDipstick urinalysis If positive, exclude UTI by MSUAssess protein:creatinine ratio (≥30g/nmol). If

significant, do 24h urine (≥0.3g/24h) To monitor maternal complicationsSerum urate (elevated)Platelets (reduced)LFTs (ALT/AST) (elevated)Serum urea and creatinine (elevated)To monitor fetal complicationsUltrasoundUmbilical artery Doppler

6. Stepwise Management of Pre-eclampsiaTreatment traditionally focused on treating eclampsiaHowever, pre-eclampsia is a mixture of diseases and

presentationsThe mainstay of management of pre-eclampsia is

appropriate antenatal care, with a low threshold for referral for intervention

Risk Assessment early in PregnancyBefore 20 weeks, offer women specialist input if one of:Previous pre-eclampsiaMultiple pregnancyPre-existing hypertension or booking DBP ≥ 90mmHgPre-existing renal disease or booking proteinuriaPre-existing diabetesPresence of antiphospholipid antibodiesOr any two of:First pregnancy or ≥ 10 years since last babyAge ≥ 40 yearsBMI ≥ 35Family history of pre-eclampsia (mother or sister)

After 20 weeks gestationAt 20 weeks, women should be assessed for the signs and

symptoms of pre-eclampsiaReferred to Maternity Assessment Suite if:

New hypertensionNew proteinuriaSymptoms of headache or visual disturbance, or bothEpigastric pain or vomiting, or bothReduced fetal movements, small for gestational age

infant

After 20 weeks gestation – MAS assessment If proteinuria only, repeat pre-eclampsia assessment in

community within 1 weekAdmit if any features in box belowOtherwise refer for hospital step-up assessment, to confirm

the presence of significant hypertension, distinguish pre-eclampsia from the differentials and determine follow-up

Diastolic ≥110 and ≥1+ protein on dipstickSystolic ≥170 and ≥1+ protein on dipstickDiastolic ≥90 and new proteinuria ≥1+ on dipstick with symptoms

Hospital Step-Up AssessmentAssessment includes blood pressure readings, urinalysis

for protein, monitoring of symptoms and foetal movements, fundal height and foetal monitoring for gestation

If SBP < 140 and DBP <90 and protein:creatinine ratio ≥ 30mg/mmol and symptoms/bloods abnormal, admit

If SBP 140-169 and DBP 90-109 and protein:creatinine ratio ≥ 30mg/mmol or symptoms or bloods abnormal, admit

Inpatient ManagementAssess blood pressure, urinalysisAssess signs (oedema, auscultate heart and lung fields,

epigastric tenderness, fundi for papilloedema, tendon reflexes and clonus)

Assess fetal size, presentation and well-being. Do CTG, U/S for biometry, umbilical artery Doppler, liquor volume, biophysical score

Do PET bloods, Group and Save or Cross-matchMonitor observations including fluid balance and urine

output

Management of blood pressureMandatory when systolic blood pressure ≥ 170mmHg

and diastolic blood pressure ≥ 110mmHgThe use of antihypertensives to treat mild to moderate

hypertension reduces the risk of severe hypertensionEarly treatment reduces neonatal complications e.g.

respiratory distress syndromeOral methyldopa or labetalol used for mild to moderate

hypertensionSustained, markedly elevated blood pressure treated by

IV labetalol

Management of complicationsEclampsiaMagnesium sulphate (IV or IM)Used as prevention if sustained SBP >160, DBP >110;

proteinuria > 1g/24h or ≥ 3+ on dipstick; liver and/or renal impairment; coagulopathy

IM route easier to administer IV route provides better blood levels

HELLP SyndromeActivation of coagulation cascade destroys red blood

cells, consumes platelets and causes periportal necrosis in liver

Causes headache, blurred vision, malaise, upper abdominal pain, paraesthesia

May cause liver rupture and seizure or coma

Timing of DeliveryPre-eclampsia is progressive and cured only by deliveryComplications likely within 2 weeks of proteinuria

Setting ActionMild hypertension, no fetal compromise

Monitor. Induce at term

Moderate or severe pre-eclampsia

After 34 weeks: delivery. Before 34 weeks: Steroids, treat hypertension and monitor. Delivery if mother/fetus deteriorates

Severe pre-eclampsia with complications

Delivery

Conduct of DeliveryThe ultimate cure for pre-eclampsia, but does not have

an immediate effectEpidural analgesia helps reduce the blood pressureAntihypertensives can be used during labourOxytocin used in third stage

Before 34 weeks

Caesarean section

After 34 weeks

Vaginal deliveryInduce with prostaglandins

Post-natal care of the pre-eclamptic patient It often takes at least 24h post delivery for severe

disease to improve and it may worsen during this time

Parameter Measurement

Blood investigations LFTs, platelets, renal function

Fluid balance Urine output

Blood pressure Monitor. Continued admission advisable until 5 days postpartum. Treat with beta blocker if raised

SummaryBlood pressure falls in early pregnancy, restored during the

third trimesterChronic hypertension and pregnancy-induced hypertension

associated with risks to mother and fetus.Pre-eclampsia is a placental disease and affects multiple

systems in the body. It resolves after pregnancyMain concern is eclampsia, HELLP, CVA, placental abruption

and pulmonary oedema in the mother; IUGR and stillbirth in the fetus

Blood pressure treated by antihypertensivesEclampsia treated by magnesium sulphateModerate or severe pre-eclampsia requires delivery; if

gestation less than 34 weeks, delay if possible. If complications or fetal distress, deliver regardless

Continue monitoring postpartum for blood investigations, fluid balance and blood pressure

References1. Impey L, Child C. Obstetrics and Gynaecology. 3rd

Ed. Oxford: Wiley-Blackwell; 2008. Chapter 202. Parisaei M, Shailendra A, Dutta R, Broadbent JAM.

Obstetrics and Gynaecology (Crash Course Series). 2nd Ed. Edinburgh: Elsevier; 2008. Chapter 35

3. Walker JJ. Stepwise Management. In: Lyall F, Belfort M, editors. Pre-eclampsia – Etiology and Clinical Practice. 2nd Ed. Cambridge: Cambridge University Press; 2008. Chapter 24

4. Nottingham University Hospitals NHS Trust Guidelines