Post on 13-Apr-2017
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
020406080
100120140
0 15 40
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