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HYPERTENSION IN PREGNANCY
Neil Vanes, Obstetric and Gynaecology
UHCW
Scope of This Talk
• Pre-eclampsia• Eclampsia• Pregnancy-Induced (Gestational)
Hypertension• Essential Hypertension
PET/Eclampsia 3
Hypertensive disorders
N o p ro te in u ria -PIH
M ild an d m od era te P E T Severe PET Eclam psia HELLP
P ro te in u ria an d R a ised B PPre -eclam psia
Pregnancy induced hypertension(R a ised B P a fte r 2 0 w eeks )
Chronic hypertension(R a ised B P b e fo re 2 0 w eeks g es ta tion )
R a ised B P in p reg n an cy> o r = 1 4 0 /9 0
What you need to know.
• Definition and symptoms PET• Prevention of PET• Who is at risk of PET• History, examination and investigation of
patients with suspected PET• Management of PET (mild and severe)• Prevention of fits• When to deliver• Postnatal care
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 5
Pre-Eclampsia: Definition Hypertension and proteinuria with onset
≥20 weeks Oedema from classical definition dropped as not
discriminating clinically Onset <20 weeks ONLY seen in hydatidiform mole
(triploid pregnancy) –extremely rare
• Symptoms– NOT necessary to diagnose PET– Marker of more severe disease/progression
towards eclampsia
DEFINITIONS (2)• HYPERTENSION: Diastolic ≥90mmHg on 2
occasions 4-6 hours apart OR ≥110mmHg on one occasion
• PROTEINURIA : >300mg/24 hours• 24 hour collection or (preferably) PCR (>30)
• Differentiation from PIH/renal disease• Timing• Other findings eg blood in urine, abnormal U+E
Definitions of Hypertension in Pregnancy
MILD MODERATE SEVERE
Systolic 140-149 150-159 160
Diastolic 90-99 100-109 110
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 8
Incidence (some facts and figures)• 10% women have hypertension• 5% pregnancies have PET
• 1-2% pregnancies have severe PET
• Rates eclampsia 26.8/100 000 maternities (UKOSS reporting system 2003-5)
• Worldwide every year 1.5-8 million develop PET with 150 000 deaths
• UK: 18 deaths (2006-8)• 9 cerebral haemorrhage/infarction • 5 from hypoxic arrest after fit• 7 were eclamptic, 8 had HELLP syndrome
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 9
Importance
Maternal Risks◦ DEATH◦ Blindness◦ Neurological sequelae (haemorrhage/infarction)◦ Fits (Eclampsia)◦ Renal impairment/failure◦ Hepatic failure/rupture◦ Abruption◦ DIC
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 10
Importance
Fetal Risks Death◦ Abruption-> hypoxia◦ IUGR
◦ (onset PET <28 weeks->50% babies have IUGR)◦ Hypoxia◦ Prematurity (PET is cause of >40% iatrogenic
preterm dels) respiratory complications (RDS) neurodevelopmental complications (inc.learning
difficulty/IQ in up to 60%)
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 11
Risk Factors:-Pre-Eclampsia• Primiparous• First pregnancy with
new partner• Family history (1 in 3
risk if mother had PET)• Twins/multiples• Pregestational
Diabetes• Previous PET (if
severe/ <28 weeks, 50% recurrence)
• Essential hypertension
• Renal disease• SLE• Antiphospholipid
syndrome• Thrombophilias• Age >40• Obesity
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 12
Pathophysiology “The disease of theories”
Pregnancy specific syndrome Placenta has a central role to play
◦ Reduced placental perfusion◦ Inadequate vascular remodelling at ~16 wks◦ Relative hypoperfusion◦→Oxidative stress◦→Widespread endothelial dysfunction◦→Systemic disease
Spectrum of same underlying placental pathology
Usually coexist
PET and IUGR
PET IUGR
Aspirin: Who to Treat?HIGH RISK: women with
ANY of:• hypertensive disease
during a previous pregnancy
• chronic kidney disease• autoimmune disease
such as systemic lupus erythematosis or antiphospholipid syndrome
• type 1 or type 2 diabetes• chronic hypertension.
MODERATE RISK: women with >1 of:
• first pregnancy• age 40 years or older• pregnancy interval of
more than 10 years• body mass index (BMI)
of 35 kg/m² or more at first visit
• family history of pre-eclampsia
• multiple pregnancy.
NICE : Hypertension in Pregnancy (RCOG/RCM, August 2010)• Evidence supports use of aspirin in women
at ‘high’ or ‘moderate’ risk of developing PET
• Use of 75mg per day aspirin from 12 weeks to delivery• No evidence of fetal harm at this dose• No convincing evidence increased risk APH/PPH
Clinical diagnosis
Classic triad◦ Hypertension 140/90◦ Proteinuria >300mg in 24 hours (RCOG)◦ Oedema (least reliable)
◦ BUT....◦ Proteinuria and raised BP x 2 occasions 6 hrs
apart (or once if DBP ≥110 and heavy proteinuria >2+ (=1g/24h))
CLINICAL FEATURES
Mild hypertension
Mild proteinuria
>20 weeks pregnant
= Mild pre-eclampsia
DIAGNOSIS?
What questions should you ask?• Headache (classically severe)
– Effects hypertension• Visual disturbances (‘flashing lights’)
– Sign of cerebral vasospasm/impending eclampsia• Epigastric pain
– Hepatic congestion/liver capsule stretching• Is baby moving normally?
– Fetal wellbeing
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 19
PET-Maternal Investigations• BLOOD:• FBC- platelet count
– Platelets <100 indicate progressive/worsening disease
• U+E signs renal dysfunction (late)• Urate hyperuricaemia
– ( early, doesn’t predict outcomes well )
• LFTs elevated transaminases– Can indicate worsening of disease
• Clotting X (not routinely if plts>100)
• URINARY:• MSU to exclude UTI as cause of protein• PCR quantify proteinuria
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 20
PET
• Fetal assessment– Clinical– USS for growth– CTGs
• ?cervical assessment –vaginal examination• (depending on gestation)
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 21
Mild PET Classically asymptomatic BP 140/90 (ish)-mild hypertension Maybe trace-+ proteinuria Often incidental finding at CMW clinic
attendance
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 22
Monitoring MILD PET
• Monitor BP– CMW– Day assessment or Triage Unit (outpatient Mx)
• Monitor bloods– Weekly or twice weekly (depends on sitn)
• Monitor fetus– CTG– Serial USS
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 23
Definitive treatment
• Deliver when– BP/protein or clinical condition deteriorates so
become moderate or severe PET– Reaches 41 weeks and no change in condition– Fetal condition mandates delivery even if
maternal condition stable
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 24
Moderate PET Classically asymptomatic
◦ May have odd headache or occ visual disturbances
BP 150/100 (ish)-moderate hypertension Usually + - ++proteinuria Often incidental finding at CMW clinic
attendance◦ May present with headaches
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 25
Monitoring MODERATE PET
• Monitor BP– Admit initially-4 hourly BP– Consider antihypertensives if <36 weeks to
prolong pregnancy– If 36 weeks or greater ?delivery
• Monitor bloods– Check on admission– Check 2-3x weekly (if wish to prolong pregnancy)
• Monitor fetus– CTG– Serial USS (with LV/Dopplers)
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 26
Definitive treatment
• Deliver when– Reaches 36-37 weeks or diagnosis after this
gestation– Fetal condition mandates delivery even if
maternal condition stable and below this gestation
Severe pre-eclampsia SYSTOLIC 160-180+ DIASTOLIC >110
◦ =Severe hypertension
HEAVY PROTEINURIA
May present unwell or asymptomatic
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 27
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 28
Symptoms
• Headache (BP)• Flashing lights (lightning) (cerebral oedema)• Epigastric pain (stretching of liver capsule)• Oedema (albumin/BP)• Less common:
• blindness, scotoma, oliguria, SOB
• Asymptomatic
Signs: Severe PET
CNS◦ Disorientation/ irritability◦ Hyperreflexia◦ FITS◦ Clonus◦ Blindness◦ Scotoma◦ Papilloedema
– Hepatic◦ Abnormal LFTs/dysfunction◦ Epigastric pain/tenderness
Renal◦ Elevated creatnine,
urea, urate◦ Oliguria◦ Heavy proteinuria
>5g in 24 hrs Haemtological
◦ Thrombocytopaenia◦ Haemolysis
Pulmonary◦ Shortness of
breath
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 30
Management of severe pre-eclampsia• Immediate admission to hospital
• High dependency care/LW-QUIET– Invasive monitoring (arterial line +/- CVP)– NICU for baby if early gestation
• Senior multidisciplinary involvement early-obs and anaesthetics
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 31
Aims of treatment
Aims
1. Prevent seizures2. Control hypertension (to prevent cerebral
haemorrhage)3. Deliver safely (stabilise, +/- IUT, +/- steroids)
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 32
Maternal Assessment• BP- every 15 minutes [MEOWS]• Urine output-hourly• Urinary protein dipstix• Strict fluid balance chart
• Restrict 60-80ml/hr• Bloods
– U+E, urea, creatnine, urate– FBC esp. platelets (G+S)– LFTs
• Deep tendon reflexes and presence of clonus• CTG
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 33
Control blood pressure• Antihypertensives – aim for diastolic 80-99,
systolic <150
– IV hydralazine (5mg every 15 minutes to acutely control BP)
– IV labetolol (Not good if asthmatic or already signs of pulmonary oedema-first line in many places now)
– Oral nifedipine 10mg NOT SUBLINGUAL
– Methyldopa TOO SLOW ONSET (24-48 hours) for use in acute situation
– Titrate IV antihypertensive vs. BP then infusion
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 34
KEY POINTS: Hypertension
Systolic blood pressure of 160 mm/Hg or more = anti-hypertensive treatment.
(irrespective of diastolic)
Consideration starting treatment at lower pressures if the overall clinical picture suggests likely rapid deterioration with anticipation of severe hypertension.
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 35
Prevent Fits• Magnesium sulphate
– All severe and moderate PET (MAGPIE)– 4g IV over 15 minutes– Then infusion 1g/ hour
– Monitor reflexes (present) urine OP (>30ml/hr) and respiratory rate (>12/minute)– Slows neuromuscular conduction and decreases
CNS irritability– Best anticonvulsant in these circumstances
AND IN ECLAMPSIA– No effect on BP– Tell anaesthetist if GA as potentiates effects of
muscle relaxants
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 36
Magnesium toxicity
If urine OP OK then likely not to accumulate (85% renal excretion)
If urine output falls, reduce dose to 0.5g/hour
If signs toxicity, stop Antidote = Calcium
gluconate 1g IV over 3 minutes
Magnesium levels◦ Therapeutic 2-4 mmol/l◦ Warmth, flushing, slurred
speech 3.8-5mmol/l◦ Loss of patellar reflexes >5
mmol/l◦ Respiratory depression >6
mmol/l◦ Respiratory arrest 6.3-
7mmol/l◦ Cardiac arrest, asystole >12
mmol/l
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 37
MAGPIE
MgSO4 produced 58% reduced risk of eclampsia (0.8% cf. 1.9%)-across all categories of PET
Maternal mortality lower as well RR 0.55, CI 0.26-1.14
Lancet 2002; 359: 1877-90.
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 38
Deliver Baby If severe PET, should NOT transfer Ensure SCBU aware if baby premature Give antenatal steroids if time but usually,
if require IV therapy, delivery is indicated once stabilised
If cervix favourable and patient >36 weeks, consider short trial IOL
If cervix unfavourable and/or <36 weeks, deliver by LSCS
Anaesthesia regional vs. general
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 39
DELIVERY: Key Points ◦ Risk of sharp rise of BP on intubation
This may be obtunded by large dose alfentanyl or similar
Need experienced and senior anaesthetist to give GA in these circumstances
◦ Syntometrine should not be given for the active management of the third stage if the mother is hypertensive, or if her blood pressure has not been checked. (ergometrine causes vasospasm and a sharp rise in
BP which may precipitate hypertensive crisis, fits or cerebral haemorrhage)
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 40
ECLAMPSIA• Occurrence of fits
– 44% postpartum – 38% antenatal) – ALWAYS GRAND MAL
• Due usually to cerebral vasospasm
Occurrence of fits increases risks of maternal death x10
Seizures may precipitate hypoxic cardiac arrest and maternal death
Seizures = bad news
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 42
What isn’t eclampsia? Beware known epileptics
◦ If BP normal, no protein, typical for their type of fit-may be epilepsy BUT any fit must be considered as eclampsia until proven otherwise especially of BP slightly up etc
Any FOCAL fit is not eclampsia◦ Consider SOL eg cerebral bleed/infarction due
to severe PET◦ Arrange head CT urgently
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 43
Eclampsia• Treatment is IV magnesium sulphate-4g loading
• then continue infusion at 1g/hr• i.e the same as for severe PET
• If recurrent fits or fit already on MgSO4• then further 2g IV bolus/increase infusion to 1.5g/hr
• If fits persist• check magnesium levels, • contact anaesthetists, • consider CT, • consider intubation and ventilation
• If antenatal, stabilise and Deliver
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 44
Postnatal care Watch closely on HDU/LW
◦ ¼ hourly BP, SaO2, pulse, resps◦ Hourly reflexes, urine output, fluid restriction 60-
80ml/hr◦ One to one care
Anticipate possible worsening BP or seizures in first 18-24 hours
Hence MgSO4, may need antihypertensives de novo Continue MgSO4 for 24 hours and then review
Do not need to taper off MgSO4, just stop Do not feed within 12 hours as significant risk
ileus- sips H2O only until next morning then review for bowel sounds
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 45
Disease Progression
Often improve quickly Some may deteriorate further
immediately after delivery –may continue to worsen for 24 + hours◦ Worsening BP◦ Worsening bloods◦ Oliguria/anuria◦ Increased risk fits
Consult seniors and manage with multidisciplinary team
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 46
Postnatal Management-Hypertension Hypertension may persist for some weeks Switch to oral treatment when feasible
◦ Atenolol◦ Nifedipine
Polypharmacy may be required to control BP-consult with physicians
Ensure regular BP checks arranged on discharge with review and follow-up by GP◦ Good communication is the key◦ Check BP days 1, 2, 3-5 and 7◦ If still hypertensive at 6 weeks, refer physicians
PET/EclampsiaGeorge Eliot Hospital, Nuneaton 47
HELLP syndrome
• Haemolysis• Elevated• Liver Enzymes• Low• Platelets
• 1-12% PET (usually severe end of spectrum)
• Commoner in multips• Variable presentation
– RUQ pain, epigastric pain, nausea + vomiting
– 85% hypertensive at presentation
• Present: 2/3 antepartum, 1/3 postpartum– mid 2nd trimester to several
days postnatal
Next Pregnancy?
• If ‘straightforward’ PET– Risk PIH 13-53%– Risk PET 16%
• If severe PET, eclampsia or HELLP and birth <34 weeks– Risk PET 25%
• If severe PET/eclampsia/HELLP and delivery <28 weeks– Risk PET is 55%
Gestational (Pregnancy-Induced) Hypertension (PIH) Development of hypertension in pregnancy
after 20 weeks ↑Risks of progression to PET if diagnosed
<32 weeks Assess by:
◦ Clinical assessment◦ Dipstix for proteinuria (should be negative)◦ Check fetal wellbeing
Essential Hypertension Pre-existing raised blood pressure May be on treatment or just under
observation May be known prior to pregnancy or
detected at booking as raised BP
Risks to Mum Risks to Baby Worsening of BP Superimposed pre-
eclampsia Medical over-
intervention
Teratogenesis from certain drugs (eg ACEI)
IUGR Pre-eclampsia Hypoglycaemia if
on labetolol and breastfeeding
Pre-pregnancy If planned, review medications
◦ Take off teratogenic meds e.g. ACEI or similar◦ Take off diuretics (reduce plasma vol and fetal
perfusion) Optimise diet/ weight loss (if raised BMI) Stop smoking Start folic acid
Early pregnancy
Review meds at booking Take off any teratogenic meds Start folic acid Early booking at hospital for risk review Dating scan +/- NT (combined) scan Plan for pregnancy
◦ Including issues re: obesity, screening for GDM◦ Low dose aspirin from 12 weeks
Pregnancy Regular BP checks May need to come
off meds if BP ↓↓ May need to start or
restart meds later in pregnancy as BP rises
Growth scans (screen for IUGR)
Joint care between MW and hospital
Later Pregnancy If BP well controlled and fetal growth
normal, aim to labour spontaneously or induce as postdates
If BP raised, try control first with medications
If superimposed PET or fetal growth issues, consider delivering early
NO ERGOMETRINE at delivery-syntocinon only
Post delivery Watch BP for at least 24-48 hours May need oral antihypertensives Communicate closely with GP to ensure that
BP monitoring is taken over and ongoing care is handed over to GP
Summary
• Know definitions PIH, PET, essential HT• Differentiate between each• What questions to ask• What tests to do• Prevention of PET• Treatment of PET• Treatment of PIH• Treatment of essential HT in pregnancy
What is the definition of mild hypertension in pregnancy?
BP 140/90
What three symptoms do you specifically ask about in pre-eclampsia?
Headaches, visual disturbances, epigastric pain
Which of these is not a moderate risk factor for pre-eclampsia?◦ Twins◦ Diabetes◦ Maternal age >40
Quick Quiz (1)
TRUE or FALSE: Calcium has been shown to prevent PET in UK populations
FALSE Name a drug used to treat severe hypertension in
pregnancy/PET Labetolol, Hydralazine, Nifedipine What is the anticonvulsant of choice in PET? Magnesium sulphate
Which of these is not altered in HELLP syndrome?◦ Platelets◦ ALT◦ Alkaline phosphatase
Quick Quiz (2)
TRUE or FALSE? IUGR is present in >50% women with PET <28 weeks
TRUE TRUE OR FALSE? Lisinopril is teratogenic TRUE TRUE OR FALSE? Moderate PIH is an indication for
delivery <37 weeks FALSE TRUE OR FALSE? Women with severe PET and early
gestation should be transferred out to a tertiary unit ASAP
FALSE
Quick Quiz (3)
Magnesium overdose is not associated with which of the following?◦ Vomiting◦ Cardiac arrest◦ Muscle weakness
Which drug is the antidote to magnesium overdose?
Calcium gluconate Which blood tests should you do in pre-
eclampsia?
Quick Quiz (4)