Hypertension in PregnancyHypertension in Pregnancyfor Undergraduatesfor Undergraduates
Max Brinsmead MB BS PhDMax Brinsmead MB BS PhD
February 2015February 2015
This talkThis talk How to measure BPHow to measure BP When is a pregnant woman hypertensiveWhen is a pregnant woman hypertensive What is the Differential DiagnosisWhat is the Differential Diagnosis What tests are required and how do you What tests are required and how do you
interpret theminterpret them Risk factors for pre-eclampsiaRisk factors for pre-eclampsia Pathophysiology of pre eclampsiaPathophysiology of pre eclampsia How to manage the hypertensive gravidaHow to manage the hypertensive gravida Drugs to lower BP in pregnancyDrugs to lower BP in pregnancy
This talk(2)This talk(2)
When to deliverWhen to deliver Best practice intrapartum careBest practice intrapartum care Who requires an anticonvulsant?Who requires an anticonvulsant? What is the best drug for Eclampsia?What is the best drug for Eclampsia? Best practice postpartum careBest practice postpartum care Prognosis after pre-eclampsiaPrognosis after pre-eclampsia Can pre-eclampsia be prevented?Can pre-eclampsia be prevented?
How to Measure BP in a Pregnant WomanHow to Measure BP in a Pregnant Woman
o Automated machines not recommendedAutomated machines not recommendedo Unless calibrated against a mercury sphygmomanometer in Unless calibrated against a mercury sphygmomanometer in
the individual patientthe individual patient
Appropriate sized cuffAppropriate sized cuff Seated for 2 - 3 minutes with feet supportedSeated for 2 - 3 minutes with feet supported Both arms first visitBoth arms first visit Palpate systolic and go 20 mm higherPalpate systolic and go 20 mm higher Deflate slowly 2 mm every secDeflate slowly 2 mm every sec Use Korotkoff 5 (or 4 if 5 absent) for diastolicUse Korotkoff 5 (or 4 if 5 absent) for diastolic Repeated measures may be requiredRepeated measures may be required Ambulatory monitoring useful for White Coat Ambulatory monitoring useful for White Coat
HypertensionHypertension
When is a Pregnant Woman When is a Pregnant Woman Hypertensive?Hypertensive?
>140/90 on >one occasion>140/90 on >one occasion (Rise of >30 systolic or >15 diastolic)(Rise of >30 systolic or >15 diastolic)
Knowledge of prior BP very importantKnowledge of prior BP very important No longer accepted as a diagnostic pointNo longer accepted as a diagnostic point
Severe hypertension is >169 systolic Severe hypertension is >169 systolic and and oror diastolic >109 diastolic >109
Requires admission and urgent RxRequires admission and urgent Rx
(However, the diagnosis is more important (However, the diagnosis is more important than the actual level of BP).than the actual level of BP).
Differential Diagnosis of Hypertension Differential Diagnosis of Hypertension in Pregnancyin Pregnancy
Gestational HypertensionGestational Hypertension Sustained hypertension after 20w of pregnancy without any Sustained hypertension after 20w of pregnancy without any
other organ involvement. Returns to normal in 3mother organ involvement. Returns to normal in 3m
PreeclampsiaPreeclampsia Sustained hypertension after 20w of pregnancy with Sustained hypertension after 20w of pregnancy with
evidence of other organ involvement. Returns to normal in evidence of other organ involvement. Returns to normal in 3m3m
Chronic HypertensionChronic Hypertension Hypertensive before 20w. 95% is Essential Hypertension Hypertensive before 20w. 95% is Essential Hypertension
Includes “White Coat Hypertension”Includes “White Coat Hypertension”
Systems involved in PreeclampsiaSystems involved in Preeclampsia RenalRenal
Significant proteinuria Significant proteinuria S Creat >90 S Creat >90 OliguriaOliguria
HepaticHepatic Elevated transaminases Elevated transaminases Epigastric or RUQ painEpigastric or RUQ pain
HaematologicalHaematological Thrombocytopenia Thrombocytopenia HaemolysisHaemolysis DICDIC
CNSCNS Eclampsia or strokeEclampsia or stroke Hyperreflexia with sustained clonusHyperreflexia with sustained clonus Severe headache or visual disturbanceSevere headache or visual disturbance
CardiovascularCardiovascular Pulmonary oedemaPulmonary oedema
PlacentalPlacental IUGRIUGR AbruptionAbruption
Please notePlease note
I have not used the words “Pregnancy induced I have not used the words “Pregnancy induced Hypertension” or PIHHypertension” or PIH
No mention is made of oedemaNo mention is made of oedema
Proteinuria is the most common manifestation of Proteinuria is the most common manifestation of “other system involvement” “other system involvement”
Evidence for other organ involvement in Pre Evidence for other organ involvement in Pre eclampsia is a mix of symptoms, signs and testseclampsia is a mix of symptoms, signs and tests
Some rare causes of preeclampsia Some rare causes of preeclampsia before 20w before 20w
Hydatidiform moleHydatidiform mole
Fetal triploidy (with or without partial mole)Fetal triploidy (with or without partial mole)
Severe renal diseaseSevere renal disease
Lupus obstetric syndromeLupus obstetric syndrome
Renal Disease in PregnancyRenal Disease in Pregnancy
Responsible for about 5% of chronic hypertensionResponsible for about 5% of chronic hypertension
Causes include:Causes include: chronic or recurrent infectionchronic or recurrent infection glomerulonephritisglomerulonephritis renal artery stenosisrenal artery stenosis
Must be assessed by creatinine clearance (CC) Must be assessed by creatinine clearance (CC) which doubles in normal pregnancywhich doubles in normal pregnancy
When CC falls below 50% the prognosis for a When CC falls below 50% the prognosis for a pregnancy is very badpregnancy is very bad
Monitoring for superimposed pre eclampsia can Monitoring for superimposed pre eclampsia can be difficult if there is chronic proteinuriabe difficult if there is chronic proteinuria
Some rare causes of hypertensionSome rare causes of hypertension
Coarctation of the aortaCoarctation of the aortaSometimes the clue is to measure BP in both armsSometimes the clue is to measure BP in both armsThere is a systolic murmur that can be heard in the There is a systolic murmur that can be heard in the
backback
PhaeochromocytomaPhaeochromocytomaParoxysms of symptomatic hypertensionParoxysms of symptomatic hypertensionThe clue to diagnosis is to think of itThe clue to diagnosis is to think of itAssociated with high levels of catecholaminesAssociated with high levels of catecholamines
HyperaldosteronismHyperaldosteronismAlso known as Conn’s diseaseAlso known as Conn’s disease
Placental tissuePlacental tissueIn healthy pregnancies cytotrophoblast In healthy pregnancies cytotrophoblast
infiltrates the decidual portion of the uterine infiltrates the decidual portion of the uterine spiral arteriesspiral arteries
In order to increase maternal blood flow to the In order to increase maternal blood flow to the placentaplacenta
In patients destined to develop pre eclampsia In patients destined to develop pre eclampsia this fails to occurthis fails to occur
This results in placental hypoperfusionThis results in placental hypoperfusionThese changes occur at <16 weeks gestation These changes occur at <16 weeks gestation
but the pre eclampsia may not be manifest until but the pre eclampsia may not be manifest until much later in the pregnancymuch later in the pregnancy
Pathophysiology of Pre eclampsiaPathophysiology of Pre eclampsia
HypoperfusionHypoperfusion of the Placenta of the Placenta Becomes worse as pregnancy progresses Becomes worse as pregnancy progresses The abnormal uterine vasculature is unable to The abnormal uterine vasculature is unable to
accommodate the normal rise in blood flow to accommodate the normal rise in blood flow to the fetus/placenta that occurs with increasing the fetus/placenta that occurs with increasing gestational age. gestational age.
Late placental changes consistent with Late placental changes consistent with ischemia include atherosis (lipid-laden cells in ischemia include atherosis (lipid-laden cells in the wall arterioles), fibrinoid necrosis, the wall arterioles), fibrinoid necrosis, thrombosis, sclerotic narrowing of arterioles, thrombosis, sclerotic narrowing of arterioles, and placental infarction and placental infarction
Pathophysiology of Pre eclampsiaPathophysiology of Pre eclampsia
An ‘immunolgical’ response to pregnancyAn ‘immunolgical’ response to pregnancy ---in ‘at risk’ or predisposed women---in ‘at risk’ or predisposed women
A response to a conceptus whose genetic A response to a conceptus whose genetic material is 50% foreign (from the father)material is 50% foreign (from the father)
A failure of ‘Blocking Antibody’A failure of ‘Blocking Antibody’
This disease is still a mysteryThis disease is still a mystery
Pathophysiology WHY?Pathophysiology WHY?
Contracted intravascular volume of motherContracted intravascular volume of motherIn reality a failure to increase plasma volumeIn reality a failure to increase plasma volume
↑↑Sensitivity to pressure agentsSensitivity to pressure agentsLeaky capillariesLeaky capillariesReduced oncotic pressureReduced oncotic pressure
In part due to low serum albumenIn part due to low serum albumen
Poor placental reservePoor placental reserveA fetus at risk of hypoxia and deathA fetus at risk of hypoxia and death
Pathophysiology WHAT?Pathophysiology WHAT?
Tests for the Hypertensive GravidaTests for the Hypertensive Gravida Blood testsBlood tests
FBC - look at HB, Haematocrit and PlateletsFBC - look at HB, Haematocrit and Platelets UEC - look at Creatinine Should be < 0.07 (or 70)UEC - look at Creatinine Should be < 0.07 (or 70) URATE - equivalent to weeks of gestationURATE - equivalent to weeks of gestation Liver enzymes – AST & ALT should be <70. Ignore ALPLiver enzymes – AST & ALT should be <70. Ignore ALP
UUrine Tests rine Tests UMCS - exclude UTI and look for castsUMCS - exclude UTI and look for casts Protein:Creatinine ratio from spot test (>30 significant)Protein:Creatinine ratio from spot test (>30 significant) 24 hr protein excretion (>300 mg/day significant)24 hr protein excretion (>300 mg/day significant)
Assess fetal welfare by CTG & Scan for Assess fetal welfare by CTG & Scan for amniotic fluid volume & umbilical artery amniotic fluid volume & umbilical artery DopplersDopplers
Management of Hypertensive Management of Hypertensive GravidaGravida
Hospitalise if pre-eclampticHospitalise if pre-eclamptic Discharge if “just BP”Discharge if “just BP” Bed rest only when there is proteinuriaBed rest only when there is proteinuria Control BP to protect mother from severe Control BP to protect mother from severe
hypertensionhypertension Role of antihypertensive agents for mild & Role of antihypertensive agents for mild &
moderate chronic hypertension is still moderate chronic hypertension is still controversialcontroversial
Delivery will cure pre eclampsia and Delivery will cure pre eclampsia and gestational hypertensiongestational hypertension
Remember thromboprophylaxisRemember thromboprophylaxis
Drugs for Hypertension in Drugs for Hypertension in Pregnancy?Pregnancy?
AldometAldomet An old and safe drug An old and safe drug
Beta BlockersBeta Blockers Labetalol widely used in AustraliaLabetalol widely used in Australia Oxyprenalol also shown in RCT to be usefulOxyprenalol also shown in RCT to be useful
Ca channel blockersCa channel blockersNifedipineNifedipine
PrazosinPrazosin Relaxes pressor arteriolesRelaxes pressor arterioles
Drugs for Hypertension in Drugs for Hypertension in Pregnancy?Pregnancy?
Combination therapy of drugs from Combination therapy of drugs from different classes is possible e.g.different classes is possible e.g.Aldomet + Beta blocker + PrazosinAldomet + Beta blocker + Prazosin
Do not use…Do not use…Thiazide diuretics – reduce plasma volumeThiazide diuretics – reduce plasma volumeHighly selective beta blokers – cause IUGRHighly selective beta blokers – cause IUGRACE inhibitors – may cause IUFDACE inhibitors – may cause IUFD
Aim for BP 130 -150 systolic and 80 – Aim for BP 130 -150 systolic and 80 – 100 diastolic100 diastolic
Drugs for Acute Hypertension in Drugs for Acute Hypertension in PregnancyPregnancy
IV IV HydralazineHydralazine IV IV LabetalolLabetalol
Not available in AustraliaNot available in Australia NifedipineNifedipine tablets crushed and oral tablets crushed and oral
Repeat after 30 minRepeat after 30 min IV IV DiazoxideDiazoxide in small boluses in small boluses
Which Drug is Best for Eclampsia?Which Drug is Best for Eclampsia?
First aid is more important than drugsFirst aid is more important than drugs Protect from injuryProtect from injury Secure an airwaySecure an airway Administer oxygenAdminister oxygen Then secure IV accessThen secure IV access
IV MgSOIV MgSO4 loading dose Maintain by infusion IV Diazepam only for status eclampticus Monitor urine output, respirations, O2
saturation and deep tendon jerks
Who Requires Delivery?Who Requires Delivery?
Pre eclampsia >36 completed weeksPre eclampsia >36 completed weeks Uncontrollable hypertensionUncontrollable hypertension Deteriorating renal, hepatic or haematologic Deteriorating renal, hepatic or haematologic
statestate Eclampsia or imminently eclampticEclampsia or imminently eclamptic Fetus is compromisedFetus is compromised
Give steroids to mature the fetal lungsGive steroids to mature the fetal lungs APH - abruptionAPH - abruption
How to DeliverHow to Deliver
Deliver vaginally if >37w and Cx is favourable Deliver vaginally if >37w and Cx is favourable or can be ripenedor can be ripened
Caesarean only if the above not metCaesarean only if the above not met Elective CS usually at gestations <35wElective CS usually at gestations <35w Inappropriate attempts at delivery when it is Inappropriate attempts at delivery when it is
not indicated is an invitation to CS (and more not indicated is an invitation to CS (and more CS) CS)
Deliver in an environment that can cope with Deliver in an environment that can cope with a severe multisystem diseasea severe multisystem disease
Don’t overlook patient’s and family’s psychological needsDon’t overlook patient’s and family’s psychological needs
Intrapartum CareIntrapartum Care
Assess convulsive risk and consider Assess convulsive risk and consider prophylactic MgSOprophylactic MgSO4
Control BP with an epidural or IV HydralazineControl BP with an epidural or IV Hydralazine Careful fluid balanceCareful fluid balance Monitor the fetusMonitor the fetus Avoid ergometrineAvoid ergometrine
Postpartum CarePostpartum Care Things may get worse before they get Things may get worse before they get
betterbetter Oliguria for 24 hours is commonOliguria for 24 hours is common
Seizure risk is greatest for 48 hrsSeizure risk is greatest for 48 hrs Continue MgSOContinue MgSO4 infusion for 24 hrs infusion for 24 hrs
Avoid NSAIDsAvoid NSAIDs Treat any BP >150/100Treat any BP >150/100 OK to discharge 3 days after BP OK to discharge 3 days after BP
controlcontrol Follow up weekly to 6w then 3mFollow up weekly to 6w then 3m
The Prognosis after Pre eclampsiaThe Prognosis after Pre eclampsia
Mild pre eclampsia near term has a low Mild pre eclampsia near term has a low recurrence riskrecurrence risk
Unless there is a new partner or a long gap to the next Unless there is a new partner or a long gap to the next pregnancypregnancy
Severe pre eclampsia prior to 34w has a 50- Severe pre eclampsia prior to 34w has a 50- 66% recurrence risk66% recurrence risk
Most recover by 12w but these patients are at Most recover by 12w but these patients are at increased lifetime risk of hypertension and increased lifetime risk of hypertension and related diseaserelated disease
Risk factors for severe pre eclampsiaRisk factors for severe pre eclampsia
Previous pre eclampsia at <35wPrevious pre eclampsia at <35w Renal diseaseRenal disease ThombophiliasThombophilias Autoimmune disease e.g. SLEAutoimmune disease e.g. SLE DiabetesDiabetes Multiple pregnancyMultiple pregnancy Severe alloimmunisationSevere alloimmunisation Family history of pre eclampsiaFamily history of pre eclampsia ObesityObesity Increasing maternal ageIncreasing maternal age
The prevention of pre eclampsiaThe prevention of pre eclampsiawith low dose Aspirinwith low dose Aspirin
History of fetal death or severe IUGRHistory of fetal death or severe IUGRPatients who required delivery for pre Patients who required delivery for pre
eclampsia prior to 34weclampsia prior to 34w You need to treat 4-5 to prevent one FDIU or You need to treat 4-5 to prevent one FDIU or
severe IUGRsevere IUGRDoes Does notnot increase the risk of APH or PPH increase the risk of APH or PPH
Conditions with high risk of pre eclampsia Conditions with high risk of pre eclampsia eg Lupus or homozygous for thrombophiliaeg Lupus or homozygous for thrombophilia
These patients also require heparinThese patients also require heparin
Also give Ca supplements 1.5 G/dayAlso give Ca supplements 1.5 G/day
For the NICE Guideline go For the NICE Guideline go toto
http://pathways.nice.org.uk/pathways/http://pathways.nice.org.uk/pathways/hypertension-in-pregnancyhypertension-in-pregnancy
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