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Explore the hemodynamic and biochemical changes in normal pregnancy, as well as the different types of hypertensive disorders that can occur during pregnancy. Learn how to manage these disorders and understand the potential complications they can pose.
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Hypertansive disorders in pregnancy Zehra Eren,M.D.
LEARNING OBJECTIVES • recall hemodynamic and biochemical changes in normal pregnancy • describe preeclampsia-eclampsia • describe chronic (preexiting ) hypertension • describe preeclampsia-eclampsia superimposed upon chronic hypertension • describe gestational hypertension • explain HEELP Syndrome • manage hypertensive disorders during pregnancy
Cardiovascular and Renal Physiology BloodPresure (BP) Regulation: • BP fallshortlyafterconceptionandreturnto normal at term - peripheralvasodilatationandresistancetoangiotensin II (prostacyclinandprolactinlevels↑) -Nitricoxidesynthesis↑ • Renin-angiotensin-aldosteronesystem(RAAS) is stimulated, aldosterone is critical in maintainingsodiumbalance
Volume Regulation • Circulatingbloodvolume↑ 50% • Redbloodcellmass↑20-30% • Cumulativesodiumretention (500-900mEq) → extrasellularfluidvolume↑ → weightgain → ‘’benign ‘’ edema of lowerextremities
Renal Hemodynamics • GFR: secondtrimester↑ 50% lasttrimester↑20% returntoprepartumlevelswithin 3 monts • Normal plasmacreatininefallto 0.5 mg/dl >0.8 mg/dl shoud be consideredabnormal • Renalbloodflow↑85% ↑cardiacoutput (30-40%max) ↑renalvasodilatation (afferentandefferent)
Hypertensive disorders • Systolic BP >140 mm Hg /125mmHg Diastolic BP >90 mm Hg /75mmHg • Mostcommon (10% of pregnancies) • ↑maternalandfetalmortalityandmorbidity • Leadingtoprematurebirth
Chronic Hypertention • HT presentbeforepregnancyordiagnosedbeforetwentiethweek of gestation • May include HT diagnosedduringpregnancythatdoes not resolveafterdelivery • May be associatedwithnephrosclerosiswith minimal proteinuria • İncreased risk of preeclampsia, abruptioplacentae, intrauteringrowthretardationandsecondtrimesterfetaldeath
Treatment • İn stage 1 and 2 HT, mayrequirelessorevenantihypertansivesif BP is controlled • Methyldopa is preferredagentfortreatment • İn womenwhoenterpregnancywithwell-controlled BP, sameregimen can be continued • ACE andARBsarecontraindicated
Gestational Hypertantion Essentials of Diagnosis • Maternal blood pressure elevation of ≥140 mm Hg systolic or ≥90 mm Hg diastolic on 2 occasions 6 hours apart in a previously normotensive woman ≥20 weeks' gestation • No evidence of proteinuria • Resolved after delivery ( women are at risk for chronic HT) • Risk factors: multiparity, obesity, positive family history
Preeclampsia-Eclampsia • Systemic syndrome unique to pregnancy • Essentials of Diagnosis • Maternal blood pressure elevation of ≥140 mm Hg systolic or ≥90 mm Hg diastolic on 2 occasions 6 hours apart • Proteinuria ≥300 mg in a 24-hour urine specimen • Resolving with delivery • Eclapsia: occurrence of sezures
Preeclampsia-Eclampsia Hypertension in pregnancy: Report of the American College of Obstetricians and Gynecologists' Task Force on Hypertension in Pregnancy. Obstet Gynecol 2013; 122:1122
Renal Abnormalities • Renalbloodflowand GFR fall • Decreasedurateclearenceandincreasedcalciumreabsorption→hyperuricemiaandhypocalciuria • GFR can decreaseby 30-40%→creatininelevelsincreased (1.0-1.5mg/dL) • Hyperuricemiamaycorrelatewithclinicalseverity of preeclampsia (>4.5mg/dL)
Clinical features • Usuallybeginsafterthethirty-secondweekandmayseenpostpartumwithin 24-48 h afterdelivery • Usuallyresolveswithin 10 daysafterdelivery • Diastolic HT is prominent, with SP<160mmHg • SBP>200mmHg suggestpreeclampsiasuperimposed on chronic HT • When HT andproteinuriaoccurbefore 20 w, etiologiesotherthanpreeclampsiashould be sought
Clinical features • Pulmonaryedemacan occurduetochanges in pulmonarycapillarypermeability • Hyperreflexiasecondarytocentralnervoussystemexcitabilityreflects of neurologicinvolvement
Severe preeclampsia 2013 criteria do not include -proteinuria >5 grams/24 hours and -fetal growth restriction as features of severe disease Hypertension in pregnancy: Report of the American College of Obstetricians and Gynecologists' Task Force on Hypertension in Pregnancy. Obstet Gynecol 2013; 122:1122
HEELP Syndrome • HEmolysis • ElevatedLiverFunctionTests • LowPlatelets
HEELP Syndrome • Commonlyassociatedwith severe HT andvariabledegrees of renalfailure • May be associatedwith -pulmonaryedema -ascites -acuterenalfailure -disseminatedintravascularcoagulation
Treatment of Preeclampsia • Prophylacticlow-doze aspirin orcalcium→ noevidence of significantreductionorimprovedoutcomes • Bed rest→ therapy of choiceformilddisease (BP<140/90 mmHg, proteinuria<500mg/24h, normal renalfonction,uratelevels<4.5mg, normal PLT, andnoevidence of hemolysisorhepaticdysfunction) • Optimal levels has not be defined
Preeclampsia superimposed upon chronic hypertension • Difficulttodistinguishfromworseninghypertansion • Suspect in womenwith HT before 20 week of gestationwhodeveloptproteinuriaorsuddenincrease in BP • Morelikelytooccur in olderpatients • Hyperuricemia, proteiuria, orrise in serum creatininesuggestspreeclampsia • Risk in womenwithsome form of renaldisease is between 20-40%
Acute Renal Failure in Pregnancy • Earlypregnancy 1.Prerenalazotemia→ hyperemesis, hemorrage of spontaneusabortion 2. Acutetubularnecrosis→ volumedepletionsecondarytohyperemesis, hemorrage of spontaneusabortion, septicabortus, Gram-negativesepsis, myoglobulinuriasecondarytoClostridiuminducedmyonecrosis of uterus 3.Renalcorticalnecrosis
Renal Cortical Necrosis • Frequentlyseen in olderwomen, multigravidas, multiplgestations • Causes: abruptioplacentae, septicabortion, severe preeclampsia, amnioticfluidembolism, retainedfetus • Presentswithgrosshematuria, flankpain, severe oliguriaoranuria • Renalfunctionalrecoveryrequiresmontsand is incomplete, mayleadto ESRD
Acute Renal Failure in Pregnancy • Latepregnancy 1. Acutetubularnecrosis→ preeclampsia, HEELP syndrome, bleeding in abruptioplacentae 2. Acutefattyliver of pregnancy→ presentafter 34 weekwithjaundiceandabdminalpain; associatedwith ARF
Acute Renal Failure in Pregnancy 3.Postpartum acute renal failure and thrombotic thrombocytopenic purpura- hemolytic uremic syndrome -presents with severe HT, microangiopathic hemolytic anemia, thrombocytopenia and ARF days to weeks after normal pregnancy -patients can have severe deficiency of ADAMSTS-13 activity
Acute Renal Failure in Pregnancy 3.Postpartum acute renal failure and thrombotic thrombocytopenic purpura- hemolytic uremic syndrome -Retained placental fragments may play a role -major clinical issue is to differantiate from preeclampsia and HEELP syndrome -Treatment: plasma exchange or plasmapheresis
What Did We Learn? • - Cardiovascularandrenalhemodynamicchanges in normal pregnancy • Preaclampsia-eclampsia • Chronichypertension • Preeclampsia-eclampsiasuperimposedchronichypertension • Gestationalhypertension • Maternalevaluation • Indicationfortreatment of hypertensivedisorders • Acutetherapy • Long-term oral therapy