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Hypertension specialist ESH
Hypertensive disorders in pregnancy: maternal fetal neonatal morbidity and mortalitya major cause of
Pregnant women with hypertensionat higher risk for abruptio placentae cerebrovascular events organ failure DIC
Fetus at higher risk for intrauterine growth retardation prematurity intrauterine death
WHO definition of hypertensionin pregnancy1. SBP > 140 mmHg or DBP > 90 mmHg
2. Rise in SBP > 25 mmHg or rise in DBP > 15 mmHg compared to pre-pregnancy values or those in the first trimester
Definition of hypertensionin pregnancySBP > 140 mmHg or DBP > 90 mmHg
Cardiovascular changes in pregnancySBPDBPMAPHRSVCO 4-6 mmHg 8-15 mmHg 6-10 mmHg 12-18 BPM 10-30% 33-45%All bottom at 20-24 wks, then rise gradually to pre-pregnancy values at term
Early 2nd trimester, then stableEarly 2nd trimester, then stablePeaks in early 2nd trimester, then until termParameter TimingMain DM, Main EK: Obstetrics and Gynecology, 1984
Definition CHS NHBPEPWG WHOHypertension,mmHg
Severe hypertensionDBP > 90
DP > 110BP > 140/90
DP > 110 orSP > 160BP > 140/90or riseSP > 25 and/orDP > 15 mmHg
DP > 110SP > 160CHS = Canadian Hypertension SocietyNHBEPWG = National High Blood Pressure Education Program Working Group (US)WHO = World Health Organization
Definition ISSH ASSH ACOGHypertension,mmHg
Severe hypertensionDP > 90
DP > 110DP > 90 and/orSP > 140, or risein SP of > 25 andin DP of > 15
DP > 110 and/orSP > 170DP > 90or SP > 140
DP > 110SP > 160-180ISSH = International Society for Study of HypertensionASSH = Australian Society for Study of HypertensionACOG = American College of Obstetricians and Gynecologists
Criterion CHS NHBPEPWG WHOKorotkoffsound
Severe proteinuria(24-h urine collection, g/d)IV
-CHS = Canadian Hypertension SocietyNHBEPWG = National High Blood Pressure Education Program Working Group (US)WHO = World Health Organization
Criterion ISSH ASSH ACOGIV
Severe proteinuria(24-hr urine collection, g/d) IV
> 0.3 or positivedipstick result of> 2+-
> 5ISSH = International Society for Study of HypertensionASSH = Australian Society for Study of HypertensionACOG = American College of Obstetricians and Gynecologists
Measurement of BP Mercury sphygmomanometer
Both Phases IV and V to be recorded
Phase IV should be used for initiating clinical investigation and management
Classification of hypertensionin pregnancy pre-existing hypertension gestational hypertension pre-existing hypertension plus superimposed gestational hypertension with proteinuria antenatally unclassifiable hypertension
Pre-existing hypertension 1-5% of pregnancies
BP > 140/90 mmHg predates pregnancy or develops before 20 weeks of gestation
In most cases, hypertension persists more than 42 days post partum, it may be associated with proteinuria
Gestational hypertensionPregnancy-induced hypertension withor without proteinuria
Hypertension develops after 20 weeksgestation, in most cases, it resolves within42 days post partum
Poor organ perfusion
Pre-existing hypertension plussuperimposed gestational hypertensionwith proteinuriaFurther worsening of BP and proteinexcretion > 3 g/day in 24-hour urine collection after 20 weeks gestation
Previous terminology chronic hypertension with superimposed pre-eclampsia
Antenatally unclassifiable hypertensionHypertension with or without systemicmanifestation
BP first recorded after 20 weeks gestation,re-assessment necessary at or after 42 dayspost partum
Gestational hypertension associated with significant proteinuria
300 mg/l or 500 mg/24 h or dipstick 2+ or more
Poor organ perfusion
Basic laboratory tests for monitoringhypertension in pregnancy Hemoglobin and hematocrit Platelet count Serum AST, ALT, LDH Proteinuria (24-h urine collection) Urinalysis Serum uric acid Serum creatinine
Platelet countHemoconcentration supports diagnosis of gestationalhypertension with or without proteinuria. It indicatesseverity. Levels may be low in very severe casesbecause of hemolysis.
Low levels < 100,000 x 109/L may suggest consumptionin the microvasculature. Levels correspond to severityand are predictive of recovery rate in post-partumperiod, especially for women with HELLP syndrome.* Basic laboratory tests for monitoring hypertension in pregnancy* HELLP Hemolysis, Elevated Liver enzyme levels and Low Platelet count
Basic laboratory tests for monitoring hypertension in pregnancySerum uric acid
SerumcreatinineElevated levels aid in differential diagnosis of gestational hypertension and may reflect severity.
Levels drop in pregnancy. Elevated levels suggestincreasing severity of hypertension; assessment of 24-h creatinine clearance may be necessary.
Basic laboratory tests for monitoring hypertension in pregnancySerum AST,ALT
Serum LDHElevated levels suggest hepatic involvement. Increasing levels suggest worsening severity.
Elevated levels are associated with hemolysis and hepatic involvement. May reflect severity and may predict potential for recovery post partum, especially for women with HELLP* syndrome.* HELLP Hemolysis, Elevated Liver enzyme levels and Low Platelet count
Basic laboratory tests for monitoring hypertension in pregnancyUrinalysis
Proteinuria(24-h urinecollection)Dipstick test for proteinuria has significant false-positiveand false-negative rates. If dipstick results are positive(> 1), 24-h urine collection is needed to confirmproteinuria. Negative dipstick results do not rule outproteinuria, especially if DBP > 90 mmHg.
Standard to quantify proteinuria. If in excess of 2g/day,very close monitoring is warranted. If in excess of 3g/day,delivery should be considered.
Management of hypertension in pregnancy
BP levels gestational age associated maternal and fetal risk factors
Non-pharmacologic management SBP 140-149 mmHg or DBP 90-99 mmHg
activity, bed rest (left lateral position)
AVOID : weight reduction and salt restriction
Emergency management of hypertension in pregnancy
SBP 170 or DBP 110 mmHghydralazine, labetalol, methyldopa or nifedipine
Thresholds for drug treatment initiation
BP > 140/90 mmHg in women with gestational hypertension without proteinuria or pre-existing hypertension before 28 weeks' gestation or gestational hypertension and proteinuria or symptoms at any time or pre-existing hypertension and TOD or pre-existing hypertension and superimposed gestational hypertension
BP > 150/95 mmHg In all other circumstances methyldopa, labetalol, calcium antagonists, and beta-blockers
AVOID: ACE inhibitors, AIIA, diuretics
magnesium sulfate: eclampsia, treatment and prevention of seizures
Br J Obstet Gynaecol 1998;105:718-22
Antihypertensive drugs used in pregnancyWomen with pre-existing hypertension are advisedto continue their current medication except for ACEinhibitors and AIIA
Antihypertensive drugs used in pregnancyCentral alfaagonists
Alfa-/beta-blockersMethyldopa is the drug of choice.
Atenolol and metoprolol appear to be safe and effectivein late pregnancy.
Labetalol has comparable efficacy with methyldopa,in case of severe hypertension, it could be givenintravenously.
Antihypertensive drugs used in pregnancyCalcium-channel blockers
ACE inhibitors,angiotensin IIantagonistsOral nifedipine or i.v. isradipine could be givenin hypertensive emergencies. Potential synergismwith magnesium sulfate may induce hypotension.
Fetal abnormalities including death can be causedand these drugs should not be used in pregnancy.
Antihypertensive drugs used in pregnancyDiuretics
DirectvasodilatorsDiuretics are recommended for chronic hypertensionif prescribed before gestation or if patients appear tobe salt-sensitive. They are not recommended inpre-eclampsia.
Hydralazine is no longer the parenteral drug of choice;perinatal adverse effects.
Does not increase BP in nursing mothers
All antihypertensive agents taken by the nursing mother are excreted into breast milk; however, most of them are present at very low concentrations, except for propranolol and nifedipine concentrations, which are similar to maternal plasma
Implications of hypertension in pregnancy
Pathophysiologic factors involved in preeclampsia
Chronic hypertension BP 140/90 mm Hg before the 20th week of gestationPreeclampsia Elevated BP ( 140/90 mm Hg) in a patient who was normotensive before 20 weeks of gestation, accompanied by Urinary excretion of 0.3 g of protein in a 24-h collectionOther features that increase the certainty of the diagnosis of preeclampsia BP 160/110 mm Hg Proteinuria 2.0 g/24 h that appears initially during pregnancy and regresses postpartum Newly-elevated se