Transcript Document

Hypertensive Disorders
in Pregnancy
Aleksandra Rajewska PhD
Chair and Department of Obstetrics
and Gynecology
Hypertensive disorders (HD)
in pregnancy
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Affects 7 – 10% pregnancies
Increased perinatal morbidity & mortality
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Mild hypertension in pregnancy:
33% preterm delivery; 11% SGA neonates
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Severe hypertension in pregnancy:
62 – 70% preterm delivery; 40% SGA neonates
Hypertensive disorders in pregnancy:
classification
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Pregnancy Induced Hypertension (PIH) or
Gestational Hypertension (GH) or Transient
Hypertension
Preeclampsia
Eclampsia
Chronic hypertension
Preeclampsia superimposed on chronic
hypertension
Maternal & fetal consequences of HD
Maternal
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DIC
Cerebral hemorrhage
Retinal hemorrhage
Liver insufficiency
Acute renal failure
Cardiac insufficiency
Pulmonary edema
Placental abruption
Fetal
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IUGR
Low birth weight
Oligohydramnios
Preterm delivery
Neonatal prematurity
Intrauterine hypoxia
Intrauterine fetal death
Placental abruption
Ethiology
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Incomplete trophoblastic invasion of uterine vessels:
Uteroplacental blood flow impairment
Diminished placental perfusion
Immunological factors:
Microscopic changes: acute graft rejection
Impairment of blocking antibodies formation
Th1/Th2 imbalance
Anticardiolipin antibodies
Spiral arteries modification
Ethiology
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Vasculopathy & inflammatory changes
Placental ischemia: released factors provoke
endothelial injury
Oxidative stress: formation of self-propagating
lipid peroxides
Nutritional factors
Antioxidants deficiency
Obesity & atherosclerosis
Genetic factors: primipaternity?
Pathogenesis
Vasospasm
 Endothelial cell activation
 Increase pressor response
 Coagulation promotion
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Pregnancy Induced Hypertension (PIH)
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6 – 17% of primiparas
2 – 4% of multiparas
Blood pressure ≥ 140/90 mmHg
occurring for first time during
pregnancy
Blood pressure returns to normal
< 12 weeks postpartum
No proteinuria
Edema is not a PIH criterion any
more!
Final diagnosis – postpartum
Preeclampsia (PE)
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2 – 7% of primiparas
14% of twin pregnancies
18% with PE in previous
pregnancy
Minimum criteria
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BP ≥ 140/90 mmHg
after 20 weeks’ gestation
Proteinuria ≥ 300 mg/24
hours or ≥ 1+ dipstick
Increased certainty
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BP ≥ 160/110 mmHg
Proteinuria ≥ 2.0 g/24 hours
or ≥ 2+ dipstick
Serum creatinine >1,2 mg/dL
Persistent headache or other
cerebral or visual
disturbances
Persistent epigastric pain
Preeclampsia (PE)
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Pregnancy-specific syndrome of reduced
organ perfusion secondary to placental
hypoperfusion, vasospasm and endothelial
activation
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Risk factors: nulliparity, multifetal
gestation, maternal age >35 years, obesity,
ethnicity
Preeclampsia (PE)
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Preventive factors: placenta previa,
smoking
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Histopathology: glomerular lesion
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In severe cases proteinuria may fluctuate
over any 24-hours period
Eclampsia
Generalized tonic-clonic convulsions
(beginning about facial muscles)
with subsequent coma
in a woman with preeclampsia
Eclampsia
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Typically in the third trimester
Prognosis always serious
Preventable!
Fatal coma without convulsions – dgn.
controversial
Eclampsia
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Antepartum 38 – 53%
Intrapartum 18 – 36%
Postpartum 11 – 44%
Life threatening for mother & fetus!
Maternal mortality: 1,8 – 14%
Fetal/neonatal mortality: the earlier in
pregnancy E occurs the higher
Eclampsia: sequels
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Transient diaphragm fixation: respiratory arrest
Continuous convulsions: „status epilepticus”
Placental abruption
DIC
Massive cerebral hemorrhage
Neurological deficits
Eclampsia: sequels
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Aspiration pneumonia
Pulmonary edema
Cardiopulmonary arrest
Acute renal failure
Maternal death
Eclampsia: differential diagnosis
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Exclude:
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Epilepsy
Encephalitis
Meningitis
Cerebral tumor
Cysticercosis
Ruptured cerebral aneurysm
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Eclampsia: treatment
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Loading dose of magnesium sulfate i.v.*
Continuous infusion of magnesium sulfate i.v. or
periodic i.m. injections
Antihypertensive medication (i.v. or oral) if diastolic
pressure > 100 mmHg
Avoid diuretics and limitations of fluid administration!
DELIVERY
* Magnesium sulfate in eclampsia is given as anticonvulsant, not as
hypertension treatment!
Chronic hypertension
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Blood pressure ≥ 140/90 mmHg before
pregnancy or diagnosed before 20 weeks’
gestation
or
Hypertension first diagnosed after 20 weeks’
gestation
or
Hypertension persistent after 12 weeks’
postpartum
Superimposed preeclampsia
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New-onset proteinuria ≥ 300 mg/24 hours
in hypertensive woman
A sudden increase in proteinuria or blood pressure
in woman with hypertension and proteinuria
before 20 weeks’ gestation
Superimposed preeclampsia
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Often develops earlier in pregnancy and gets
more severe than „pure” preeclampsia
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All chronic hypertensive disorders predispose
to development of superimposed preeclampsia
and eclampsia!
Pathophysiology: cardiovascular system
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Increased cardiac afterload caused by hypertension
Cardiac preload affected by hypovolemia
Hemoconcentration: a consequence of general
vasoconstriction and vascular permeability
Excessive reaction to even normal blood loss at
delivery
Patophysiology: blood & coagulation
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Acute thrombocytopenia < 100 000/µL
Fragmentation hemolysis (microangiopathic h.):
elevated serum lactate dehydrogenase levels
HELLP syndrome: Hemolysis, ELevated liver
transaminase enzymes, Low Platelets
0,2 – 0,6% of all pregnancies
4 – 12% of pregnancies complicated by PE or E
But 15% of pregnancy without hypertension or
proteinuria!
Patophysiology: volume homeostasis
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Decrease in renin, angiotensin II &
aldosterone activity
Paradoxical sodium retention
Expanded volume of extracellular fluid:
Endothelial injury
Reduced plasma oncotic pressure
(proteinuria)
Pathophysiology: kidney
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Reduced renal perfusion
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Reduced glomerular filtration
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Elevated plasma uric acid concentration
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Proteinuria: albumins, globulins, hemoglobin &
transferrin
Pathophysiology: kidney
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In mild to moderate PE: elevated plasma
creatinine values
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Severe PE: intrarenal vasospasm & oliguria
Intensive intravenous fluid therapy
contraindicated!
Intravenous dopamine infusion recommended!
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Patophysiology: liver
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Most common in HELLP syndrome
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Periportal hemorrhage described by Virchow
in 1856
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Focal hemorrhages can cause hepatic rupture
or subcapsular hematoma
Patophysiology: brain
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Gross hemorrhage due to ruptured arteries
caused by severe hypertension: most common in
women with underlying chronic hypertension;
PE is not necessary!
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Hyperemia, ischemias, thrombosis &
hemorrhage: common in PE, universal with
eclampsia
Patophysiology: brain
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Doppler findings in eclampsia: cerebral
hyperperfusion similar to hypertensive
encephalopathy
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Cerebral edema
Pathophysiology: placenta
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Uteroplacental perfusion compromised from
vasospasm
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Most common in HELLP syndrome
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Doppler velocimetry!
Prediction
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Uric acid
Fibronectin
Coagulation activation
Oxidative stress
Cytokines
Placental peptides
Fetal DNA
Uterine artery Doppler velocimetry
Management: prevention?
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Low-dose Aspirin
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Antioixdants
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No salt intake restrictions
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No slimming diet!
Management: antepartum
hospitalization
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Detailed examination and daily scrutiny for:
headache, visual disturbances, epigastric pain
and rapid weight gain
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Everyday weight admittance
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Analysis for proteinuria (every 2 days)
Management: antepartum
hospitalization
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Blood pressure readings (every 4 hours)
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Measurements of plasma creatinine,
hematocrit, platelets, serum liver enzymes
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Frequent evaluation of fetal size and
amniotic fluid volume
Management: conservative
antihypertensive therapy
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Aim: to prolong pregnancy and/or modify
perinatal outcomes
α – metyldopa: central & peripheral action; no
compromise of fetal hemodynamics
Labetalol: αβ – blocker
Management: conservative
antihypertensive therapy
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Nifedipine, werapamil: Ca channel blockers
Contraindicated in I trimester!
Contraindicated if high risk of eclampsia
(magnesium sulfur administration causes
hypotony)
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Dihydralazin: in severe hypertension
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Management: termination of
pregnancy
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Delivery is the cure for preeclampsia!
Mild PE + fetal prematurity: temporizing
Moderate to severe PE: labor preinduction &
induction
Severe PE or unfavorable cervix: elective
caesarian section
Subarachnoid analgesia recommended
Hypertensive disorders
in puerperium
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PIH: recovery in few days
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Hypotensive agents: 3 – 4 weeks postpartum
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PE/E: continue magnesium sulfate
administration 24 hours postpartum
and hypotensive agents
Hypertensive disorders
in puerperium
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Eclampsia in puerperium – most common in
first 48 hours postpartum; incidentally up to 4
weeks postpartum
Chronic hypertension – risk of cardiac failure,
pulmonary edema, renal failure, encephalopathy
Thank you