Transcript Document
Hypertensive Disorders
in Pregnancy
Aleksandra Rajewska PhD
Chair and Department of Obstetrics
and Gynecology
Hypertensive disorders (HD)
in pregnancy
Affects 7 – 10% pregnancies
Increased perinatal morbidity & mortality
Mild hypertension in pregnancy:
33% preterm delivery; 11% SGA neonates
Severe hypertension in pregnancy:
62 – 70% preterm delivery; 40% SGA neonates
Hypertensive disorders in pregnancy:
classification
1.
2.
3.
4.
5.
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
DIC
Cerebral hemorrhage
Retinal hemorrhage
Liver insufficiency
Acute renal failure
Cardiac insufficiency
Pulmonary edema
Placental abruption
Fetal
IUGR
Low birth weight
Oligohydramnios
Preterm delivery
Neonatal prematurity
Intrauterine hypoxia
Intrauterine fetal death
Placental abruption
Ethiology
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
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
Pregnancy Induced Hypertension (PIH)
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)
2 – 7% of primiparas
14% of twin pregnancies
18% with PE in previous
pregnancy
Minimum criteria
BP ≥ 140/90 mmHg
after 20 weeks’ gestation
Proteinuria ≥ 300 mg/24
hours or ≥ 1+ dipstick
Increased certainty
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)
Pregnancy-specific syndrome of reduced
organ perfusion secondary to placental
hypoperfusion, vasospasm and endothelial
activation
Risk factors: nulliparity, multifetal
gestation, maternal age >35 years, obesity,
ethnicity
Preeclampsia (PE)
Preventive factors: placenta previa,
smoking
Histopathology: glomerular lesion
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
Typically in the third trimester
Prognosis always serious
Preventable!
Fatal coma without convulsions – dgn.
controversial
Eclampsia
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
Transient diaphragm fixation: respiratory arrest
Continuous convulsions: „status epilepticus”
Placental abruption
DIC
Massive cerebral hemorrhage
Neurological deficits
Eclampsia: sequels
Aspiration pneumonia
Pulmonary edema
Cardiopulmonary arrest
Acute renal failure
Maternal death
Eclampsia: differential diagnosis
Exclude:
Epilepsy
Encephalitis
Meningitis
Cerebral tumor
Cysticercosis
Ruptured cerebral aneurysm
Eclampsia: treatment
1.
2.
3.
4.
5.
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
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
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
Often develops earlier in pregnancy and gets
more severe than „pure” preeclampsia
All chronic hypertensive disorders predispose
to development of superimposed preeclampsia
and eclampsia!
Pathophysiology: cardiovascular system
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
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
Decrease in renin, angiotensin II &
aldosterone activity
Paradoxical sodium retention
Expanded volume of extracellular fluid:
Endothelial injury
Reduced plasma oncotic pressure
(proteinuria)
Pathophysiology: kidney
Reduced renal perfusion
Reduced glomerular filtration
Elevated plasma uric acid concentration
Proteinuria: albumins, globulins, hemoglobin &
transferrin
Pathophysiology: kidney
In mild to moderate PE: elevated plasma
creatinine values
Severe PE: intrarenal vasospasm & oliguria
Intensive intravenous fluid therapy
contraindicated!
Intravenous dopamine infusion recommended!
Patophysiology: liver
Most common in HELLP syndrome
Periportal hemorrhage described by Virchow
in 1856
Focal hemorrhages can cause hepatic rupture
or subcapsular hematoma
Patophysiology: brain
Gross hemorrhage due to ruptured arteries
caused by severe hypertension: most common in
women with underlying chronic hypertension;
PE is not necessary!
Hyperemia, ischemias, thrombosis &
hemorrhage: common in PE, universal with
eclampsia
Patophysiology: brain
Doppler findings in eclampsia: cerebral
hyperperfusion similar to hypertensive
encephalopathy
Cerebral edema
Pathophysiology: placenta
Uteroplacental perfusion compromised from
vasospasm
Most common in HELLP syndrome
Doppler velocimetry!
Prediction
Uric acid
Fibronectin
Coagulation activation
Oxidative stress
Cytokines
Placental peptides
Fetal DNA
Uterine artery Doppler velocimetry
Management: prevention?
Low-dose Aspirin
Antioixdants
No salt intake restrictions
No slimming diet!
Management: antepartum
hospitalization
Detailed examination and daily scrutiny for:
headache, visual disturbances, epigastric pain
and rapid weight gain
Everyday weight admittance
Analysis for proteinuria (every 2 days)
Management: antepartum
hospitalization
Blood pressure readings (every 4 hours)
Measurements of plasma creatinine,
hematocrit, platelets, serum liver enzymes
Frequent evaluation of fetal size and
amniotic fluid volume
Management: conservative
antihypertensive therapy
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
Nifedipine, werapamil: Ca channel blockers
Contraindicated in I trimester!
Contraindicated if high risk of eclampsia
(magnesium sulfur administration causes
hypotony)
Dihydralazin: in severe hypertension
Management: termination of
pregnancy
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
PIH: recovery in few days
Hypotensive agents: 3 – 4 weeks postpartum
PE/E: continue magnesium sulfate
administration 24 hours postpartum
and hypotensive agents
Hypertensive disorders
in puerperium
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