Hypertensive Disorders in Pregnancy

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Hypertensive Disorders in Pregnancy

• Aleksandra Rajewska PhD
• Chair and Department of Obstetrics
• and Gynecology

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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

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Hypertensive disorders in pregnancy
classification

1. Pregnancy Induced Hypertension (PIH) or
   Gestational Hypertension (GH) or Transient
   Hypertension
2. Preeclampsia
3. Eclampsia
4. Chronic hypertension
5. Preeclampsia superimposed on chronic hypertension

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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

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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

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Spiral arteries modification
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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?

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Pathogenesis

• Vasospasm
• Endothelial cell activation
• Increase pressor response
• Coagulation promotion

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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 lt 12 weeks
  postpartum
• No proteinuria
• Edema is not a PIH criterion any more!
• Final diagnosis postpartum

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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 gt1,2 mg/dL
• Persistent headache or other cerebral or visual
  disturbances
• Persistent epigastric pain

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Preeclampsia (PE)

• Pregnancy-specific syndrome of reduced organ
  perfusion secondary to placental hypoperfusion,
  vasospasm and endothelial activation
• Risk factors nulliparity, multifetal gestation,
  maternal age gt35 years, obesity, ethnicity

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Preeclampsia (PE)

• Preventive factors placenta previa, smoking
• Histopathology glomerular lesion
• In severe cases proteinuria may fluctuate over
  any 24-hours period

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Eclampsia

• Generalized tonic-clonic convulsions (beginning
  about facial muscles)
• with subsequent coma
• in a woman with preeclampsia

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Eclampsia

• Typically in the third trimester
• Prognosis always serious
• Preventable!
• Fatal coma without convulsions dgn.
  controversial

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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

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Eclampsia sequels

• Transient diaphragm fixation respiratory arrest
• Continuous convulsions status epilepticus
• Placental abruption
• DIC
• Massive cerebral hemorrhage
• Neurological deficits

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Eclampsia sequels

• Aspiration pneumonia
• Pulmonary edema
• Cardiopulmonary arrest
• Acute renal failure
• Maternal death

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Eclampsia differential diagnosis

• Exclude
• Epilepsy
• Encephalitis
• Meningitis
• Cerebral tumor
• Cysticercosis
• Ruptured cerebral aneurysm

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Eclampsia treatment

• 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 gt 100 mmHg
• Avoid diuretics and limitations of fluid
  administration!
• DELIVERY
• Magnesium sulfate in eclampsia is given as
  anticonvulsant, not as hypertension treatment!

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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

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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

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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!

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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

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Patophysiology blood coagulation

• Acute thrombocytopenia lt 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!

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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)

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Pathophysiology kidney

• Reduced renal perfusion
• Reduced glomerular filtration
• Elevated plasma uric acid concentration
• Proteinuria albumins, globulins, hemoglobin
  transferrin

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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!

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Patophysiology liver

• Most common in HELLP syndrome
• Periportal hemorrhage described by Virchow in
  1856
• Focal hemorrhages can cause hepatic rupture or
  subcapsular hematoma

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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

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Patophysiology brain

• Doppler findings in eclampsia cerebral
  hyperperfusion similar to hypertensive
  encephalopathy
• Cerebral edema

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Pathophysiology placenta

• Uteroplacental perfusion compromised from
  vasospasm
• Most common in HELLP syndrome
• Doppler velocimetry!

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Prediction

• Uric acid
• Fibronectin
• Coagulation activation
• Oxidative stress
• Cytokines
• Placental peptides
• Fetal DNA
• Uterine artery Doppler velocimetry

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Management prevention?

• Low-dose Aspirin
• Antioixdants
• No salt intake restrictions
• No slimming diet!

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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)

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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

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Management conservative antihypertensive therapy

• Aim to prolong pregnancy and/or modify perinatal
  outcomes
• a metyldopa central peripheral action no
  compromise of fetal hemodynamics
• Labetalol aß blocker

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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

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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

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Hypertensive disordersin puerperium

• PIH recovery in few days
• Hypotensive agents 3 4 weeks postpartum
• PE/E continue magnesium sulfate administration
  24 hours postpartum
• and hypotensive agents

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Hypertensive disordersin 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

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Thank you