HYPERTENSION IN PREGNANCYPREECLAMPSIA

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HYPERTENSION IN PREGNANCY-PREECLAMPSIA

• Association of Medical Doctors in Malawi Meeting
• Sun n Sand
• Bonus Makanani

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Outline of the presentation

• Introduction
• Definition
• Classification
• Pathophysiology
• General management issues
• Pharmacotherapeutic Options for treatment
• Conclusion

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INTRODUCTION

• Hypertensive disorders in pregnancy are common
• -complicate 10 of all pregnancies
• -leading cause of maternal morbidity and
  mortality, 100000 women deaths/year
• -significant perinatal morbidity and mortality
• Correct classification important for appropriate
  management

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DEFINITION

• Level above which?pathological consequences for
  both mother and fetus
• Bp140/90,sitting position, or supine with left
  lateral tilt, at the heart level
• Korotkoff 5 (ISSHP), 2 readings 4hrs apart
• Note Automated systems systematically
  underestimate systolic pressure in preeclampsia

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CLASSIFICATION

• Several classification systems
• Simplest classification has two categories
• -chronic hypertension and preeclampsia
• Others include
• -Davey and MacGillivray classification
• -The National High Blood Pressure Education
  Program (NHBPEP)

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PRE-ECLAMPSIA/ECLAMPSIA

• Pregnancy-specific syndrome of reduced organ
  perfusion secondary to vasospasms and endothelial
  activation
• -hypertension (Bp140/90 after 20 weeks
  gestation), proteinuria as some signs
• (300mg/24hrs or 30mg/dL1 dipstick)
• Mild versus severe disease
• Seizureseclampsia stroke, neoplasia

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RISK FACTORS

• Nulliparity
• Multiple pregnancy
• Chronic hypertension/older age
• Obesity
• Race/ethnicity
• Microvascular disease eg DM
• Connective tissue disorders

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PATHOPHYSIOLOGY

• Must account for the following observations
• Exposed to chorionic villi for the first time
• Exposed to abundance of villi eg twins
• Have pre-existing vascular disease
• Genetically predisposed to develop hypertension
  during pregnancy
• ?abnormalities in vascular endothelial damage

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POSTULATED MECHANISMS

• Abnormal trophoblastic invasion
• Maternal-fetoplacental tissue immunological
  intolerance
• Maternal maladaptation to the cardiovascular or
  inflammatory changes of normal pregnancy
• Genetic influences
• Dietary deficiences

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MECHANISMS II

• Altered maternal immune response
• Premature halt to trophoblastic invasion
• Vessels remain narrow and vasoreactive
• Placental vessel resistance, poor perfusion
• Placenta releases factors to improve perfusion ?
  angiogenic factors
• Tyrosine kinase-placental growth factor, vascular
  endothelial growth factor
• Decreased angiogenesis, disturbilization/dysfuncti
  on of maternal endothelium

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GENERAL MANAGEMENT

• Basic Objectives
• Termination of pregnancy, least trauma to mother
  and fetus
• Birth of an infant who subsequently thrives
• Complete restoration of the health of the mother
• ?Early prenatal detection, ante-partum hospital
  management, termination of pregnancy

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ANTIHYPERTENSIVE CONSIDERATIONS

• Benefit/risk ratio
• -animal/human data, gestational period,
  teratogenic potential, fetal risk, severity of
  disease etc
• Protective against cerebrovascular events
• Wide choice of medications

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ANTIHYPERTENSIVES II

• Methyl dopa, oral
• -vast experience, established safety, mild to
  disease. Onset 24-48hrs
• Hydralazine, iv
• -arteriolar vasodilator, onset 10-20mins
• 5-10mg im/iv every 15 mins. Iv infusion an
  option. Unpredictable hypotension
• Nifedipine, oral
• Ca-channel blocker, selective renal arteriolar
  vasodilation and natriuretic

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Magnesium sulphate

• Drug of choice, prevention and control of
  seizures, ?mortality
• Mechanism of action not well understood,
  -blocking Ca influx, glutamate channel
• -N-methyl-D aspartate receptor blockage in the
  hippocampus
• ?Central nervous system effect

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PREVENTION

• Low dose aspirin, calcium
• -not recommended as standard for all pregnant
  women
• -small decrease in PTD, preeclampsia, perinatal
  death is some systematic reviews
• Antioxidants, vitamins C and E
• No benefit-

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Long-term cardiovascular sequalae

• Systemic review/met-analysis American Heart
  Journal 2008
• -double the risk of
• early cardiac disease
• Peripheral arteriolar disease
• Cerebral vascular disease
• Cardiovascular mortality
• -graded relationship with severity of disease

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CONCLUSION

• Hypertensive disorders in pregnancy continue to
  be a challenge
• Proper ANC has proven beneficial in reducing
  incidences of severe disease in the developed
  world
• Similar efforts in our care of pregnant women
  should achieve the same effect
• Long-term vigilance to detect early CVD
• THANK YOU