Hypertension in Pregnancy

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Hypertension in Pregnancy

• N.L. Meyer, M.D.

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Hypertension in Pregnancy

• Most common medical disorder during pregnancy
• Gestational hypertension preeclampsia
• 70 of HTN in pregnancy
• Wide spectrum
• Mild elevation in BP vs severe hypertension with
  organ dysfunctions
• Acute gestational hypertension
• Preeclampsia
• Eclampsia
• HELLP

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Hypertension in Pregnancy
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Gestational Hypertension

• Systolic BP 140 and /or diastolic 90 on at
  least 2 occasions at least 6 hours apart after 20
  weeks in women known to be normotensive before
  pregnancy and before 20 weeks gestation
• BP recordings should be no more than 7 days apart
• Severe gestational hypertension
• Sustained elevations in systolic BP 160 and /or
  diastolic BP 110 for 6 hours

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Gestational Hypertension

• Most frequent cause of HTN during pregnancy
• 6 -17 in healthy nulliparous patients
• 2 - 4 in multiparous patients
• Rates increase
• Previous preeclampsia
• Multifetal gestations

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Gestational Hypertension

• Progression
• Gestational age at diagnosis
• 50 progression with diagnosis prior to 30 weeks
• Severe hypertension
• Preeclampsia
• Eclampsia
• Undiagnosed hypertension

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Gestational Hypertension

• Most cases develop 37 weeks
• Overall outcome similar to or better than
  normotensive pregnancies
• Higher gestational age at delivery
• Higher birth weight
• Higher rates of induction
• Higher cesarean section rates

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Mild Gestational Hypertension
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Mild Gestational Hypertension
Management

• Increased risks for progression
• Close maternal and fetal assessment

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Mild Gestational Hypertension

• Maternal Evaluation
• Weekly prenatal visits
• Reporting preeclamptic symptoms
• Laboratory evaluation
• CBC
• Platelets
• LFT's

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Mild Gestational Hypertension
Fetal Evaluation

• Amniotic fluid
• Estimated weight
• Weekly nonstress testing

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Mild Gestational Hypertension
Management

• Salt restriction not indicated
• Restricted activity not indicated
• Antihypertensive medication not indicated
• Continue to term
• Absence of progression
• Seizure prophylaxis not indicated

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Severe Gestational Hypertension

• Increased maternal and perinatal morbidity
• Outcomes similar to severe preeclampsia
• Abruptio placentae
• Preterm delivery
• lt 37 weeks
• lt 35 weeks
• SGA infants
• Manage as if they had severe preeclampsia

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Severe Gestational HTN vs Severe Preeclampsia
Buchbinder et al AJOG 200218666-71
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Preeclampsia

• Hypertension unique to human pregnancy
• Rarely reported in primates
• Incidence
• 3 - 7 in nulliparas
• 0.8 - 5 in multiparas
• Significantly increased in multigestations

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Risk Factors

• Nulliparity
• Family history
• Obesity
• Multifetal gestation
• Previous preeclampsia
• Previous poor outcome
• IUFD
• IUGR
• Abruption

• Preexisting medical conditions
• CHTN
• Renal disease
• Diabetes
• Thrombophilias
• APAS
• Protein S deficiency
• Protein C deficiency
• Factor V Leiden
• Abnormal dopplers

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Preeclampsia

• Gestational hypertension plus proteinuria
• 300 mg / 24 hours
• Classic triad
• Hypertension
• Proteinuria
• Edema

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Hypertension

• Systolic blood pressure of 140 mm or diastolic
  blood pressure of 90 mm after 20 weeks in a
  previously normotensive women
• "30 x 15" rule
• ? 30 mm SBP or 15 mm DBP over baseline
• No longer used
• Gradual rise in BP is seen in most normal
  pregnancies
• 73 of primigravidas demonstrate gt15 mm increase
  in DBP during pregnancy
• 67 with SBP gt 30 mm over baseline

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Hypertension
Villar and Sibai AJOG 198960419
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Hypertension

• Korotkoff phase V
• Appropriate size cuff
• Length 1.5 x upper arm circumference
• Bladder encircles gt 80 of the arm
• Upright position after 10 minutes rest
• Hospitalized
• Either sitting up or LLR position
• Arm level with heart
• No tobacco or caffeine x 30 minutes
• Mercury sphygmomanometer preferred

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Edema

• No longer considered part of the diagnosis
• Neither sufficient nor necessary to confirm
• Common finding in normal pregnancies
• 1/3 of eclamptic women do not develop edema

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Proteinuria

• 300 mg / 24 hours
• 30 mg/dL or 1 on dipstick on at least 2 random
  samples at least 6 hours apart but lt 7 days apart
• Dipstick correlates poorly with protein in a
  24-hr collection
• 1 has PPV of 92 for 300 mg / 24-hr
• Negative to trace has a NPV of only 34
• 66 have gt 300 mg / 24-hrs
• Cannot exclude significant proteinuria
• 3 to 4 have PPV of 36
• Cannot confirm significant proteinuria

Meyer et al AJOG 1994170137-41
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Proteinuria
Meyer et al AJOG 1994170137-41
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Proteinuria
Meyer et al AJOG 1994170137-41
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Proteinuria

• Can preeclampsia occur without proteinuria?
• Consider preeclampsia when gestational
  hypertension is associated with other symptoms
• Persistent cerebral symptoms
• Epigastric or right upper quadrant pain with
  nausea and vomiting
• Thrombocytopenia
• Abnormal liver enzymes
• IUGR

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Severe Preeclampsia

• Severe gestational hypertension associated with
  abnormal proteinuria
• SBP 160 mm or DBP 110 mm on 2 occasions gt 6
  hours apart at bed rest
• Hypertension in association with severe
  proteinuria
• 5 g / 24 hours

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Severe Preeclampsia

• Multiorgan involvement
• Pulmonary edema
• Seizures
• Oliguria
• lt 500 mL / 24 hours
• Thrombocytopenia
• lt 100,000 / mm3
• Abnormal LFT with persistent RUQ or epigastric
  pain
• Persistent severe CNS symptoms

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Superimposed Preeclampsia

• New onset proteinuria complicating hypertension
  prior to 20 weeks gestation
• Sudden increase in proteinuria
• Sudden increase in hypertension
• HELLP syndrome
• CHTN with HA, scotomata or epigastric pain

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Management

• Delivery is the only cure
• Primary considerations
• Safety of mother
• Delivery of a live, mature newborn
• Immediate delivery vs expectant management
• Severity of disease process
• Maternal / fetal status at initial evaluation
• Gestational age
• Labor
• Bishop score
• Maternal desire

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Mild Preeclampsia - Management

• Mild preeclampsia at term with favorable cervix
• Delivery
• Unfavorable cervix 37 weeks - ? Cervical
  ripening
• Delivery 34 weeks
• Progressive labor
• ROM
• Abnormal testing
• IUGR
• Deliver by 40 weeks even with unfavorable
  conditions

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Mild Preeclampsia - Management

• Management lt 37 weeks remains controversial
• Maternal and fetal evaluation?
• Hospitalization vs ambulatory management?
• Antihypertensive medications?
• Bed rest?

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Maternal Evaluation

• Frequent evaluation for progression of disease
• Lab evaluation
• Platelet count
• LFT's
• Renal function
• Urine protein
• Repeat weekly mild disease, no progression

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Fetal Evaluation

• Weekly antepartum fetal evaluation
• Twice weekly testing with IUGR or oligohydramnios
• Daily fetal movement assessment
• Fetal growth evaluation

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Outpatient Management

• SBP 150mm / DBP 100mm
• Urine protein 1000 mg/24 hours
• Asymptomatic
• Normal LFT's
• Platelets 1000/mm3
• Daily BP and urinalysis
• Twice weekly evaluation
• Growth and fluid assessment q 3 weeks
• Hospitalize with disease progression

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Antihypertensive Medication

• Mask diagnosis of severe disease
• Lower rates of progression to severe disease
• No demonstrated impact on perinatal outcome
• No difference in GA at delivery
• Reduction in BP has not been associated with a
  reduction in antepartum days

Sibai et al AJOG 1992167879
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Bed Rest

• No evidence that bed rest improves outcome
• No randomized trials
• Increased risk of thromboembolism

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Magnesium Sulfate Prophylaxis

• gt 70 years of use
• Intramuscular (Pritchard) and intravenous
  (Sibai) regimes
• "Standard of care" in the US
• 10 progression to severe disease with
  prophylaxis or placebo in 135 women at term
• 12.8 vs 16.8 progression in a recent
  controlled trial of MgSO4 vs placebo

Witlin, Friedman, Sibai AJOG 1997176623-7 Liv
ingston et al Ob Gyn 2003101217-220
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Severe Preeclampsia

• SBP 160mm or DBP 110mm on 2 occasions 6 hours
  apart at bed rest
• Significant proteinuria ( 5 g/24 hr)
• Oliguria lt 500 mL / 24-h
• Cerebral / visual disturbances
• Epigastric pain, nausea, vomiting
• Pulmonary edema, cyanosis
• Abnormal LFT's
• Thrombocytopenia
• IUGR

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Severe Preeclampsia

• Hospitalization
• MgSO4 prophylaxis
• Antihypertensive medication
• Maintain SBP 140 -155mm and DBP 90 -105mm
• 24 - 34 weeks
• Steroids for lung maturity
• Maternal assessment
• Fetal assessment

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Antihypertensive Medication
National High Blood Pressure Education Program
Working Group on High Blood Pressure in
Pregnancy. AJOG 2000183S1-S22.
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Antihypertensive Therapy

• Prevent potential cerebrovascular and
  cardiovascular complications
• Encephalopathy, hemorrhage, CHF
• No randomized trials to determine what level to
  treat to prevent complications
• Recommendations vary
• SBP 180mm and DBP 110mm
• SBP 160 mm or DBP 105mm
• MABP 130mm
• Sibai Ob Gyn 2003102181
• Intrapartum SBP 170mm or DBP 110mm
• Postpartum or thrombocytopenia SBP 160mm or
  DBP 105mm

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Severe Preeclampsia

• Progressive deterioration in both maternal and
  fetal conditions
• Deliver with onset after 34 weeks
• Increased rate of maternal morbidity/mortality
• Significant fetal risk
• Delivery prior to 34 weeks
• Imminent eclampsia
• Multiorgan dysfunction
• Severe IUGR
• Suspected abruption
• Non-reassuring fetal testing

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Severe Preeclampsia lt 34 Weeks

• Considerable disagreement
• Delivery is definitive therapy
• Delivery may not be optimal for the premature
  fetus
• 34 weeks deliver
• lt 23 weeks offer termination
• 33 - 34 weeks steroids with delivery after
  48-hrs
• 23 - 32 weeks gestation
• Individualized treatment based on clinical
  response during the initial 24 hours observation

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Chronic Hypertension

• 5 of pregnant women
• Hypertension before the 20th week or before
  pregnancy
• Antihypertensive medication prior to pregnancy
• Persistence beyond the usual postpartum period
• Mild chronic hypertension
• 140 / 90 mm Hg
• Severe chronic hypertension
• 180 / 110 mm Hg

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Chronic Hypertension

• Essential hypertension (90)
• Secondary hypertension (10)
• Renal
• Connective tissue
• Endocrine
• Vascular

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Chronic Hypertension

• Risks
• Superimposed preeclampsia
• 4.7 52 incidence
• Abruption
• Poor perinatal outcome
• IUGR
• IUFD
• PTD

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Low Risk Chronic HTN

• Mild essential hypertension without organ
  involvement
• Blood pressure at initial visit regardless of
  medication
• BP lt 180 / 110 mmHg
• No previous perinatal losses

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Low Risk Chronic HTN

• Usually good perinatal outcome irrespective of
  antihypertensive drugs
• 49 ? MAP
• 34 with no change in MAP
• Most poor outcomes were related to superimposed
  preeclampsia
• Discontinue antihypertensive meds
• Treat BP gt 160 / 110 mmHg to keep DBP 105 mmHg
• In absence of superimposed preeclampsia,
  pregnancy may continue
• Favorable cervix
• Labor
• Completion of 40 weeks

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High Risk Chronic HTN

• Secondary hypertension
• Maternal age gt 40
• Duration HTN gt 15 years
• Target organ damage
• Previous perinatal loss
• BP 180 / 110 mmHg

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High Risk Chronic HTN

• Antihypertensive medication
• Absent target organ damage
• Maintain BP 140 -150 / 90 -100 (140 -160 / 90
  -105)
• Target organ damage
• BP lt 140 / 90
• Close monitoring
• Fetal evaluation at 28 (as early as 26) weeks
• Superimposed preeclampsia
• Hospitalization
• Delivery with GA 34 weeks

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Medication for BP 180/110
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Superimposed Preeclampsia

• Incidence 4.7 - 52 depending on initial BP
• Exacerbation of HTN
• At least 30 mm systolic or 15 mm diastolic
• Development of proteinuria
• 500mg / 24 h
• Exacerbation of preexisting proteinuria
• 5 g / 24 h
• ? LFT's
• ? platelets
• ? uric acid gt 6 mg / dL
• Development of symptoms