Hypertension in Pregnancy

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Hypertension in Pregnancy
Ayoub innabi
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DEFINITIONS OF PREGNANCY-RELATED HYPERTENSIVE
DISORDERS

• There are four major hypertensive disorders
  related to pregnancy
• -Pre- eclampsia
• Eclampsia
• HELLP
• -Chronic/preexisting hypertension
• -Preeclampsia superimposed upon
  chronic/preexisting hypertension
• -Gestational hypertension

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Chronic/preexisting hypertension

• Systolic pressure 140 mmHg
• and/or diastolic pressure 90 mmHg
• -That antedates pregnancy or is present before
• the 20th week of pregnancy (on at least two
• occasions) or persists longer than 12 weeks
• postpartum.
• -It can be primary (essential hypertension) or
• secondary to a variety of medical disorders

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Preeclampsia superimposed upon chronic/preexisting
hypertension

• Superimposed preeclampsia is defined by the
• new onset of proteinuria after 20 weeks of
• gestation in a woman with chronic/preexisting
  hypertension.

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Gestational hypertension

• Gestational hypertension refers to hypertension
  without proteinuria or other signs/symptoms of
  preeclampsia that develops after 20 weeks of
  gestation.
• It should resolve by 12 weeks postpartum.
• If it persists beyond 12 weeks postpartum, the
  diagnosis is revised to chronic/preexisting
  hypertension that was masked by the physiologic
  decrease in blood pressure that occurs in early
  pregnancy.

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Criteria for Gestational Hypertension

• Systolic blood pressure 140 mmHg
• OR Diastolic blood pressure 90 mmHg
• AND no proteinuria Developing
• AFTER the 20th week of gestation in women
• known to be normotensive before pregnancy.
• - Blood pressure should be elevated on at least
• two occasions at least six hours apart.

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Pre-eclampsia
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Definitions

• Preeclampsia refers to the new onset of
  hypertension and proteinuria after 20 weeks of
  gestation in a previously normotensive woman.

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Definitions

• Preeclampsia can be classified as severe when
• Severe hypertension,
• or severe proteinuria,
• or other signs/symptoms of end-organ injury are
  present.
• In the absence of any of these findings,
  preeclampsia can be classified as mild. In this
  commonly used system, there is no moderate
  classification.

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Criteria for Diagnosis of Preeclampsia

• Systolic blood pressure 140 mmHg
• or Diastolic blood pressure 90 mmHg
• and Proteinuria 0.3 grams in a 24-hour urine
• specimen

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Incidence

• Preeclampsia occurs in up to 7.5 percent of
  pregnancies worldwide

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Risk Factors of Pre-eclampsia

• Maternal Factors
• 1. Demographic criteria
• Primagravida
• Age extremes (lt18 years, gt 34 years).
• Black race
• High body mass index (26.1)
• Male partner whose mother had preeclampsia
• 2- Medical complications
• DM , Chronic HTN, Pre-existing renal disease ,
  thrombophilia , Antiphospholipid antibody
  syndrome.
• 3- Past Hx or FHx of pregnancy-induced HTN.

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Risk Factors of Pre-eclampsia

• Fetal factors
• Hydatidiform mole
• gt 1 fetus
• fetal hydrops
• Unexplained fetal growth restriction

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Risk Factors of Pre-eclampsia

• -A past history of preeclampsia Risk 7-fold
• -Primigravid state is a significant predisposing
  factor. One theory is that
• these women may have had limited recent exposure
  to paternal antigens,
• which may play a role in the pathogenesis of the
  disease.
• -A family history of preeclampsia in a first
  degree relative, suggesting a
• heritable mechanism in some cases. The father of
  the baby may contribute to
• the increased risk, as the paternal contribution
  to fetal genes may have a role
• in defective placentation and subsequent
  preeclampsia.
• -Women who smoke cigarettes have a lower risk of
  preeclampsia than
• nonsmokers.

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Mechanisms behind preeclampsia

• Not certain.
• Numerous maternal, paternal, and fetal factors
  have been implicated in development.
• The factors currently considered to be the most
  important include the following
• Maternal immunologic intolerance
• Abnormal placental implantation
• Genetic, nutritional, and environmental factors
• Cardiovascular and inflammatory changes

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Pathogenesis of Pre-eclampsia

• As the term toxemia indicates, the search for a
  toxin has been long fruitless.
• Uteroplacental ischemia is the center to the
  development of disease, results in production of
  toxin that enters circulation ? widespread
  endothelial dysfunction.

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Severe pre-eclampsia

• Less common.
• Can be diagnosed on basis of
• Severe HTN (BP 160 / 110 mm Hg) on two
  occasions at least six hours apart. OR
• Severe proteinuria (3-4 dipstick OR gt 5 g / 24
  hr) alone without symptoms. OR
• Only mild HTN proteinuria if signs and symptoms
  are present

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Cont

• Resp Plum. Edema, cyanosis.
• Renal Proteinuria, ? Serum creatinine,
  Oliguria lt500 mL in 24 hours.
• Hepatic ? LFTs
• Neurologic visual disturbance (i.e. scotomas,
  loss of peripheral vision), headache,
  convulsions.
• Symptoms of liver capsule distention Right upper
  quadrant or epigastric pain Nausea, vomiting.
• Hematologic thrombocytopenia, microangiopathic
  hemolysis.
• Fetal growth restriction

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Eclampsia

• Latin convulsions
• Unexplained tonic-clonic seizures Mild /
  severe pre-eclampsia.
• Most often occurs intra-partum, but can also
  occur ante-partum post-partum.

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• An eclamptic seizure is typically tonic-clonic
  lasts
• 60 to 75 seconds.
• Symptoms that may occur before the seizure
• include persistent frontal or occipital headache,
• blurred vision, photophobia, right upper quadrant
• or epigastric pain, and altered mental status.
• In up to one-third of cases, there is no
  proteinuria
• or blood pressure is less than 140/90 mmHg prior
• to the seizure

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Summary of maternal and neonatal outcomes in
eclampisa

• Abruption 7
  to 10
• DIC
  7 to 11
• Pulmonary edema 3 to 5
• Acute renal failure 5 to
  9
• Aspiration pneumonia 2 to 3
• Cardiopulmonary arrest 2 to 5
• Liver hematoma 1
• HELLP syndrome 10 to
  15
• Perinatal death 5.6
  to 11.8
• Preterm birth 50

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Cont

• HELLP syndrome
• Type of severe pre-eclampsia.
• Hemolysis Elevated Liver enzymes Low
  Platelets.

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Signs and Symptoms

• Severe hypertension (systolic blood pressure 160
  mm Hg or diastolic 110 mm Hg on two occasions at
  least six hours apart)
• Persistent and/or severe headache,
• Visual abnormalities (scotomata, photophobia,
  blurred vision, or temporary blindness rare)
• Upper abdominal or epigastric pain
• Nausea, vomiting
• Oliguria
• Dyspnea, retrosternal chest pain
• Fetal growth restriction
• Oligohydramnios
• Altered mental status

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Laboratory abnormalities

• Hemoconcentration
• Microangiopathic hemolytic anemia (abnormal
  peripheral smear, elevated bilirubin, or low
  serum haptoglobin levels U/L)
• Thrombocytopenia (lt100,000/microL)
• Elevated serum creatinine concentration (gt1.3
  mg/dL)
• Elevated liver enzymes (twice the upper limit of
  normal)
• Severe proteinuria (5 grams in 24 hours)

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Atypical presentation

• Include any of the following
• Onset of signs/symptoms at lt20 weeks of gestation
  
• Hypertension or proteinuria (but not both) with
  or without characteristic signs and symptoms of
  severe preeclampsia
• Delayed postpartum onset or exacerbation of
  disease (gt2 days postpartum)

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Complications

• Maternal
• Cerebral hemorrhage (50 of deaths).
• LVF / Pulm. edema.
• Liver / renal dysfunction.
• Seizures.
• DIC.
• Abruptio placenta ante-partum painful vaginal
  bleeding.
• Fetal Mainly due to placental insufficiency
• Fetal loss.
• IUGR.
• Prematurity.

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Management of pre-eclampsia

• The optimal management of a woman with
• preeclampsia depends on
• Gestational age.
• Disease severity.
• Because delivery is the only cure for
• preeclampsia, clinicians must try to minimize
• maternal risk while maximizing fetal maturity.

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Management of pre-eclampsia

• Deliveries with mild preeclampsia are often
  induced after 37 weeks' gestation.
• Before this, the immature fetus is treated with
  expectant management with corticosteroids to
  accelerate lung maturity in preparation for early
  delivery.
• In patients with severe preeclampsia, induction
  of delivery should be considered after 34 weeks'
  gestation.
• In these cases, the severity of disease must be
  weighed against the risks of infant prematurity.

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Care in Mild Preeclampsia

• Hospitalized and monitored carefully
• A pregnancy complicated by mild preeclampsia at
  or beyond 37 weeks should be delivered
• Delivery is recommended if a patient is at 34
  weeks' gestation or more and has
• Ruptured membranes,
• Abnormal fetal testing,
• Progressive labor, or
• Fetal growth restriction in the setting of mild
  preeclampsia.

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Care in Mild Preeclampsia

• Expectant management of women with mild
  preeclampsia consists of
• Frequent laboratory monitoring (platelet count,
  liver and renal function tests),
• Assessment of maternal blood pressure and
  symptoms, and
• Evaluation of fetal growth and well-being.

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Treatment of Hypertension

• The use of antihypertensive drugs to control
  mildly elevated blood pressure in the setting of
  preeclampsia does not alter the course of the
  disease or diminish perinatal morbidity or
  mortality, and should be avoided.
• Sodium restriction and diuretics have no role in
  routine therapy

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Care in Severe Preeclampsia

• When severe preeclampsia is diagnosed after 34
  weeks' gestation, delivery is most appropriate.
• But if patient appears to be stable, and if the
  fetal condition is reassuring, expectant
  management may be considered.

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Criteria for delivery

• Women with severe preeclampsia who are managed
  expectantly must be delivered under the following
  circumstances
• Nonreassuring fetal heart status
• Uncontrollable BP
• Oligohydramnios, with amniotic fluid index (AFI)
  of less than 5 cm
• Severe intrauterine growth restriction in which
  the estimated fetal weight is less than 5
• Oliguria (lt 500 mL/24 h)
• Serum creatinine level of at least 1.5 mg/dL
• Pulmonary edema
• Shortness of breath or chest pain with pulse
  oximetry of lt 94 on room air
• Headache that is persistent and severe
• Right upper quadrant tenderness
• Development of HELLP syndrome

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Acute Treatment of Severe Hypertension in
Pregnancy

• Hydralazine
• Direct peripheral arteriolar vasodilator
• In the past, was widely used as the first-line
  treatment for acute hypertension in pregnancy.
• Slow onset of action (10-20 min), peaks
  approximately after 20 minutes
• IV bolus dose of 5-10 mg, depending on the
  severity of hypertension, may be administered
  every 20 minutes up to a maximum dose of 30 mg.
• S/E headache, nausea, and vomiting.
• May result in maternal hypotension, resulting in
  nonreassuring fetal heart rate tracing

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Acute Treatment of Severe Hypertension in
Pregnancy

• Labetalol
• Selective alpha blocker and nonselective beta
  blocker produces vasodilatation.
• 20 mg IV with repeat doses (40, 80, 80, and 80
  mg) every 10 minutes. Maximum dose of 300 mg.
• Decreases in BP after 5 minutes (in contrast to
  hydralazine).
• Decreases supraventricular rhythm and slows the
  heart rate, reducing myocardial oxygen
  consumption.
• No change in afterload is observed after
  treatment with labetalol.
• S/E dizziness, nausea, and headaches.
• Oral maintenance dose can be started after IV

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Acute Treatment of Severe Hypertension in
Pregnancy

• Calcium channel blockers
• Arteriolar smooth muscle vasodilatation by
  blocking calcium entry into the cells.
• Nifedipine is the oral calcium channel blocker
  that is used in the management of hypertension in
  pregnancy.
• 10 mg PO every 15-30 minutes, max 3 doses.
• S/E tachycardia, palpitations, and headaches.
• Avoid CCB with MgSO4
• Postpartum in patients with preeclampsia, for BP
  control.

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Acute Treatment of Severe Hypertension in
Pregnancy

• Sodium Nitroprusside
• In a severe hypertensive emergency, given when
  others failed to lower BP,
• Release of nitric oxide vasodilation.
• Preload and afterload decreased.
• Onset of action is rapid
• Severe rebound hypertension may result.
• Cyanide poisoning may occur in the fetus. Should
  be reserved for postpartum care or just before
  the delivery of the fetus

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Seizure Prophylaxis

• Recommended for women with severe preeclampsia
• Less clear benefit in mild preeclampsia
• Magnesium sulfate rather than phenytoin is
  recommended for seizure prophylaxis.
• A loading dose of 6 grams magnesium sulfate
  intravenously over 15 to 20 minutes followed by 2
  grams per hour as a continuous infusion.
• The maintenance dose (but not the loading dose)
  should be adjusted in women with renal
  insufficiency.

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MgSO4 Toxicity

• Calcium gluconate (1 gram intravenously over 5 to
  10 minutes) should be administered to counteract
  life-threatening symptoms of magnesium toxicity.
  
• Magnesium toxicity is related to serum
  concentration
• Loss of deep tendon reflexes occurs at 8 to 10
  mEq/L,
• Respiratory paralysis at 10 to 15 mEq/L,
• Cardiac arrest at 20 to 25 mEq/L.

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Prognosis

• Morbidity and Mortality
• Worldwide, preeclampsia and eclampsia responsible
  for approximately 14 of maternal deaths/year
  (50,000-75,000).
• Morbidity and mortality in preeclampsia and
  eclampsia are related to the following
  conditions
• Systemic endothelial dysfunction
• Vasospasm and small-vessel thrombosis leading to
  tissue and organ ischemia
• CNS events, such as seizures, strokes, and
  hemorrhage
• Acute tubular necrosis
• Coagulopathies
• Placental abruption in the mother

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Recurrence

• Recurrence risk of preeclampsia approximately
  10.
• Previous history of severe preeclampsia
  (including HELLP syndrome and/or eclampsia),
  recurrence risk of preeclampsia is 20.
• Recurrence risk of HELLP syndrome is 5 and of
  eclampsia is 2.
• Earlier disease during the index pregnancy,
  higher chance of recurrence.
• If before 30 weeks' gestation, recurrence may be
  as high as 40

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Questions??!!