“Hypertensive Disorders in Pregnancy”
Morbidity and Mortality
Preeclampsia and eclampsia account for 10-15% of all maternal deaths worldwide (50,000 deaths/year).
A woman dies every 7 minutes from complications related to preeclampsia (World Health Organization).
Hypertensive disorders are a major cause of perinatal morbidity and mortality (UPI, preterm birth).
Hypertensive Disorders are one of the top causes of maternal morbidity and mortality in USA and Canada. Death related to:
o Renal Failure
o Coagulopathy
o Cardiac or Liver Failure
o Placental abruption
o Eclampsia (seizures) and Stroke
Classifications of Hypertensive Disorders During Pregnancy
Gestational Hypertensive Disorders
o Gestational HTN
Onset of hypertension after 20 weeks gestation and no proteinuria
BP > 140/90 (only one pressure needs elevation; systolic OR diastolic)
Need two elevated measures at least 4 hours apart
BP returns to normal within 12 weeks postpartum
Frequently occurs with multiple gestation (twins, etc.)
o Preeclampsia
Pregnancy-specific condition
Hypertension & proteinuria develop after 20 weeks gestation
Hypertension with thrombocytopenia, or impaired liver function, or renal insufficiency, or pulmonary edema or new-onset
cerebral or visual disturbances (See Table 27-2; p.654)
o Eclampsia
Seizure activity or coma in a woman with preeclampsia with no history of a preexisting condition or seizure disorder
Occurs before, during, or after birth.
Chronic Hypertensive Disorders
o Chronic HTN
Chronic Hypertension – hypertension that existed prior to pregnancy
Hypertension persisting longer than 12 wks postpartum is classified as chronic hypertension
Superimposed preeclampsia – Chronic Hypertension w/ Superimposed Preeclampsia – difficult to diagnose; associated with
adverse maternal and fetal outcomes
Preeclampsia
Risk Factors for Preeclampsia
First pregnancy <19 yrs or >40 yrs
First pregnancy with new partner
Partner who fathered a preeclamptic pregnancy in another woman
Obesity
Pre-existing medical or genetic condition: chronic HTN, pregestational DM, connective tissue disease, thrombophilia
Common Risk Factors for Preeclampsia
o Primigravida younger than 19 or older than 40
o Preeclampsia with severe features in a previous pregnancy
o Family history (mother/sister) of preeclampsia
o Paternal history (partner previously fathered a preeclamptic pregnancy)
o African descent
o Multifetal gestation
o Maternal infection/inflammation in current pregnancy (i.e., UTI, periodontal disease)
o Preexisting Medical or genetic conditions
Chronic HTN
Renal disease
Pregestation DM
Connective tissue disease – SLE, RA
Thrombophilia
Pathophysiology
Abnormal vascular remodeling the placenta
↓ placental perfusion and hypoxia. Placental ischemia →
Release of substance toxic to endothelial cells → generalized vasospasms →
Poor tissue perfusion all organ systems, ↑ peripheral resistance, ↑ BP, ↑endothelial cell permeability →
Intravascular protein and fluid loss → ↓plasma volume
, Vasospasms cause increased BP
Arteriolar vasospasms results in decreased perfusion of placenta, kidneys, liver, and brain
Decreased perfusion in placenta leads to early degenerative aging of the placenta, and decreased oxygen and nutrients to fetus resulting in
IUGR
27-1 and 27-2
HELLP Syndrome
H = Hemolysis of RBCs
EL = Elevated Liver Enzymes
o AST > 70 (normal 4-20 units/L)
o LDH > 600 (normal 45-90 units/L)
o ALT > 50 (normal 3-21 units/L)
o Sx of hepatic damage (R upper quadrant or epigastric pain; hyperbilirubinemia)
LP = Low Platelets
o Under 100,000/mm3
o Sx of bleeding
Clinical presentation nonspecific
May
Normal Non-Pregnant Preeclampsia HELLP report
Hemoglobin, hematocrit 12-16 g/dl, 37%-47% May increase Decreased h/o
Platelets 150,000-400,000/mm3 < 100,000 <100,000
Prothrombin time (PT), 12-13 sec, 60-70 sec Unchanged Unchanged
partial thromboplastin
time (PTT)
Fibrinogen 200-400 mg/dl 300-600 mg/dl Decreased
Fibrin split products (FSP) Absent Absent or present Present
BUN 10-20 mg/dl Increased Increased
Creatinine 0.5-1.1 mg/dl >1.1 Increased
Lactase dehydrogenase 45-90 unites/l Increased Increased (>600 unites/L)
(LDH)
Aspartate 4-20 units/l Elevated Elevated >70 unites
aminotransferase (AST)
Alanine aminotransferase 3-21 units/l Elevated Increased
(ALT)
Creatinine clearance 80-125 ml/min 130-180 ml/min Decreased
Burr cells or schistocytes Absent Absent Present
Uric acid 2-6.6 mg/dl > 5.9 mg/dl >10 mg/dl
Bilirubin 0.1-1 mg/dl Unchanged or increased Increased (>1.2 mg/dl)
malaise, flu-like symptoms, epigastric or RUQ pain
Symptoms tend to worsen at night and improve during the daytime
Occurs more often in Caucasian women
Care Management
Assessment
BP Management
, o Measure BP with the woman seated or in the lateral recumbent position with the arm at heart level every one should shut up while
taking BP
o Allow 10 minutes of rest before the BP measurement
o Instruct to refrain from tobacco or caffeine use 30 minutes before the BP is taken
o Use right arm each time
o Support the arm in a horizontal position at heart level
o Use proper-sized cuff (80% of arm covered)
o Slow, steady, deflation rate
o Avg. of 2 readings at least 6 hours apart
o Use the Korotkoff phase V to record diastolic pressure
Edema – pitting =
Deep tendon reflexes (DTRs)
Clonus
24-hour urine collection – presence of proteinuria
Other s/s- HA, epigastric pain, RUQ pain, visual disturbances
Classification of Edema (Depth of Indentation)
+1 = 2 mm indentation
+2 = 4 mm indentation
+3 = 6 mm indentation
+4 = 8 mm indentation
Test for Ankle Clonus – support the leg with knee flexed… with one hand the examiner sharply dorsiflexes the foot, maintains the position for a
moment then releases the foot. Normal response is elicited when no rhythmic oscillations are felt while the foot is held in dorsiflexion.
Interventions – Mild Gestational HTN & Preeclampsia w/o Severe features
Goals of therapy are to ensure maternal safety and to deliver a healthy newborn as close to term as possible
Close monitoring of the maternal and fetal status
Can be managed at home if:
o BP less than 150/100 mmHg
o No increase in proteinuria
o Normal platelet count
o Normal liver enzymes
Mom needs to be well educated (See Teaching for Self-Management: Assessing and Reporting Clinical Signs of Preeclampsia)
Initial maternal labs: serum creatinine, platelet count, liver enzymes, 24-hr urine
Weekly labs: platelet count, liver enzymes
Also evaluated weekly for s/s of severe features: severe HAs, blurred vision, mental confusion, RUQ or epigastric pain, N/V, SOB,
decreased UO
BP monitored twice/week
Proteinuria assessed weekly
Daily fetal movement counts
NST or BPP 1x or 2x/week until birth
US evaluation of amniotic fluid status and estimated fetal weight at the time preeclampsia is dx and serially thereafter
Restricted activity may be recommended
Gentle exercise
Relaxation techniques
Regular diet
Protein (60-70 g)
Calcium (1200 mg)
Folic acid (600 mcg)
Zinc (11-12 mg)
Sodium (1.5 g)
Fluid intake (6-8 8oz glasses of H20)
Avoid alcohol and tobacco; limit caffeine
Severe Gestational HTN and Preeclampsia with Severe Features
Hospitalized immediately for a thorough evaluation of maternal-fetal status
Magnesium Sulfate (prevent eclamptic seizure)
Maternal assessment- monitoring BP, UO, cerebral status, epigastric pain, labor, vaginal bleeding
Maternal labs – platelet count, liver enzymes, serum creatinine
Continuous EFM
BPP
US (fetal growth & amniotic fluid)
Multidisciplinary plan of care
, 34 wks or greater, expedite birth after mom is stabilized (risks of continuing the pregnancy are considered greater than the risks of preterm
birth)
Less than 34 wks and no indication for giving birth immediately are candidates for expectant management
Expectant management: hospitalization, consult with perinatologist, oral antihypertensive meds, ongoing maternal and fetal assessments,
betamethasone
Intrapartum Care
o Continuous EFM
o CNS, Cardiovascular, Pulmonary, Hepatic, and Renal Systems Assessments/Evaluations
o Education and Supportive Measures
o Bedrest (quiet, darkened environment)
o Emergency drugs (See BOX 27-3 p. 664), oxygen, and suction equipment readily available
o IVFs and oral fluids (125 ml/hr)
Magnesium Sulfate
Given to prevent or treat seizures
Initial loading dose 4-6 g in 100 ml IV fluid given over 15-30 minutes
Maintenance dose 1-3 g/hr (40 grams in 1000 ml LR)
Administer IVPB using infusion pump
Therapeutic level: serum Mg level between 4-7 mEq/L
Can also be given IM
o IM route rarely used. Painful injection, absorption rate uncontrolled, can cause tissue necrosis
o Give 10-g loading dose (5g in each buttock), hopefully with procaine using Z- track technique followed by massage
o Can repeat every 4 hours (5 g)
o Usually only given while patient is in transport to tertiary center
Magnesium Sulfate is a depressant
o CNS (check VS, level of consciousness, reflexes, headache, visual disturbances, lethargic)
o Cardiovascular – will feel flushed and hot – systemic vasodilatation
o Musculoskeletal – feels “heavy” and difficult to move extremities easily
o GI – slower emptying of stomach, decreased bowel motility
Prevent toxicity by careful monitoring patient’s condition. At least hourly:
o Assess BP and respirations
o Assess DTRs and clonus
o Urine output
o LOC, HA, visual disturbances, epigastric pain
o Fetal heart rate and activity
Mild Signs of Toxicity Lethargy, muscle weakness, decreased/absent DTRs, double vision, slurred speech
Increased Toxicity Hypotension, bradycardia, bradypnea, cardiac arrest
If toxicity occurs, stop infusion, give Calcium Gluconate (10 ml of a 10% solution IVP slowly over 3 minutes to avoid dysrhythmias,
bradycardia, and ventricular fibrillation)
Magnesium Sulfate is not considered toxic to healthy fetus of normal weight but if toxicity in mother occurs, infant may be born with
hyporeflexia, bradypnea, etc. Treat infant with calcium transfusions, assisted mechanical ventilation, etc. as needed
Contraindicated for women with myasthenia gravis (can cause respiratory failure), women with heart block, myocardial insufficiency and
renal disease
Excreted via kidneys so decreased urinary output may lead to toxic levels of Magnesium Sulfate
Control of BP
Antihypertensive meds if SBP >160 mmHg or DBP >110 mmHg
Hydralazine (Apresoline)
Labetalol (Trandate)
Nifedipine (Procardia)
Methyldopa
Postpartum Care
VS, I&Os, DTRs, LOC, HA, visual disturbances, epigastric pain
Magnesium Sulfate 12-24 hrs
S/S of preeclampsia usually resolve within 48hrs after birth
May need to administer antihypertensive medication
Evaluate blood loss carefully – Methergine contraindicated
Magnesium Sulfate potentiates action of narcotics and CNS depressants and calcium-channel blockers
May need additional support for patient and family
Encourage early prenatal care with subsequent pregnancy
Eclampsia
May be preceded by premonitory signs/symptoms or may come suddenly, without warning
Tonic contraction of all body muscles precedes the tonic-clonic convulsion
Morbidity and Mortality
Preeclampsia and eclampsia account for 10-15% of all maternal deaths worldwide (50,000 deaths/year).
A woman dies every 7 minutes from complications related to preeclampsia (World Health Organization).
Hypertensive disorders are a major cause of perinatal morbidity and mortality (UPI, preterm birth).
Hypertensive Disorders are one of the top causes of maternal morbidity and mortality in USA and Canada. Death related to:
o Renal Failure
o Coagulopathy
o Cardiac or Liver Failure
o Placental abruption
o Eclampsia (seizures) and Stroke
Classifications of Hypertensive Disorders During Pregnancy
Gestational Hypertensive Disorders
o Gestational HTN
Onset of hypertension after 20 weeks gestation and no proteinuria
BP > 140/90 (only one pressure needs elevation; systolic OR diastolic)
Need two elevated measures at least 4 hours apart
BP returns to normal within 12 weeks postpartum
Frequently occurs with multiple gestation (twins, etc.)
o Preeclampsia
Pregnancy-specific condition
Hypertension & proteinuria develop after 20 weeks gestation
Hypertension with thrombocytopenia, or impaired liver function, or renal insufficiency, or pulmonary edema or new-onset
cerebral or visual disturbances (See Table 27-2; p.654)
o Eclampsia
Seizure activity or coma in a woman with preeclampsia with no history of a preexisting condition or seizure disorder
Occurs before, during, or after birth.
Chronic Hypertensive Disorders
o Chronic HTN
Chronic Hypertension – hypertension that existed prior to pregnancy
Hypertension persisting longer than 12 wks postpartum is classified as chronic hypertension
Superimposed preeclampsia – Chronic Hypertension w/ Superimposed Preeclampsia – difficult to diagnose; associated with
adverse maternal and fetal outcomes
Preeclampsia
Risk Factors for Preeclampsia
First pregnancy <19 yrs or >40 yrs
First pregnancy with new partner
Partner who fathered a preeclamptic pregnancy in another woman
Obesity
Pre-existing medical or genetic condition: chronic HTN, pregestational DM, connective tissue disease, thrombophilia
Common Risk Factors for Preeclampsia
o Primigravida younger than 19 or older than 40
o Preeclampsia with severe features in a previous pregnancy
o Family history (mother/sister) of preeclampsia
o Paternal history (partner previously fathered a preeclamptic pregnancy)
o African descent
o Multifetal gestation
o Maternal infection/inflammation in current pregnancy (i.e., UTI, periodontal disease)
o Preexisting Medical or genetic conditions
Chronic HTN
Renal disease
Pregestation DM
Connective tissue disease – SLE, RA
Thrombophilia
Pathophysiology
Abnormal vascular remodeling the placenta
↓ placental perfusion and hypoxia. Placental ischemia →
Release of substance toxic to endothelial cells → generalized vasospasms →
Poor tissue perfusion all organ systems, ↑ peripheral resistance, ↑ BP, ↑endothelial cell permeability →
Intravascular protein and fluid loss → ↓plasma volume
, Vasospasms cause increased BP
Arteriolar vasospasms results in decreased perfusion of placenta, kidneys, liver, and brain
Decreased perfusion in placenta leads to early degenerative aging of the placenta, and decreased oxygen and nutrients to fetus resulting in
IUGR
27-1 and 27-2
HELLP Syndrome
H = Hemolysis of RBCs
EL = Elevated Liver Enzymes
o AST > 70 (normal 4-20 units/L)
o LDH > 600 (normal 45-90 units/L)
o ALT > 50 (normal 3-21 units/L)
o Sx of hepatic damage (R upper quadrant or epigastric pain; hyperbilirubinemia)
LP = Low Platelets
o Under 100,000/mm3
o Sx of bleeding
Clinical presentation nonspecific
May
Normal Non-Pregnant Preeclampsia HELLP report
Hemoglobin, hematocrit 12-16 g/dl, 37%-47% May increase Decreased h/o
Platelets 150,000-400,000/mm3 < 100,000 <100,000
Prothrombin time (PT), 12-13 sec, 60-70 sec Unchanged Unchanged
partial thromboplastin
time (PTT)
Fibrinogen 200-400 mg/dl 300-600 mg/dl Decreased
Fibrin split products (FSP) Absent Absent or present Present
BUN 10-20 mg/dl Increased Increased
Creatinine 0.5-1.1 mg/dl >1.1 Increased
Lactase dehydrogenase 45-90 unites/l Increased Increased (>600 unites/L)
(LDH)
Aspartate 4-20 units/l Elevated Elevated >70 unites
aminotransferase (AST)
Alanine aminotransferase 3-21 units/l Elevated Increased
(ALT)
Creatinine clearance 80-125 ml/min 130-180 ml/min Decreased
Burr cells or schistocytes Absent Absent Present
Uric acid 2-6.6 mg/dl > 5.9 mg/dl >10 mg/dl
Bilirubin 0.1-1 mg/dl Unchanged or increased Increased (>1.2 mg/dl)
malaise, flu-like symptoms, epigastric or RUQ pain
Symptoms tend to worsen at night and improve during the daytime
Occurs more often in Caucasian women
Care Management
Assessment
BP Management
, o Measure BP with the woman seated or in the lateral recumbent position with the arm at heart level every one should shut up while
taking BP
o Allow 10 minutes of rest before the BP measurement
o Instruct to refrain from tobacco or caffeine use 30 minutes before the BP is taken
o Use right arm each time
o Support the arm in a horizontal position at heart level
o Use proper-sized cuff (80% of arm covered)
o Slow, steady, deflation rate
o Avg. of 2 readings at least 6 hours apart
o Use the Korotkoff phase V to record diastolic pressure
Edema – pitting =
Deep tendon reflexes (DTRs)
Clonus
24-hour urine collection – presence of proteinuria
Other s/s- HA, epigastric pain, RUQ pain, visual disturbances
Classification of Edema (Depth of Indentation)
+1 = 2 mm indentation
+2 = 4 mm indentation
+3 = 6 mm indentation
+4 = 8 mm indentation
Test for Ankle Clonus – support the leg with knee flexed… with one hand the examiner sharply dorsiflexes the foot, maintains the position for a
moment then releases the foot. Normal response is elicited when no rhythmic oscillations are felt while the foot is held in dorsiflexion.
Interventions – Mild Gestational HTN & Preeclampsia w/o Severe features
Goals of therapy are to ensure maternal safety and to deliver a healthy newborn as close to term as possible
Close monitoring of the maternal and fetal status
Can be managed at home if:
o BP less than 150/100 mmHg
o No increase in proteinuria
o Normal platelet count
o Normal liver enzymes
Mom needs to be well educated (See Teaching for Self-Management: Assessing and Reporting Clinical Signs of Preeclampsia)
Initial maternal labs: serum creatinine, platelet count, liver enzymes, 24-hr urine
Weekly labs: platelet count, liver enzymes
Also evaluated weekly for s/s of severe features: severe HAs, blurred vision, mental confusion, RUQ or epigastric pain, N/V, SOB,
decreased UO
BP monitored twice/week
Proteinuria assessed weekly
Daily fetal movement counts
NST or BPP 1x or 2x/week until birth
US evaluation of amniotic fluid status and estimated fetal weight at the time preeclampsia is dx and serially thereafter
Restricted activity may be recommended
Gentle exercise
Relaxation techniques
Regular diet
Protein (60-70 g)
Calcium (1200 mg)
Folic acid (600 mcg)
Zinc (11-12 mg)
Sodium (1.5 g)
Fluid intake (6-8 8oz glasses of H20)
Avoid alcohol and tobacco; limit caffeine
Severe Gestational HTN and Preeclampsia with Severe Features
Hospitalized immediately for a thorough evaluation of maternal-fetal status
Magnesium Sulfate (prevent eclamptic seizure)
Maternal assessment- monitoring BP, UO, cerebral status, epigastric pain, labor, vaginal bleeding
Maternal labs – platelet count, liver enzymes, serum creatinine
Continuous EFM
BPP
US (fetal growth & amniotic fluid)
Multidisciplinary plan of care
, 34 wks or greater, expedite birth after mom is stabilized (risks of continuing the pregnancy are considered greater than the risks of preterm
birth)
Less than 34 wks and no indication for giving birth immediately are candidates for expectant management
Expectant management: hospitalization, consult with perinatologist, oral antihypertensive meds, ongoing maternal and fetal assessments,
betamethasone
Intrapartum Care
o Continuous EFM
o CNS, Cardiovascular, Pulmonary, Hepatic, and Renal Systems Assessments/Evaluations
o Education and Supportive Measures
o Bedrest (quiet, darkened environment)
o Emergency drugs (See BOX 27-3 p. 664), oxygen, and suction equipment readily available
o IVFs and oral fluids (125 ml/hr)
Magnesium Sulfate
Given to prevent or treat seizures
Initial loading dose 4-6 g in 100 ml IV fluid given over 15-30 minutes
Maintenance dose 1-3 g/hr (40 grams in 1000 ml LR)
Administer IVPB using infusion pump
Therapeutic level: serum Mg level between 4-7 mEq/L
Can also be given IM
o IM route rarely used. Painful injection, absorption rate uncontrolled, can cause tissue necrosis
o Give 10-g loading dose (5g in each buttock), hopefully with procaine using Z- track technique followed by massage
o Can repeat every 4 hours (5 g)
o Usually only given while patient is in transport to tertiary center
Magnesium Sulfate is a depressant
o CNS (check VS, level of consciousness, reflexes, headache, visual disturbances, lethargic)
o Cardiovascular – will feel flushed and hot – systemic vasodilatation
o Musculoskeletal – feels “heavy” and difficult to move extremities easily
o GI – slower emptying of stomach, decreased bowel motility
Prevent toxicity by careful monitoring patient’s condition. At least hourly:
o Assess BP and respirations
o Assess DTRs and clonus
o Urine output
o LOC, HA, visual disturbances, epigastric pain
o Fetal heart rate and activity
Mild Signs of Toxicity Lethargy, muscle weakness, decreased/absent DTRs, double vision, slurred speech
Increased Toxicity Hypotension, bradycardia, bradypnea, cardiac arrest
If toxicity occurs, stop infusion, give Calcium Gluconate (10 ml of a 10% solution IVP slowly over 3 minutes to avoid dysrhythmias,
bradycardia, and ventricular fibrillation)
Magnesium Sulfate is not considered toxic to healthy fetus of normal weight but if toxicity in mother occurs, infant may be born with
hyporeflexia, bradypnea, etc. Treat infant with calcium transfusions, assisted mechanical ventilation, etc. as needed
Contraindicated for women with myasthenia gravis (can cause respiratory failure), women with heart block, myocardial insufficiency and
renal disease
Excreted via kidneys so decreased urinary output may lead to toxic levels of Magnesium Sulfate
Control of BP
Antihypertensive meds if SBP >160 mmHg or DBP >110 mmHg
Hydralazine (Apresoline)
Labetalol (Trandate)
Nifedipine (Procardia)
Methyldopa
Postpartum Care
VS, I&Os, DTRs, LOC, HA, visual disturbances, epigastric pain
Magnesium Sulfate 12-24 hrs
S/S of preeclampsia usually resolve within 48hrs after birth
May need to administer antihypertensive medication
Evaluate blood loss carefully – Methergine contraindicated
Magnesium Sulfate potentiates action of narcotics and CNS depressants and calcium-channel blockers
May need additional support for patient and family
Encourage early prenatal care with subsequent pregnancy
Eclampsia
May be preceded by premonitory signs/symptoms or may come suddenly, without warning
Tonic contraction of all body muscles precedes the tonic-clonic convulsion
