Definition

In 2000 the National High Blood Pressure Education Program proposed four categories of hypertension associated with pregnancy, a categorization that has gained widespread acceptance. The Task Force on Hypertension in Pregnancy of the American College of Obstetricians and Gynecologists (ACOG) updated the content of the classification in 2013 and retained nearly the same four categories: gestational hypertension, preeclampsia (with and without severe features), chronic hypertension, and chronic hypertension with superimposed preeclampsia ( Box 10.1 ).

Gestational hypertension occurs with elevated BPs after 20 weeks’ gestation without other diagnostic features of preeclampsia. Preeclampsia occurs with and without severe features and is typically diagnosed by BPs greater than or equal to 140/90 mm Hg with proteinuria ( Table 10.1 ). Preeclampsia with severe features is characterized by severe range BPs with or without other maternal organ dysfunction (see Table 10.1 ). Eclampsia is defined as the occurrence of seizures unrelated to a preexisting neurologic disorder that occur in women who are preeclamptic. Chronic hypertension is diagnosed with a BP greater than or equal to 140/90 mm Hg before 20 weeks’ gestation or after 12 weeks following delivery. Chronic hypertension with superimposed preeclampsia is diagnosed with new-onset proteinuria, a marked increase of preexisting proteinuria or BP, or when other symptoms of organ dysfunction are noted. The HELLP syndrome is characterized by the presence of intravascular hemolysis, elevated liver enzymes (most often alanine aminotransferase [ALT] and/or aspartate aminotransferase [AST]), and low platelet count; it usually manifests earlier during pregnancy compared with other types of preeclampsia.

Recognition

Preeclampsia with severe features is defined when BP exceeds 160/100 mm Hg or the patient exhibits evidence of end-organ damage (see Table 10.1 ). Severe features can include the following:

• •
  

  Pulmonary edema.

  
  
• •
  

  Renal dysfunction. Although large proteinuria was previously used as a criterion for defining severe preeclampsia, recent work has not shown a significant relationship between the degree of proteinuria and pregnancy outcomes; therefore the degree of proteinuria has been dropped as a diagnostic feature for severe disease.

  
  
• •
  

  Cerebral manifestations, including headache, visual changes, or seizures.

  
  
• •
  

  Elevated liver enzymes with right upper quadrant pain (secondary to hepatic capsular distention).

  
  
• •
  

  Thrombocytopenia with a platelet count less than 100,000/mm ³ .

Intrauterine growth restriction, previously included, has been removed as a criterion.

The HELLP syndrome may occur with modest levels of BP elevation, and in 15% of cases BP can be normal. Diagnosis of preeclampsia in the parturient with preexisting chronic hypertension and renal disease can be very difficult; increases in urinary protein over time may be the only sign. It may be difficult to identify preeclampsia in parturients with acute cocaine intoxication, as both can present with seizures, pulmonary edema, proteinuria, and thrombocytopenia. However, the onset of seizures in women after 20 weeks’ gestation with an elevated BP should be considered eclampsia until proven otherwise. Preeclampsia with severe features can present up to 2 weeks postpartum.

Risk Assessment

Gestational hypertension occurs in approximately 5% of pregnancies, and 50% of women with gestational hypertension before 30 weeks of pregnancy develop preeclampsia. Preeclampsia occurs in approximately 6% to 8% of all pregnancies in the United States, 25% of which will go on to develop preeclampsia with severe features. It accounts for 25% of all maternal deaths in the United States.

Several risk factors are associated with the development of preeclampsia ( Box 10.2 ). Demographic factors, such as advanced maternal age and African American ethnicity, increase risk. Some obstetric conditions that increase its possibility are uterine overdistention (e.g., multiple gestations, polyhydramnios), trophoblastic disease, abnormal uterine artery Doppler studies obtained between 18 and 24 weeks’ gestation, and previous histories of preeclampsia and placental abruption. Preexisting maternal diseases, such as obesity, diabetes, chronic hypertension, and collagen vascular disorders, convey higher risk for preeclampsia as well.

BOX 10.2

Demographic Factors

• 
  

  Advanced maternal age (>35 yr)

  
  
• 
  

  African American race

Concurrent Maternal Disease

• 
  

  Obesity

  
  
• 
  

  Preexisting hypertension

  
  
• 
  

  Diabetes

  
  
• 
  

  Renal disease

  
  
• 
  

  Antiphospholipid antibody syndrome

  
  
• 
  

  Vascular or connective tissue disorder

  
  
• 
  

  Angiotensin gene T235

Obstetric Conditions/History

• 
  

  Multiple gestations

  
  
• 
  

  Polyhydramnios

  
  
• 
  

  Molar pregnancy

  
  
• 
  

  Previous history of preeclampsia

  
  
• 
  

  In vitro fertilization

  
  
• 
  

  Nulliparity

  
  
• 
  

  Previous history of placental abruption, fetal growth restriction

  
  
• 
  

  Partner who fathered a previously preeclamptic pregnancy

Risk Factors for Preeclampsia

Only gold members can continue reading. Log In or Register to continue

Share this:

• Click to share on Twitter (Opens in new window)
• Click to share on Facebook (Opens in new window)

Related

Related posts:

Chemical Dependency: Nonopioids Hyperthyroidism: Thyroid Storm Preanesthetic Evaluation: Inadequate or Missing Test Result Upper Respiratory Tract Infection Anticoagulation Initiation and Reversal for Cardiac Surgery Complications of Carcinoid Tumors

Stay updated, free articles. Join our Telegram channel

Join