Gestational_Hypertension_and_Preeclampsia_ACOG_Practice 2020

ACOG Practice Bulletin No. 222 Overview

  • Issued by the American College of Obstetricians and Gynecologists (ACOG)

  • Updates clinical management guidelines for obstetrician-gynecologists regarding gestational hypertension and preeclampsia.

  • Committee on Practice Bulletins collaborated on the update.

Introduction to Gestational Hypertension and Preeclampsia

  • Prevalence: Affects 2-8% of pregnancies globally; major cause of maternal and perinatal mortality.

    • In Latin America and the Caribbean, 26% of maternal deaths are attributed to these disorders.

    • In the U.S., preeclampsia rates grew by 25% from 1987 to 2004.

  • Economic Impact: The estimated cost of preeclampsia in the U.S. for the first year postpartum was $2.18 billion in 2012.

Risk Factors

  • Risk Factors List (Box 1):

    • Nulliparity, multifetal gestations, prior preeclampsia, chronic hypertension, pregestational diabetes, gestational diabetes, thrombophilia, autoimmune diseases, body mass index over 30, maternal age over 35 years, kidney disease, assisted reproductive technology, obstructive sleep apnea.

  • Most cases occur in healthy nulliparous women with no obvious risk factors.

  • Genetic-environmental interactions are suspected to influence risk.

Definitions and Diagnostic Criteria

Preeclampsia

  • Defined as new-onset hypertension after 20 weeks of gestation, often with proteinuria.

  • Symptoms may present without proteinuria (e.g., elevated liver enzymes, severe headaches).

  • Diagnostic criteria include blood pressure and additional features (Box 2).

    • Severe features include: Thrombocytopenia, elevated liver enzymes, severe right upper quadrant pain, renal insufficiency, pulmonary edema, and non-responsive headache.

Gestational Hypertension

  • Diagnosed when systolic BP is ≥ 140 mm Hg or diastolic BP is ≥ 90 mm Hg on two occasions.

  • Classified as severe if systolic BP ≥ 160 mm Hg or diastolic BP ≥ 110 mm Hg.

Clinical Presentation and Preeclampsia Types

HELLP Syndrome

  • One of the severe forms of preeclampsia characterized by hemolysis, elevated liver enzymes, and low platelet count.

  • Associated with significant maternal morbidity and mortality.

Eclampsia

  • Defined by new-onset seizures in pregnant women, occurring in conjunction with hypertensive disorders.

  • Can cause severe complications such as traumatic injury, aspiration pneumonia, and is a significant cause of maternal death.

Pathophysiology of Preeclampsia

  • Theories suggest several mechanisms, including:

    • Chronic uteroplacental ischemia, immune maladaptation, very low-density lipoprotein toxicity.

  • Angiogenic factors' imbalances may contribute to preeclampsia's development.

Management Strategies

Screening and Prevention

  • Limited predictive value for screening low-risk women; false positives are common.

  • Aspirin (81 mg/day) recommended for high-risk women starting between 12-28 weeks.

  • Calcium supplementation may reduce preeclampsia risk in women with low baseline intake.

Treatment for Severe Hypertension

  • Antihypertensive treatment commenced for acute hypertension (systolic ≥160 mm Hg or diastolic ≥110 mm Hg).

  • Magnesium sulfate administered for seizure prophylaxis in preeclampsia with severe features.

  • Management may depend on gestational age, risks, and stabilization of maternal condition.

Conclusion and Recommendations

  • Categorical recommendations including:

    • Low-dose aspirin for high-risk women.

    • Delivery recommended upon diagnosis of gestational hypertension or preeclampsia at or beyond 37 weeks.

    • Magnesium sulfate as preventative treatment during labor for patients with preeclampsia with severe features.

  • Emphasis on close maternal-fetal monitoring to manage ongoing risks associated with hypertensive disorders.