ACOG Preeclampsia Guidelines: Antenatal Management and Timing of Delivery

SUMMARY:

Recommendations for prenatal assessment and perinatal management, including delivery, are included in the ACOG preeclampsia and gestational hypertension guidelines.

Inpatient vs Outpatient Management

• Ambulatory management (outpatient) appropriate for the following
  • Gestational hypertension without severe features or
  • Preeclampsia without severe features
• Inpatient management appropriate for the following
  • Severe preeclampsia or
  • Poor adherence to monitoring recommendations

How to Measure BP

• Recommended technique for BP monitoring
  • Appropriate cuff size: 1.5 times upper arm circumference
  • Avoid tobacco or caffeine: Use in the 30 minutes preceding the measurement may lead to temporary rise in blood pressure
  • Patient should be upright after a 10-minute rest period
  • Inpatient setting: Measurement may be taken either
    • Sitting up or
    • Left lateral recumbent with arm at the level of the heart

Fetal and Maternal Assessment (Outpatient – No Severe Features)

Fetal Assessment

• Fetal growth assessment every 3-4 weeks
• Amniotic fluid assessment weekly
• Antenatal testing 1-2 times per week

Maternal Assessment

• Labs weekly (more frequently if concern that patient status is deteriorating)
  • Serum creatinine | Liver enzymes | Platelet count
  • Gestational hypertension: Include proteinuria
  • Note: If proteinuria is present, additional proteinuria measurements are not necessary
• Clinical evaluation: At least one visit per week in-clinic
  • Obtain BP and evaluate for severe features (see ‘Related ObG Topics’ below)
    • Combination ambulatory and in-clinic assessment
  • BP and symptom assessment are recommended “serially”, using a combination of in-clinic and ambulatory approaches, with at least one visit per week in-clinic
• sFlt-1/PlGF ratio to predict progression to preeclampsia with severe features
  • FDA approved | Studied in population of hospitalized patients between 23 and 35 weeks
  • ACOG states

There are insufficient data to recommend management strategies after a positive or negative test result

The sFlt-1:PlGF ratio alone should not replace current clinical criteria for diagnosing or excluding a diagnosis of preeclampsia with severe features

KEY POINTS:

Delivery vs Expectant Management

• Decision regarding management based on gestational age and results from the following evaluation
  • Maternal: CBC | Creatinine | LDH, AST, ALT | Proteinuria | Uric acid if superimposed preeclampsia suspected
  • Fetal: EFW | Amniotic fluid volume | Antenatal testing (BPP, NST)
• Candidate for expectant management
  • Gestational hypertension or preeclampsia without severe features <37w0d
  • Reassuring antenatal testing
  • Intact membranes
  • No vaginal bleeding
  • No evidence of active preterm labor
  • Note: Delivery at 37w0d | HYPITAT trial showed no benefit to expectant management beyond 37 weeks
• Candidate for delivery (expectant management not advised)
  • Severe range hypertension unresponsive to antihypertensive agent(s)
  • Persistent headache or persistent RUQ/epigastric pain unresponsive to treatment
  • Visual disturbance or altered sensorium or motor deficit
  • Stroke or MI
  • HELLP syndrome
  • Worsening renal function (Cr above 1.1 or double the baseline)
  • Pulmonary edema
  • Eclampsia
  • Placental abruption or bleeding in the absence of placenta previa
  • Abnormal antenatal testing
  • Fetal demise
  • Fetal lethal anomaly or extreme prematurity
  • UA Doppler REDF
  • Note: Fetal growth restriction, if other fetal assessment parameters are within normal range, is not an indication for delivery

Expectant Management for Severe Preeclampsia

• Shared decision making: Consider risk/benefit
  • Expectant management for severe preeclampsia provides benefit to fetus/newborn but potential risk to mother
• Risks of expectant management in the presence of severe features
  • Pulmonary edema | MI | Stroke | ARDS | Coagulopathy | Renal failure | Retinal injury
• ≥34w0d: Delivery is recommended
  • Do not delay delivery to administer steroids in late preterm
• <34w0d: Expectant management for women who are clinically stable 
  • Associated with higher GA (on average 1-2 weeks) at delivery | Improved neonatal outcomes
  • “Low maternal risk” in studies
  • Requires close maternal and fetal monitoring with serial laboratory testing
    • Deliver if maternal or fetal status deteriorates
  • Corticosteroid administration is recommended
    • “May not always be advisable” to delay delivery when indicated to provide full steroid course

Learn More – Primary Sources:

ACOG Practice Bulletin 222: Gestational Hypertension and Preeclampsia

Pre-eclampsia: pathophysiology and clinical implications

FIGO: A literature review and best practice advice for second and third trimester risk stratification, monitoring, and management of pre-eclampsia

ACOG Clinical Practice Update: Biomarker Prediction of Preeclampsia With Severe Features

Locate a Maternal Fetal Medicine Specialist

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Emergency Treatment for Severe Hypertension in Pregnancy

Summary:

Severe hypertension can be a life-threatening event during pregnancy and requires special vigilance in the postpartum period, particularly following hospital discharge. The goal of treatment is to control hypertension and prevent seizures.  Uncontrolled hypertension can lead to heart failure, myocardial ischemia, renal injury and stroke.

When to Treat:

Urgently treat acute onset severe hypertension in pregnancy or postpartum period

• SBP ≥160 and and/or DBP ≥110 mm Hg persisting for 15 minutes
  • systolic BP a predictor of maternal morbidity/mortality

First Line Therapy:

Nifedipine

Hydralazine

Labetalol

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Immediate Release Oral Nifedipine

Onset

• 5 to 10 minutes

Administration

• 10 to 20 mg orally
• Repeat in 20 minutes if needed
• Then 10 to 20 mg every 2 to 6 hours
• Maximum dose: 180 mg

Medication Risks

• Maternal tachycardia and headaches

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IV Hydralazine

Onset

• 10 to 20 minutes

Administration

• IV
  • 5  to 10 mg IV (or IM)
  • Then 5 to 10 mg IV every 20 to 40 minutes
• Infusion
  • 0.5 to 10 mg/hr
• Maximum dose: 20 mg

Medication Risks 

• Maternal hypotension and headaches
• Abnormal FH tracings

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IV Labetalol

Onset

• 1 to 2 minutes

Administration 

• IV
  • 10 to 20 mg IV
  • Then 20 to 80 mg every 10 to 30 minutes
• Infusion
  • 1 to 2 mg/min
• Maximum dose: 300 mg

Medication Risks 

• Avoid in the following clinical settings
  • Asthma
  • Preexisting myocardial disease | Decompensated cardiac function | Heart block | Bradycardia

Note: ACOG states that “any of these agents can be used to treat acute severe hypertension in pregnancy” | An approach detailed in ACOG guidance uses “an initial regimen of labetalol at 200 mg orally every 12 hours and increase the dose up to 800 mg orally every 8–12 hours as needed (maximum total 2,400 mg/d). If the maximum dose is inadequate to achieve the desired blood pressure goal, or the dosage is limited by adverse effect, then short-acting oral nifedipine can be added gradually”

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Seizure Prophylaxis: Magnesium Sulfate

• Remains drug of choice for seizure prophylaxis
• Magnesium sulfate should not be used to reduce blood pressure
• See more on magnesium sulfate in ‘Related ObG Topics’

When to Use

• Severe features of preeclampsia
  • Administer to all women
• No severe features of preeclampsia and systolic BP > 140 and < 160 mm Hg or diastolic BP > 90 and < 110 mm Hg
  • There is no consensus on this matter as prophylaxis will reduce eclampsia but 1 in 100 to 129 women need to be treated and side effects (although not life threatening) will increase
  • ACOG states that the decision to use magnesium sulfate when severe features are not present should be the decision of the “physician or institution, considering patient values or preferences, and the unique risk-benefit trade-off of each strategy”

Delivery and Postpartum

• Vaginal delivery
  • Continue infusion 24 hours postpartum
• Cesarean
  • Begin infusion (if not yet running) before surgery and continue 24 hours postpartum
  • Discontinuing prior to operative vaginal birth or cesarean section to avoid uterine atony or anesthetic drug interactions is not recommended

Administration

• Loading dose of 4 to 6 g administered per infusion pump over 20 to 30 minutes (i.e., slowly) followed by a maintenance dose of 1 to 2 g per hour as a continuous intravenous infusion
• IM option if IV access limited
  • 10 g initially as a loading dose (5 g IM in each buttock) followed by 5 g every 4 hours
  • Mix with 1 mL xylocaine 2% to alleviate pain

Learn More – Primary Sources:

ACOG Practice Bulletin 222: Gestational Hypertension and Preeclampsia

ACOG II Severe Hypertension in Pregnancy Bundle

FIGO: A literature review and best practice advice for second and third trimester risk stratification, monitoring, and management of pre-eclampsia

Diagnosing Preeclampsia – Key Definitions and ACOG Guidelines

WHAT IS IT?

Preeclampsia is a pregnancy specific hypertensive disease with multi-system involvement. It usually occurs after 20 weeks of gestation and can be superimposed on another hypertensive disorder. While preeclampsia was historically defined by the new onset of hypertension in combination with proteinuria, some women will present with hypertension and multisystemic signs in the absence of proteinuria. The presence of multisystemic signs is an indication of disease severity.

SUMMARY:

Diagnostic Criteria

Blood Pressure Criteria

• Hypertension – systolic BP > 140 mm hg or diastolic BP > 90 mm hg or both
  • On two occasions at least 4 hours apart after 20 weeks gestations with previously normal BP
  • Considered ‘mild’ until diastolic BP > 110mm hg or systolic BP ≥160 mm Hg
• Severe Hypertension – systolic BP > 160 mm hg or diastolic BP > 110 mm hg or both
  • Can confirm using a short time interval (e.g., minutes) to facilitate timely antihypertensive therapy

Note: Gestational Hypertension

• ACOG defines gestational hypertension as “hypertension without proteinuria or severe features develops after 20 weeks of gestation and blood pressure levels return to normal in the postpartum period”
• Caution and close follow-up is warranted as up to a half of women with gestational hypertension will go on to manifest signs an symptoms consistent with preeclampsia
• Women with severe gestational hypertension, even in the absence of proteinuria should be managed similar to women with severe preeclampsia
• ACOG states

Women with gestational hypertension with severe range blood pressures (a systolic blood pressure of 160 mm Hg or higher, or diastolic blood pressure of 110 mm Hg or higher) should be diagnosed with preeclampsia with severe features.

Proteinuria Criteria

• 24 hour urine collection >300 mg protein or
• Single voided urine protein/creatinine ratio ≥0.3
• Dipstick reading of 2+ (use only if other quantitative methods not available)

Preeclampsia Definitions

Preeclampsia

• Hypertension and proteinuria or
• In absence of proteinuria, new-onset hypertension with the new onset of any of the following
  • Thrombocytopenia: Platelets <100 x 10⁹/L
  • Renal insufficiency: serum creatinine >1.1 mg/dl or doubling of serum creatinine in the absence of other renal disease
  • Impaired liver function: Elevated blood concentrations of liver transaminases to twice normal concentration
  • Pulmonary edema
  • Neuro: Unexplained new-onset headache unresponsive to medication (without an alternative diagnosis) or visual symptoms

Preeclampsia with severe features

• Preeclampsia diagnosis, above, with any of the following
  • Severe hypertension
    • On two occasions at least 4 hours apart while on bed rest (unless already on antihypertensive therapy)
  • Thrombocytopenia: Platelets <100 x 10⁹/L
  • Impaired liver function (without an alternative diagnosis): Elevated liver transaminases greater than twice upper limit of normal or severe persistent right upper quadrant or epigastric pain not responsive to medications
  • Progressive renal insufficiency: serum creatinine >1.1 mg/dl or doubling of serum creatinine in the absence of other renal disease
  • Pulmonary edema
  • Neuro: Unexplained new-onset headache unresponsive to medication (without an alternative diagnosis) or visual symptoms

Note: The following are not diagnostic criteria for the diagnosis of preeclampsia or preeclampsia with severe features

• Clinically evident edema
• Rapid weight gain
• Massive proteinuria
  • Does not qualify as a ‘severe feature’
• Fetal growth restriction
  • ACOG states that while it is important to monitor fetal status, FGR in the setting of all other fetal assessment being within normal limits (e.g., AFV, Doppler), expectant management ‘may be reasonable’ if mother and fetus appear stable and no other clinical indication is present that would indicate the need for early delivery
• Uric acid
  • Hyperuricemia in hypertensive pregnancy is not a diagnostic marker, but is an important finding as a risk factor for adverse maternal and fetal outcomes
    • Small for gestational age (SGA) infant
    • Prematurity
    • Risk for adverse maternal outcomes if include patients with preeclampsia and risks increase with increasing concentration of uric acid
  • May be warranted in the setting of ‘diagnostic dilemmas’ such as diagnosing superimposed preeclampsia in the setting of chronic hypertension

Learn More – Primary Sources

ACOG Practice Bulletin 222: Gestational Hypertension and Preeclampsia

National Partnership for Maternal Safety Consensus Bundle on Severe Hypertension During Pregnancy and the Postpartum Period

Plasma uric acid remains a marker of poor outcome in hypertensive pregnancy: a retrospective cohort study

Pre-eclampsia: pathophysiology and clinical implications