Diagnosis and Management of Pre-eclampsia

Core Diagnostic Criteria

• The American College of Obstetricians and Gynecologists recommends that pre-eclampsia be diagnosed by new-onset hypertension (≥140/90 mmHg) occurring after 20 weeks of gestation combined with either proteinuria (≥300 mg/24h) or evidence of maternal organ dysfunction 1, 2
• Systolic BP ≥140 mmHg and/or diastolic BP ≥90 mmHg should be confirmed on two separate occasions at least 15 minutes apart, according to the American Heart Association 2
• Hypertension must be new-onset after 20 weeks of gestation in previously normotensive women, as stated by the National Institute for Health and Care Excellence 1, 2

Alternative Diagnostic Criteria

• When proteinuria is absent, pre-eclampsia can be diagnosed if gestational hypertension is accompanied by any one of the following maternal organ dysfunctions: renal dysfunction, hepatic dysfunction, hematological dysfunction, neurological complications, pulmonary complications, or uteroplacental dysfunction, according to the American College of Obstetricians and Gynecologists 2
• Renal dysfunction is defined as serum creatinine ≥1.1 mg/dL or doubling of baseline creatinine, as stated by the National Kidney Foundation 2

Screening and Assessment Protocol

• The American College of Obstetricians and Gynecologists recommends identifying women with predisposing factors, including first pregnancy, previous pre-eclampsia, ≥10 years since last baby, age ≥40 years, body mass index ≥35, family history of pre-eclampsia, booking diastolic blood pressure ≥80 mmHg, proteinuria at booking, multiple pregnancy, pre-existing diabetes, pre-existing hypertension or renal disease, and presence of antiphospholipid antibodies 3, 4, 5
• Women with one risk factor should be assessed at least every 3 weeks before 32 weeks, then every 2 weeks until delivery, according to the National Institute for Health and Care Excellence 3, 6, 7

Laboratory Evaluation

• When pre-eclampsia is suspected, obtain complete blood count, liver enzymes, serum creatinine and electrolytes, uric acid, and urinalysis with protein quantification, as recommended by the American College of Obstetricians and Gynecologists 2
• The sFlt-1/PlGF ratio ≤38 can exclude development of pre-eclampsia in the following week when clinically suspected, according to the National Institute for Health and Care Excellence 2

Severity Classification

• Pre-eclampsia with severe features includes severe hypertension, progressive thrombocytopenia, progressive abnormal renal function tests, progressive abnormal liver enzyme tests, pulmonary edema, neurological complications, and non-reassuring fetal status, as defined by the American College of Obstetricians and Gynecologists 2

Referral Thresholds

• Diastolic BP ≥90 and <100 mmHg without proteinuria: refer for hospital assessment within 48 hours, according to the National Institute for Health and Care Excellence 6, 2
• Diastolic BP ≥90 and <100 mmHg with proteinuria ≥+ on dipstick: refer for same-day hospital assessment, as recommended by the American College of Obstetricians and Gynecologists 2

Postpartum Pre-eclampsia Diagnosis

• Postpartum pre-eclampsia is diagnosed by new-onset hypertension (≥140/90 mmHg) occurring 48 hours to 6 weeks after delivery with either proteinuria or maternal organ dysfunction, according to the American College of Obstetricians and Gynecologists 8
• Measure blood pressure at least every 4 hours while awake for at least 3 days postpartum, as recommended by the National Institute for Health and Care Excellence 8

Diagnosis of Pre‑eclampsia: Evidence‑Based Criteria and Screening

Proteinuria Assessment

• Dipstick proteinuria ≥ + on more than one occasion can be used as a diagnostic criterion for pre‑eclampsia. 9

Uteroplacental Dysfunction Indicators

• Patient‑reported reduction in fetal movements may indicate uteroplacental dysfunction and support a diagnosis of pre‑eclampsia. 9
• Identification of a small‑for‑gestational‑age fetus on ultrasound suggests uteroplacental dysfunction and can be used to diagnose pre‑eclampsia. 9

Antenatal Screening Protocol (≥ 20 weeks gestation)

• At every antenatal visit, blood pressure should be measured to detect new‑onset hypertension. 9
• At every antenatal visit, dipstick urinalysis should be performed to detect new‑onset proteinuria. 9
• At every antenatal visit, clinicians should inquire about persistent severe headache or visual disturbances as possible neurological signs of pre‑eclampsia. 9
• At every antenatal visit, assessment for severe or persistent right‑upper‑quadrant/epigastric pain or new‑onset vomiting should be undertaken as possible hepatic signs of pre‑eclampsia. 9
• At every antenatal visit, patients should be asked about reduced fetal movements as an indicator of possible uteroplacental compromise. 9
• At every antenatal visit, fetal growth should be evaluated; detection of a small‑for‑gestational‑age infant on ultrasound supports a diagnosis of pre‑eclampsia. 9
• A comprehensive screening protocol that includes blood pressure, proteinuria, neurological symptoms, hepatic symptoms, fetal movement assessment, and fetal growth evaluation is recommended for all pregnancies after 20 weeks gestation. 10