Preeclampsia Diagnosis and Management

Diagnostic Criteria

The European Society of Cardiology defines preeclampsia as gestational hypertension (≥140/90 mmHg) that appears after 20 weeks of gestation, accompanied by one or more of the following: proteinuria, maternal organ dysfunction, or uteroplacental dysfunction 1, 2
The American College of Cardiology recommends that systolic blood pressure ≥140 mmHg and/or diastolic blood pressure ≥90 mmHg be confirmed in two separate occasions or at least 15 minutes apart in cases of severe hypertension (≥160/110 mmHg) 2
Hypertension must appear after 20 weeks of gestation in previously normotensive women, according to the European Heart Journal 1, 3
Significant proteinuria is defined as >0.3 g/24h or albumin-creatinine ratio ≥30 mg/mmol, as recommended by the European Heart Journal 1
A positive dipstick test (≥1+) should prompt immediate evaluation using albumin-creatinine ratio in a single sample or 24-hour urine collection, according to the European Heart Journal 1
An albumin-creatinine ratio <30 mg/mmol reliably excludes proteinuria in pregnancy, as stated by the European Heart Journal 1

Alternative Diagnostic Criteria

In the absence of proteinuria, preeclampsia can be diagnosed when gestational hypertension is accompanied by one or more of the following: maternal organ dysfunction or uteroplacental dysfunction, as defined by the European Heart Journal 1, 2
Maternal organ dysfunction includes acute kidney injury, liver dysfunction (elevated transaminases), neurological complications (severe headache, visual disturbances, eclampsia), and pulmonary edema, according to the European Heart Journal 1
Uteroplacental dysfunction includes fetal growth restriction, abnormal umbilical artery Doppler waveform analysis, and intrauterine fetal death, as defined by the European Heart Journal 1

Biomarkers

A sFlt-1/PlGF ratio ≤38 can be used to exclude the development of preeclampsia in the following week when clinically suspected, as recommended by the European Heart Journal 1

Risk Factors

Significant risk factors include the presence of antiphospholipid antibodies (RR 9.72), previous history of preeclampsia (RR 7.19), pre-existing diabetes (RR 3.56), multiple pregnancy (RR 2.93), nulliparity (RR 2.91), family history of preeclampsia (RR 2.90), age ≥40 years (RR 1.68-1.96), and high BMI at the start of pregnancy (RR 1.55), as reported by the BMJ 3, 4

Differential Diagnosis

The differential diagnosis should include gestational hypertension without proteinuria, chronic hypertension, and preeclampsia superimposed on chronic hypertension, as stated by the European Heart Journal 1, 2
Hypertension that appears before 20 weeks typically represents pre-existing or chronic hypertension, not preeclampsia, according to Praxis Medical Insights 5

Diagnostic Criteria and Management of Pre-eclampsia

Diagnostic Considerations

The American College of Cardiology recommends that maternal organ dysfunction, such as renal dysfunction (serum creatinine ≥1.1 mg/dL or doubling of baseline), hepatic dysfunction (elevated liver transaminases ≥2 times upper limit of normal), hematological dysfunction (thrombocytopenia <100,000/microliter), be considered in the diagnosis of pre-eclampsia 6
Proteinuria is present in approximately 75% of pre-eclampsia cases, but is not required for diagnosis 6

Monitoring and Assessment

The American Heart Association recommends that all women with suspected pre-eclampsia should have a full blood count, liver enzymes, serum creatinine, electrolytes, uric acid, urinalysis, and protein quantification 6
Blood pressure monitoring should be performed regularly, with values consistently ≥140/90 mmHg requiring treatment, and urgent treatment in a monitored setting is required when BP ≥160/110 mmHg 7

Classification of Severity

The American College of Cardiology recommends that preeclampsia with severe features includes severe hypertension (≥160/110 mmHg) despite treatment with multiple antihypertensives, progressive thrombocytopenia, progressive abnormal renal or liver enzyme tests, pulmonary edema, neurological complications, and non-reassuring fetal status 7

Differential Diagnosis and Common Pitfalls

The American Heart Association recommends that neither serum uric acid nor the level of proteinuria should be used as an indication for delivery, and hyper-reflexia is a nonspecific finding often present in otherwise healthy young women and is no longer recommended as a diagnostic criterion 6, 7

Pre-eclampsia Diagnosis and Management

Assessment and Monitoring

The British Medical Journal recommends that all women should be assessed for pre-eclampsia risk factors at the first antenatal visit and after 20 weeks' gestation, women should be assessed for signs and symptoms of pre-eclampsia at every antenatal visit, including blood pressure measurement, urinalysis for proteinuria, evaluation for symptoms, and assessment of fetal well-being 8
Women with risk factors should be seen at least once every three weeks before 32 weeks, and then at least once every two weeks until delivery, while women with no risk factors should follow local protocols for antenatal care but should be informed about pre-eclampsia symptoms and how to contact healthcare professionals at all times 8, 9

Actions Based on Findings

The British Medical Journal suggests that women with new hypertension without proteinuria should be referred for hospital assessment within 48 hours if diastolic BP is ≥90 and <100 mmHg, and for same-day hospital assessment if diastolic BP is ≥100 mmHg or systolic BP is ≥160 mmHg 8, 9
Women with new hypertension with proteinuria should be referred for same-day hospital assessment if diastolic BP is ≥90 mmHg and proteinuria is ≥+ on dipstick, and should arrange immediate admission if diastolic BP is ≥110 mmHg and proteinuria is ≥+ on dipstick or if systolic BP is ≥170 mmHg and proteinuria is ≥+ on dipstick 8, 9

Prognosis and Complications

Pre-eclampsia can progress to a life-threatening situation in approximately two weeks from diagnosis, requiring close monitoring 8, 10

Pre-eclampsia Diagnostic Considerations

Diagnostic Criteria and Pitfalls

Edema is not predictive and should not be used diagnostically, as noted by the British Medical Journal 11
Eclampsia can occur without severe hypertension, with 34% of eclamptic women having a maximum diastolic BP ≤100 mmHg, according to the British Medical Journal 11

Timing and Risk Considerations

New hypertension before 32 weeks carries a 50% chance of developing pre-eclampsia, as reported by the British Medical Journal 11
New hypertension at 24-28 weeks is particularly predictive of severe pre-eclampsia, also noted by the British Medical Journal 11

ISSHP Diagnostic Criteria for Eclampsia

Hypertension Requirement

The International Society for the Study of Hypertension in Pregnancy (ISSHP) states that new‑onset hypertension after 20 weeks’ gestation is a mandatory component for diagnosing preeclampsia, and therefore eclampsia (seizures occurring in the setting of preeclampsia). 12
Although ISSHP acknowledges that preeclampsia may occasionally occur without overt hypertension, the current guideline recommendation retains hypertension as an essential diagnostic element. 13, 14

Proteinuria Not Mandatory

ISSHP specifies that proteinuria is not required for the diagnosis of preeclampsia or eclampsia; it is present in only about 75 % of preeclampsia cases. 12, 13

Organ Dysfunction as Diagnostic Criterion

In addition to hypertension, ISSHP allows a diagnosis of preeclampsia/eclampsia when any maternal organ dysfunction is documented, such as thrombocytopenia (platelet count < 100 × 10⁹/L). This laboratory abnormality is explicitly listed in the ISSHP criteria. 13

Immediate Clinical Assessment Recommendations

When a pregnant woman presents with seizures after 20 weeks’ gestation, the ISSHP‑based algorithm advises measuring blood pressure without delay; even mild elevation (≥140/90 mmHg) should prompt suspicion for eclampsia. 12

Detailed Risk Assessment and Monitoring Guidelines for Preeclampsia

Universal Blood‑Pressure Screening

All pregnant individuals should have their blood pressure measured at every prenatal visit to reduce maternal and perinatal morbidity and mortality. The sphygmomanometer is the recommended device, and measurements must be taken after the patient rests for 5 minutes, seated with back support, legs uncrossed, arm at heart level, and using an appropriately sized cuff (≥33 cm arm circumference). 15

High‑Impact Maternal Risk Factors (Relative Risk > 3.0)

Presence of antiphospholipid antibodies confers a very high risk of preeclampsia (RR ≈ 9.7; 95 % CI 4.3–21.8) and warrants specialist referral before 20 weeks’ gestation. [16][17]
A prior history of preeclampsia markedly increases risk (RR ≈ 7.2; 95 % CI 5.9–8.8); early specialist input is recommended. [16][17]
Pre‑existing diabetes (type 1 or type 2) raises the risk (RR ≈ 3.6; 95 % CI 2.5–5.0) and should trigger referral before 20 weeks. [16][17]
Multiple gestation is associated with higher risk (RR ≈ 2.9; 95 % CI 2.0–4.2) and also requires early specialist referral. [16][17]

Moderate‑Impact Risk Factors (Relative Risk ≈ 2.0–3.0)

Nulliparity increases the risk of preeclampsia (RR ≈ 2.9; 95 % CI 1.3–6.6). [16][17]
A first‑degree family history (mother or sister) of preeclampsia raises risk (RR ≈ 2.9; 95 % CI 1.7–4.9). [16][17]

Additional Significant Risk Factors

Maternal age ≥ 40 years modestly raises risk (RR ≈ 1.7 for nulliparous and ≈ 2.0 for multiparous women). [16][15]
Elevated pre‑pregnancy body‑mass index (BMI) confers increased risk (RR ≈ 1.55; 95 % CI 1.28–1.88); BMI ≥ 35 kg/m² is considered a significant risk marker. [16][15]
Pre‑existing chronic hypertension or diastolic BP ≥ 90 mm Hg at booking requires specialist referral before 20 weeks. [16][17]
Pre‑existing renal disease or proteinuria (≥ + on dipstick on ≥ two occasions or ≥ 300 mg/24 h) also mandates early referral. [16][17]
Inter‑pregnancy interval ≥ 10 years is listed as a risk factor. [16][17]

Mandatory Early Specialist Referral (Before 20 Weeks)

Women who have any of the high‑impact risk factors listed above (antiphospholipid antibodies, prior preeclampsia, pre‑existing diabetes, multiple gestation) or any two moderate‑impact risk factors should be offered specialist input before 20 weeks’ gestation. [16][17]

Post‑20‑Week Monitoring Pathways

Low‑Risk Group

Defined as pregnant individuals without any of the above risk factors; follow local protocols and NICE guidance for low‑risk monitoring. [16][17]

Elevated‑Risk Group

Defined as those with a single predisposing risk factor but no factor that mandates early referral.
Monitoring frequency:
- Between 24–32 weeks’ gestation, assessments should occur at intervals no longer than three weeks, individualized to patient needs. [16][17]
- From 32 weeks until delivery, assessments should occur at intervals no longer than two weeks, individualized to patient needs. [16][17]

Clinical Surveillance at Each Visit (After 20 Weeks)

Screen for new hypertension (≥ 140/90 mm Hg). [16][17]
Screen for new proteinuria (≥ + on dipstick, protein/creatinine ratio ≥ 30 mg/mmol, or ≥ 300 mg/24 h). [16][17]
Assess for headache, visual disturbances, epigastric pain, vomiting, reduced fetal movements, or fetal growth restriction. [16][17]

Urgent Referral Criteria (After 20 Weeks)

New hypertension without proteinuria:
- Diastolic 90–99 mm Hg → hospital evaluation within 48 h.
- Diastolic ≥ 100 mm Hg or systolic ≥ 160 mm Hg → same‑day hospital evaluation.
New hypertension with proteinuria:
- Diastolic ≥ 90 mm Hg with proteinuria ≥ + → same‑day evaluation.
- Diastolic ≥ 110 mm Hg or systolic ≥ 170 mm Hg with proteinuria ≥ + → immediate admission. [16][17] (Note: specific thresholds are derived from the cited guidelines.)

High‑Risk Surveillance and Prophylaxis for Nulliparous Women with a First‑Degree Family History of Severe Preeclampsia

Risk Assessment

A first‑degree family history of severe preeclampsia confers a moderate relative risk of 2.9 (95 % CI 1.7–4.9) for developing the condition. 18
Nulliparity adds an additional moderate relative risk of 2.9 (95 % CI 1.3–6.6) for preeclampsia. 19
The presence of any single moderate‑risk factor (e.g., family history or nulliparity) is sufficient to recommend low‑dose aspirin prophylaxis according to the latest international guidelines. 18

Blood‑Pressure Measurement Technique

Baseline blood‑pressure should be measured with the patient seated, back supported, legs uncrossed, arm at heart level, after 5 minutes of rest, using an appropriately sized cuff (arm circumference ≥ 33 cm requires a larger cuff). [19][20]
A diastolic pressure ≥ 80 mm Hg at the first prenatal visit identifies an elevated risk and triggers intensified monitoring. 21

Pharmacologic Prophylaxis

Low‑dose aspirin (75–150 mg daily) should be started before 16 weeks gestation (ideally before 12 weeks, but no later than 20 weeks). 18
Recommended aspirin dose varies by guideline: 75 mg (WHO, Ireland), 81 mg (U.S.), 100–150 mg (ESC, NICE, other European societies). 18
Aspirin therapy should be continued until delivery (or at least until 36–37 weeks gestation according to several guidelines). 18
If dietary calcium intake is < 600 mg/day, prescribe 1.2–2.5 g elemental calcium daily. 18

Monitoring Schedule

20–32 weeks gestation: clinic visits every ≤ 3 weeks (interval individualized). 21
> 32 weeks gestation: clinic visits every ≤ 2 weeks (interval individualized). 21
At each visit assess: standardized blood‑pressure, urine protein (dipstick ≥ 1+ confirmed with albumin/creatinine ratio or 24‑h collection), headache, visual disturbances, epigastric pain, vomiting, edema (recognizing it is not diagnostic), fetal movements, and fetal growth. 21

Specialist Referral

Early specialist referral before 20 weeks is not required when the only risk factors are nulliparity and a family history of severe preeclampsia. 21
Referral before 20 weeks is reserved for women with higher‑risk profiles (previous preeclampsia, antiphospholipid antibodies, pre‑gestational diabetes, chronic hypertension, renal disease, multiple gestation, or ≥ 2 moderate‑risk factors). 21

Patient Education

Counsel patients to seek urgent care for any of the following alarm symptoms: persistent severe headache, visual changes (scotoma, blurred vision), intense epigastric or right‑upper‑quadrant pain, persistent vomiting, or a sudden decrease in fetal movements. 21
Provide 24‑hour obstetric contact information for rapid access to care. 21

Quality Assurance

Any elevated blood‑pressure reading should be re‑measured during the same visit before making clinical decisions. 20
Initiation of aspirin before 16 weeks maximizes its preventive efficacy for preeclampsia. 18

Excessive Gestational Weight Gain and Associated Maternal‑Fetal Risks

Maternal Complications

Rapid weight gain of 3–4 kg per month (≈12–16 kg per trimester) markedly increases the risk of gestational hypertension, pre‑eclampsia, and gestational diabetes compared with guideline‑recommended weight‑gain targets. 22, 23, 24, 25

Fetal Outcomes

Women with this pattern of excessive weight gain have a higher likelihood of delivering large‑for‑gestational‑age (macrosomic) infants. 22, 23

Screening Recommendations

If a pregnant woman exhibits rapid monthly weight gain and has not yet been screened for gestational diabetes, a 75‑g oral glucose tolerance test (OGTT) should be performed promptly. 24

Diagnostic Criteria and Management of Preeclampsia Without Severe Features

Blood Pressure Requirements

New‑onset hypertension defined as systolic ≥ 140 mmHg and/or diastolic ≥ 90 mmHg after 20 weeks’ gestation in a previously normotensive woman, confirmed on at least two separate readings (≥15 min apart for severe‑range thresholds or over several hours for non‑severe ranges)【26】.
For non‑severe hypertension (140‑159/90‑109 mmHg), repeat measurements over several hours are required before clinical decisions are made【26】.

Proteinuria Assessment

Proteinuria is not mandatory for diagnosis; when measured, the threshold is ≥0.3 g per 24 h or a spot urine protein/creatinine ratio ≥30 mg/mmol (≈0.3 mg/mg)【26】.
A dipstick result of ≥1+ (≈30 mg/dL) should trigger quantitative testing with a protein/creatinine ratio【26】.
The absolute amount of proteinuria does not predict maternal severity nor dictate delivery timing; even massive proteinuria (>5 g/24 h) only correlates with neonatal outcomes【26】.

Measurement Technique Recommendations

Preferred devices are liquid‑crystal sphygmomanometers; if unavailable, validated automated monitors that have been specifically tested in preeclampsia populations should be used【26】.
Aneroid sphygmomanometers require regular calibration because they can be inaccurate in up to 50 % of cases【26】.

Clinical Pitfalls and Non‑Diagnostic Findings

Peripheral edema is a nonspecific sign and should not be used as a diagnostic criterion for preeclampsia【27】.

Prognostic Indicators and Risk of Progression

Eclampsia may occur without severe hypertension: in a UK cohort, 34 % of women who developed eclampsia had a maximum diastolic pressure ≤100 mmHg【27】.
Early‑onset hypertension (before 32 weeks) confers a ~50 % chance of evolving into preeclampsia; hypertension identified at 24‑28 weeks is especially predictive of subsequent severe disease【27】.
After a diagnosis of preeclampsia without severe features, life‑threatening complications can develop within approximately 2 weeks, underscoring the need for close surveillance【27】.