What are the clinical signs of preeclampsia in a pregnant woman during labor?

Clinical Signs of Preeclampsia During Labor

During labor, preeclampsia presents with hypertension (≥140/90 mmHg) accompanied by emergency symptoms including headache, visual disturbances, epigastric pain, neurological changes, or evidence of organ dysfunction—all requiring immediate recognition and treatment to prevent maternal mortality. 1

Key Clinical Presentations

Cardiovascular Signs

• Blood pressure ≥140/90 mmHg confirmed on at least two occasions 15 minutes apart, or ≥160/110 mmHg (severe hypertension requiring immediate treatment) 1
• Systolic BP >160 mmHg or diastolic BP >100 mmHg triggers maternal early warning criteria 1
• Heart rate <50 or >130 bpm indicates maternal compromise 1

Neurological Manifestations

• Severe, non-remitting headache in the context of hypertension—this is a disease-defining feature and should be considered preeclampsia until proven otherwise 1
• Visual disturbances including scotomata, blurred vision, or photophobia 1
• Altered mental status, maternal agitation, confusion, or unresponsiveness 1
• Brisk reflexes or hyperreflexia with clonus, though this is nonspecific and subject to observer interpretation 1
• Papilledema on examination 1

Gastrointestinal and Hepatic Signs

• Epigastric or right upper quadrant pain suggesting hepatic capsular distension and risk of rupture 1
• Nausea, vomiting, or anorexia 1
• Hepatic tenderness on palpation 1

Respiratory Signs

• Shortness of breath or dyspnea 1
• Oxygen saturation <95% on room air at sea level 1
• Signs of pulmonary edema suggesting heart failure or severe preeclampsia (occurs in 30% of patients with pre-existing heart disease and preeclampsia) 1

Renal Signs

• Proteinuria (≥1+ on dipstick, ACR ≥30 mg/mmol, or >0.3 g/24h), though notably proteinuria is present in only ~75% of preeclampsia cases and is not required for diagnosis 1
• Oliguria (<35 mL/h for ≥2 hours) 1

Laboratory Evidence of Organ Dysfunction

While not "clinical signs" per se, these should be assessed urgently during labor:

• Thrombocytopenia (platelets <100,000/μL) 1
• Elevated liver enzymes (AST, ALT, LDH) indicating hepatocellular injury 1
• Elevated serum creatinine indicating acute kidney injury 1
• Hemolysis (elevated LDH, decreased haptoglobin) 1

Critical Pitfalls to Avoid

Blood pressure alone does not reliably stratify risk—serious organ dysfunction can develop at relatively mild hypertension levels (140-159/90-109 mmHg), so the presence of any symptoms or signs of end-organ damage mandates urgent evaluation regardless of BP severity 2.

Do not wait for proteinuria to diagnose preeclampsia—the diagnosis requires hypertension plus any one of: proteinuria, maternal organ dysfunction (renal, hepatic, neurological, hematological), or uteroplacental dysfunction 1. Approximately 25% of preeclampsia cases lack proteinuria 1.

Hyperreflexia is nonspecific—while brisk reflexes occur in many women with preeclampsia, this finding is also present in healthy young women and should not be used as a sole diagnostic criterion 1.

Preeclampsia can present postpartum—up to 10% of maternal deaths from hypertensive disorders occur postpartum, with most cases presenting within 7-10 days after delivery, often with neurological symptoms 1, 3, 4.

Immediate Management Priorities

When clinical signs suggest preeclampsia during labor:

• Initiate antihypertensive therapy if BP ≥160/110 mmHg with IV labetalol or oral nifedipine, targeting SBP 140-150 mmHg and DBP 90-100 mmHg (mean BP reduction of 15-25%) 1
• Administer magnesium sulfate for seizure prophylaxis if severe hypertension, neurological symptoms, or other severe features are present 5, 2, 6
• Obtain urgent laboratory workup: complete blood count (hemoglobin, platelets), liver enzymes (AST, ALT, LDH), renal function (creatinine, uric acid), coagulation studies 1
• Plan for delivery—this is the only definitive treatment, with timing based on gestational age and severity of maternal/fetal condition 5, 2