Should a 41‑year‑old woman at 25 weeks gestation who experienced brief visual flashes be evaluated for hypertension or preeclampsia?

Yes, She Should Be Evaluated Promptly for Preeclampsia

This 41-year-old woman at 25 weeks gestation with new visual symptoms (light flashes) requires same-day evaluation for preeclampsia, regardless of whether she has documented hypertension. Visual disturbances—including photopsia (light flashes), scotomata, or blurred vision—are recognized as symptoms of severe preeclampsia and warrant urgent assessment 1.

Why Visual Symptoms Alone Demand Evaluation

The guidelines are clear that preeclampsia can present with visual or neurological symptoms even before hypertension or proteinuria are documented 2. According to the 2018 ISSHP guidelines, preeclampsia is now diagnosed by new-onset hypertension (≥140/90 mmHg) after 20 weeks plus any of the following:

• Proteinuria
• Visual disturbances (including photopsia)
• Headache
• Thrombocytopenia
• Elevated liver enzymes
• Renal insufficiency
• Pulmonary edema

Proteinuria is no longer required for diagnosis 2. Visual symptoms in the context of pregnancy after 20 weeks are a red flag for cerebral edema associated with preeclampsia 1.

Immediate Action Required

According to the PRECOG guidelines, when a pregnant woman presents with maternal symptoms (headache, visual disturbances) without documented hypertension or proteinuria, she should:

• Have blood pressure checked immediately
• If BP is <90 mmHg diastolic with trace or no protein: Follow local protocols for investigation and consider reducing the interval before next assessment
• If any symptom is present with diastolic BP ≥90 mmHg: Refer for same-day hospital assessment 3

Even if her blood pressure appears normal in the office, she needs:

1. Repeated BP measurements to confirm true readings (office BP can miss transient elevations)
2. Urinalysis with dipstick followed by protein/creatinine ratio if positive
3. Laboratory evaluation: Complete blood count (platelets), liver enzymes (AST, ALT, LDH), serum creatinine, and uric acid 2
4. Clinical assessment for other symptoms: headache, right upper quadrant pain, hyperreflexia

Critical Context for This Patient

Several factors increase urgency:

• Advanced maternal age (41 years) is a recognized risk factor for preeclampsia 4
• 25 weeks gestation means she's in the window where early-onset preeclampsia carries the highest maternal and fetal risks 1, 3
• Visual symptoms specifically indicate potential cerebral involvement, which can progress rapidly to eclampsia 1

The ESC guidelines explicitly list "headache + visual disturbance (cerebral oedema)" and "occipital lobe blindness" as symptoms of severe preeclampsia 1. While brief photopsia lasting only 2 seconds may seem minor, it represents a neurological symptom that cannot be dismissed in a pregnant woman after 20 weeks.

Common Pitfall to Avoid

Do not wait for hypertension or proteinuria to develop before taking action. The 2018 ISSHP guidelines emphasize that preeclampsia can present with organ dysfunction (including visual symptoms) before BP rises to diagnostic thresholds 2. Women with "gestational proteinuria" or isolated symptoms may represent early preeclampsia that hasn't fully declared itself yet 2.

Additionally, the physiological BP decrease in early pregnancy can mask pre-existing hypertension, meaning her "normal" first-trimester readings may not reflect her true baseline 1.

What Evaluation Will Accomplish

If preeclampsia is confirmed, management depends on severity:

• Without severe features at 25 weeks: Twice-weekly BP monitoring, serial labs, antenatal fetal testing, with delivery planned at 37 weeks 2, 5
• With severe features (persistent visual symptoms, BP ≥160/110, abnormal labs): Hospitalization, magnesium sulfate for seizure prophylaxis, antihypertensive therapy, corticosteroids for fetal lung maturity, and consideration of delivery depending on maternal/fetal status 2, 5, 6

The retinal complications described in recent case reports—including serous retinal detachment and retinal artery occlusion—can occur with preeclampsia and typically resolve after delivery, but require ophthalmologic evaluation if symptoms persist 7, 8, 9, 10.

Bottom line: Arrange same-day obstetric evaluation with BP measurement, urinalysis, and laboratory testing. Visual symptoms in pregnancy after 20 weeks are preeclampsia until proven otherwise.