Pre-eclampsia is a pregnancy-specific disorder usually recognised after 20 weeks through new high blood pressure together with protein in the urine, maternal organ dysfunction, or evidence that the placenta is not supporting the pregnancy normally. It ranges from a condition managed with close outpatient surveillance to a medical emergency requiring admission and delivery.

Who is at increased risk?

Risk is higher after previous pre-eclampsia, particularly when it was early or severe; in chronic hypertension, kidney disease, diabetes, autoimmune disease, multifetal pregnancy, or certain first pregnancies. Risk assessment early in pregnancy can identify women who may benefit from preventive strategies such as low-dose aspirin, but treatment should be prescribed by the treating clinician after reviewing contraindications and timing.

What monitoring may include

Assessment can include repeated blood pressure measurement, urine protein, blood counts, liver and kidney tests, symptom review, fetal growth ultrasound, amniotic-fluid assessment, and Doppler studies. The purpose is not to repeat tests mechanically. It is to detect whether maternal disease or placental dysfunction is progressing and to decide whether continuing the pregnancy remains safer than delivery.

Warning signs

Severe or persistent headache, visual disturbance, severe pain below the ribs or in the upper abdomen, sudden marked swelling, chest pain, breathlessness, seizures, heavy bleeding, or reduced fetal movements needs urgent clinical assessment. A home blood pressure reading of 140/90 mmHg or higher should prompt contact with the maternity team; a severely elevated reading or serious symptoms requires urgent care.

The delivery decision

Delivery is the definitive way to end the pregnancy process driving pre-eclampsia, but timing depends on gestation, severity, maternal laboratory findings, blood pressure control, fetal condition, and available neonatal support. Before term, the team balances the maternal risk of waiting against the fetal consequences of prematurity. That decision is individual and can change quickly, which is why a documented escalation plan matters.

Prevention, with perspective

Can a plan change
the odds?

Sometimes, yes. But the useful answer includes who was studied, what changed, and what the finding means for you. Here is one important example.

ASPRE / 2017

Preterm pre-eclampsia

Affected pregnancies, % · Screen-selected high-risk singleton pregnancies · 1,620 with follow-up

Aspirin group13 / 798 pregnancies
1.6%
Placebo group35 / 822 pregnancies
4.3%

Outcome: pre-eclampsia leading to delivery before 37 weeks. Trial percentages are not your personal risk or Mediclinic outcomes.

About 3 feweraffected pregnancies per 100 in this trial

The trial compared clinician-prescribed aspirin with placebo in a specific high-risk group. The difference was statistically significant.

Adjusted odds ratio (95% confidence interval): 0.38 (0.20–0.74)

A conversation, not a prescription

Do not start, stop, or change aspirin from this chart. Your clinician should assess your history, bleeding risks, allergies, dose, and timing. Prevention does not replace monitoring.

Understand pre-eclampsia in depth
Study details and source

ASPRE randomized 1,776 participants. The primary outcome analysis included 798 in the aspirin group and 822 in the placebo group after withdrawals and loss to follow-up. Trial regimen: 150 mg daily from 11–14 until 36 weeks. This describes the research, not a universal treatment schedule.

Rolnik et al. · NEJM 2017 · DOI: 10.1056/NEJMoa1704559

Understand your baseline

Previous pregnancies, health conditions, medicines, and the current findings shape the plan.

Agree what to follow

Know which symptoms, measurements, blood tests, and scans matter in your situation.

Know when to call

Severe symptoms need urgent assessment. An online request is not an emergency service.

The essential distinctions

Mother, placenta, baby: one connected picture.

The placenta supports exchange between two separate circulations. Assessment looks at how the whole system is working.

  1. The placenta

    Transfers oxygen and nutrients, and removes waste. Its position and function are different questions.

  2. The baby

    Growth, movements, fluid, and Doppler help build a picture of wellbeing.

  3. The pregnancy

    Maternal health, membranes, and gestational age shape the next decision.

Read the supporting source ↗

Visual decision pathway

Suspected pre-eclampsia: assess, classify, act

Blood pressure is one part of the decision; symptoms, laboratory results, placental function and fetal condition complete the picture.

  1. ConfirmMeasure and reassess

    Repeat blood pressure correctly and review gestation, history and medication.

  2. EvaluateLook for organ or placental dysfunction

    Symptoms, urine protein, blood count, liver, kidney and fetal assessment.

  3. ClassifyStable or severe?

    Identify severe features, progression and whether outpatient care is safe.

  4. BalanceTreat, monitor or deliver

    Balance maternal deterioration against prematurity with a documented escalation plan.

Severe headache, visual change, upper abdominal pain, breathlessness, seizure or reduced fetal movements needs urgent assessment.

Sources and further reading

  1. ACOG — Preeclampsia and High Blood Pressure During Pregnancy
  2. NICE — Hypertension in pregnancy