Preeclampsia is one of those words you may hear at an antenatal visit and then forget—until a blood pressure reading climbs, your hands swell, or a headache appears that feels unlike your usual one. Questions can come fast: Is it serious? Is the baby okay? Should I go to the hospital now?
The reassuring part is that early detection truly changes outcomes. Regular BP checks, urine testing, blood work when needed, and monitoring the baby help clinicians diagnose preeclampsia, decide if there are severe features, and make a plan focused on keeping both parent and baby safe.
Preeclampsia: what it is and why it matters
What preeclampsia is (high blood pressure and organ strain)
Preeclampsia is a pregnancy complication defined by new-onset high blood pressure (hypertension) after mid-pregnancy, together with signs that the body is under strain—most commonly the kidneys, liver, blood system (platelets and clotting), brain, or lungs. It is not only about BP numbers. It is a placenta-driven, whole-body condition, and it can change quickly.
Clinicians diagnose preeclampsia when blood pressure is elevated and there is either:
- proteinuria (protein leaking into urine), or
- evidence of organ involvement (for example low platelets, rising creatinine, elevated liver enzymes, pulmonary edema, or neurologic/visual symptoms).
The goal of close monitoring is twofold: protect the parent (kidneys, liver, brain, lungs, clotting) and protect the baby (placental blood flow, oxygenation, growth).
When preeclampsia can happen (and postpartum risk)
Preeclampsia typically appears after 20 weeks, often in the third trimester. It can also begin during labour, or after delivery.
Timing terms you may hear:
- Early-onset (before 34 weeks)
- Late-onset (34 weeks or later)
Postpartum preeclampsia can develop in the days after birth and up to about 6 weeks postpartum. New symptoms after delivery—especially severe headache or vision changes—should be checked promptly.
Preeclampsia vs gestational hypertension vs chronic hypertension
- Gestational hypertension: new BP elevation after 20 weeks, without proteinuria and without organ dysfunction at diagnosis.
- Preeclampsia: new BP elevation after 20 weeks plus protein in urine and/or organ dysfunction.
- Chronic hypertension: high BP present before pregnancy, diagnosed before 20 weeks, or persisting after delivery.
This difference matters because preeclampsia carries higher risks (seizures, stroke, placental problems, growth restriction) and changes monitoring and delivery planning.
Superimposed preeclampsia on chronic hypertension
If someone already has chronic hypertension, preeclampsia can “layer on top” (superimposed preeclampsia). It is suspected when BP becomes harder to control or when new findings appear:
- new/worsening urine protein
- platelets dropping
- creatinine rising
- liver enzymes rising
- new headache/vision symptoms
- pulmonary edema
Diagnosis can be trickier because baseline BP (and sometimes baseline urine protein) may already be abnormal.
How preeclampsia relates to eclampsia and HELLP syndrome
- Eclampsia is when seizures occur in the setting of preeclampsia, without another cause found. It is an obstetric emergency.
- HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets) is a severe variant involving the blood and liver. It can present with upper abdominal pain, nausea/vomiting, and abnormal labs, and often leads to expedited delivery.
Preeclampsia with severe features
What “severe features” means
“Severe features” means the condition is affecting the body more intensely and the risk of complications is higher. Even one severe feature can change care.
Severe features include:
- Severe-range BP: systolic ≥160 mmHg or diastolic ≥110 mmHg (confirmed)
- Platelets <100,000/µL
- Creatinine ≥1.1 mg/dL or doubling from baseline
- Liver involvement: markedly elevated AST/ALT or new right upper abdominal/epigastric pain
- Pulmonary edema
- New neurologic/visual symptoms (severe headache, blurred vision, seeing spots)
This often means hospital care, tighter monitoring, medication to prevent seizures, and earlier delivery planning.
Why preeclampsia happens in the body (simple medical picture)
Preeclampsia begins with the placenta. Early in pregnancy, placental blood vessels should remodel so blood can flow easily. In preeclampsia, remodeling can be incomplete: the placenta receives less steady blood flow and becomes stressed.
A stressed placenta releases signals into the parent’s bloodstream that affect the endothelium (blood vessel lining). Blood vessels constrict more than expected (BP rises), become leakier (fluid shifts and swelling), and clotting regulation can change. Because blood vessels are everywhere, multiple organs can show strain (kidneys, liver, brain, lungs, blood).
Preeclampsia symptoms and warning signs
Why you can feel fine even with high blood pressure
High BP is often silent. Many parents with preeclampsia feel normal at first, and it is picked up only because routine BP or urine testing is abnormal. Symptoms can also appear suddenly.
Blood pressure, swelling, and sudden weight gain
Common findings may include:
- elevated BP (often no symptoms)
- swelling in legs, hands, face
- rapid weight gain over a short period (fluid-related)
Swelling can happen in normal pregnancy. More concerning is sudden onset, marked swelling (especially face/hands), rapid worsening, or swelling together with headache, vision changes, pain, or rising BP.
Headache and vision changes
Concerning signs include:
- severe or persistent headache (especially not improving)
- blurred vision, light sensitivity, spots/flashes
These can reflect brain involvement and need prompt assessment.
Upper abdominal pain (right upper quadrant/epigastric pain)
Pain under the right ribs or upper middle abdomen can be a sign of liver irritation or HELLP. If it is new, strong, or persistent—especially with nausea or headache—get checked.
Nausea/vomiting, shortness of breath, and decreased urination
Warning patterns include:
- nausea/vomiting that starts or suddenly worsens after 20 weeks, especially with headache/vision symptoms/upper abdominal pain
- new or worsening shortness of breath, difficulty lying flat, chest tightness
- markedly decreased urine output
Decreased fetal movements
If you notice clearly reduced fetal movements, contact your maternity team promptly. If reduced movements happen together with severe maternal symptoms, urgent evaluation is safest.
When to seek urgent care for preeclampsia
Seek same-day evaluation (or emergency care) for:
- severe/persistent headache
- new vision changes
- severe upper abdominal pain
- seizure, fainting, confusion, or sudden neurologic symptoms
- breathlessness/chest pain
- home BP around or above 160/110 mmHg
If you are unsure whether to call, it is reasonable to get checked. A quick BP reading, urine test, and blood work can clarify the situation.
When a home blood pressure reading is concerning
General thresholds commonly used:
- repeated readings ≥140/90: contact your doctor/maternity unit for advice.
- any reading ≥160/110: urgent evaluation is needed.
Symptoms matter. If you have headache, vision changes, upper abdominal pain, or breathlessness, seek care even if the number is not extremely high.
How preeclampsia is diagnosed
Blood pressure thresholds and accurate measurement
Diagnosis starts with BP:
- Hypertension: ≥140/90 mmHg on two readings at least 4 hours apart after 20 weeks
- Severe-range: ≥160/110 mmHg (needs urgent treatment)
Accurate technique matters: proper cuff size, seated position, arm at heart level, and resting a few minutes before readings.
Proteinuria testing
Protein in urine can be assessed by:
- spot urine protein/creatinine ratio (significant if ≥0.3), or
- 24-hour urine collection (significant if ≥300 mg/24 hours).
Dipstick is quick screening but can be imprecise.
Diagnosis without proteinuria
Preeclampsia can still be diagnosed without protein in urine if there is hypertension plus organ dysfunction such as:
- platelets <100,000/µL
- creatinine ≥1.1 mg/dL or doubling from baseline
- AST/ALT ≥2× normal
- pulmonary edema
- new cerebral or visual symptoms
Blood tests and trends
Blood tests help assess severity:
- platelets
- creatinine/urea
- AST/ALT
- sometimes LDH and clotting tests, based on the clinical picture
Trends over time often matter more than one value.
Monitoring the baby
Because preeclampsia can reduce placental function, monitoring may include:
- growth ultrasound and amniotic fluid checks
- Doppler studies (often umbilical artery flow)
- NST and/or BPP depending on gestational age and risk
Who is at risk for preeclampsia
Risk is higher with:
- first pregnancy
- previous preeclampsia
- family history
- chronic hypertension
- diabetes
- kidney disease
- overweight/obesity
- autoimmune disease (lupus, antiphospholipid syndrome)
- twins/multiples
- maternal age over 35
- assisted reproduction (including IVF)
Preventing preeclampsia and reducing risk
Low-dose aspirin (only with medical advice)
For higher-risk pregnancies, low-dose aspirin can reduce the risk of preeclampsia. It is usually started between 12 and 28 weeks (often ideally before 16 weeks) and continued as prescribed. Do not start it on your own.
Calcium supplementation (when intake is low)
Calcium supplementation may reduce risk where dietary calcium intake is low. Your clinician can advise dose and timing.
Managing chronic conditions
Good control of chronic hypertension, diabetes, and kidney disease before and during pregnancy can reduce complications and helps your team plan monitoring.
Treating and managing preeclampsia
Goals of treatment
Treatment focuses on:
- preventing complications (especially seizures and stroke)
- monitoring organ function and the baby
- choosing the safest time for delivery
Delivery (removing the placenta) is the definitive treatment, but timing is balanced against prematurity risk.
Without severe features vs with severe features
- Without severe features: sometimes managed with frequent outpatient checks if parent and baby are stable and access to care is reliable.
- With severe features: usually needs hospital admission for close monitoring, BP control, and seizure prevention.
Common medicines used
- Antihypertensives (labetalol, nifedipine, hydralazine) may be used, especially for severe-range BP, to reduce stroke risk.
- Magnesium sulfate is used to prevent seizures in severe disease and to treat seizures if they occur.
- Corticosteroids may be given before 34 weeks if preterm delivery is likely, to support fetal lung maturity.
- Fluids are managed carefully to avoid worsening pulmonary edema.
Preeclampsia and delivery planning (what often guides timing)
Common patterns:
- Without severe features: delivery is often planned around 37 weeks
- With severe features: delivery is generally recommended at or after 34 weeks, or earlier if parent or baby becomes unstable
- Before 34 weeks: in selected stable situations, close monitoring may aim to gain time for fetal maturity, but delivery is not delayed if risk rises
Mode of delivery is individualised: induction when feasible, caesarean when rapid delivery is needed or there are obstetric reasons.
Postpartum preeclampsia
Postpartum preeclampsia can begin after birth or persist after delivery. Warning signs include:
- severe headache
- vision changes
- upper abdominal pain
- breathlessness or chest symptoms
- sudden, significant swelling
- high home BP readings
Because sleep deprivation can blur the picture, new neurologic or visual symptoms should not be ignored.
Follow-up after discharge usually includes BP checks soon after discharge and again in the weeks after birth, plus clear thresholds for urgent review.
Long-term health after preeclampsia
A history of preeclampsia increases the likelihood of chronic hypertension later and is linked with higher long-term cardiovascular risk (heart disease, stroke). Some parents also have higher long-term kidney risk, especially after severe or early-onset disease.
Preeclampsia can act like an early “stress test” for blood vessels. Ongoing follow-up with a primary care clinician is meaningful.
Key takeaways
- Preeclampsia combines high BP after 20 weeks with signs of maternal organ stress, protein in urine is common but not required.
- It can be silent at first, so routine BP and urine checks matter.
- Seek urgent care for severe headache, vision changes, upper abdominal pain, breathlessness/chest symptoms, severe-range BP, neurologic symptoms, decreased urination, or decreased fetal movements.
- Evaluation includes BP, urine testing, blood tests (platelets, creatinine, AST/ALT), and fetal monitoring (growth ultrasound, Dopplers, NST/BPP).
- Treatment focuses on stabilising the parent, preventing seizures with magnesium sulfate when indicated, controlling severe BP, and planning delivery at the safest time.
- Postpartum symptoms matter: preeclampsia can begin or worsen after birth up to about 6 weeks.
- Long-term follow-up for BP, heart health, and kidney health is worthwhile, and you can download the Heloa app for personalised guidance and free child health questionnaires.
Questions Parents Ask
Can preeclampsia happen without protein in the urine?
Yes. It can feel confusing, so please don’t doubt yourself if symptoms are strong but urine tests look “normal.” Preeclampsia may be diagnosed with high blood pressure plus signs that an organ is under strain (for example: low platelets, rising creatinine, elevated liver enzymes, fluid in the lungs, or persistent neurologic/visual symptoms). If you have concerning symptoms, a full assessment (BP + blood tests + clinical exam) can be more informative than urine alone.
How likely is preeclampsia to come back in a future pregnancy?
Many parents go on to have a healthy next pregnancy. The chance of recurrence depends on your history (early-onset or severe disease, HELLP, underlying hypertension/kidney disease, twins, etc.). In a future pregnancy, your team may suggest earlier and closer monitoring, and sometimes low-dose aspirin if your risk profile supports it. If you’re planning another baby, a preconception visit can be reassuring and practical.
After preeclampsia, how long does it take for blood pressure to go back to normal?
For many, blood pressure improves over days to weeks after birth, but it can stay high for a while—especially if you needed medication. Postpartum spikes can also happen, which is why follow-up checks are important. If high readings persist beyond about 12 weeks postpartum, your clinician may discuss chronic hypertension and longer-term care, with supportive options available.
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