Preeclampsia is a pregnancy complication where dangerously high blood pressure develops, typically after 20 weeks of pregnancy, and it can damage organs throughout the body. It affects roughly 4.4% of pregnancies worldwide. Left untreated, it can progress to seizures, organ failure, and life-threatening emergencies for both mother and baby.
What Causes Preeclampsia
The problem starts with the placenta. Early in a normal pregnancy, the blood vessels that supply the placenta remodel themselves to allow a large, steady flow of blood. In preeclampsia, that remodeling is incomplete. The arteries stay narrow, and the placenta doesn’t get enough blood.
A poorly supplied placenta releases signals into the mother’s bloodstream that disrupt the lining of blood vessels throughout her body. Specifically, the placenta produces an excess of proteins that block normal blood vessel growth and maintenance. This triggers widespread inflammation and damage to the inner walls of blood vessels in the kidneys, liver, brain, and other organs. That vascular damage is what drives nearly every symptom and complication of preeclampsia.
Warning Signs and Symptoms
Preeclampsia is diagnosed when blood pressure reaches 140/90 or higher on two readings at least four hours apart. Severe-range preeclampsia starts at 160/110. Protein leaking into the urine is a hallmark sign, reflecting kidney damage, but preeclampsia can also be diagnosed based on other organ involvement even without protein in the urine.
Many women with early preeclampsia feel fine, which is part of what makes it dangerous. As the condition progresses, symptoms can include:
- Severe headaches that don’t respond to usual remedies
- Vision changes, including blurriness, light sensitivity, or temporary vision loss
- Pain in the upper right abdomen, just below the ribs
- Nausea or vomiting that appears later in pregnancy
- Shortness of breath from fluid building up in the lungs
- Sudden swelling of the face and hands
- Sudden weight gain over a few days
These symptoms can escalate quickly. A headache and visual disturbances in particular can signal that the brain is being affected, which raises the risk of seizures.
How It Affects the Body
Preeclampsia is a systemic condition, meaning it doesn’t stay confined to blood pressure. The damaged blood vessel lining causes problems in multiple organs at once.
Kidneys: The filtering units of the kidneys swell and leak protein into the urine. In severe cases, kidney function can decline significantly, reducing the body’s ability to filter waste and regulate fluid balance.
Liver: Up to 10% of women with severe preeclampsia develop abnormal liver function, with enzyme levels rising to two or three times normal. The liver can develop areas of tissue death and clotting within its small blood vessels. Right-sided abdominal pain is the most recognizable sign of liver involvement.
Brain: Swelling and blood vessel spasms in the brain can cause severe headaches, visual disturbances, confusion, and in the worst cases, seizures. When preeclampsia triggers seizures, it becomes eclampsia, a medical emergency.
Blood: Platelet counts can drop, reducing the blood’s ability to clot. Red blood cells can be physically sheared apart as they pass through damaged blood vessels, leading to a type of anemia.
HELLP Syndrome
HELLP is a severe complication that can develop alongside preeclampsia. The name stands for hemolysis (red blood cell destruction), elevated liver enzymes, and low platelets. It’s diagnosed when all three are present: red blood cells are breaking apart in the bloodstream, liver enzymes are at least double the normal level, and platelet counts fall below 100,000 per microliter.
HELLP can develop rapidly and sometimes appears in women who didn’t seem to have severe preeclampsia. It carries a higher risk of liver rupture, stroke, and kidney failure. The symptoms often overlap with preeclampsia itself, particularly upper abdominal pain, nausea, and headache, which can make it harder to recognize as a distinct escalation.
How Preeclampsia Is Managed
The only cure for preeclampsia is delivering the baby and the placenta. Every management decision revolves around balancing the risks of continuing the pregnancy against the risks of early delivery.
If the condition develops before the baby is far enough along to safely deliver, the goal is to manage blood pressure, prevent seizures, and buy time for the baby’s lungs and organs to mature. Blood pressure medications bring readings down to a safer range. Corticosteroids may be given to accelerate the baby’s lung development if early delivery looks likely.
Magnesium sulfate is given through an IV to prevent seizures. It works in several ways: it relaxes blood vessel walls to reduce spasms, it helps protect the barrier between the bloodstream and the brain to limit swelling, and it raises the threshold for seizure activity in the brain. It’s one of the most effective interventions in obstetric medicine and is standard for any woman with severe preeclampsia.
When preeclampsia is severe or when it develops at or near full term, delivery is the recommended course. If the condition deteriorates rapidly, that delivery may need to happen within hours regardless of gestational age.
The Risk Doesn’t End at Delivery
Many people assume the danger passes once the baby is born, but preeclampsia can develop for the first time after delivery. Postpartum preeclampsia is diagnosed when new high blood pressure appears between 48 hours and 6 weeks after birth, though most cases show up within the first 7 to 10 days. Cases have been reported as late as 3 months postpartum.
Headache is the most common symptom, reported by 60 to 70% of women with delayed-onset postpartum preeclampsia. Other signs include shortness of breath, chest pain, and new swelling. In 10 to 15% of postpartum cases, the first sign is a seizure. Postpartum preeclampsia may actually carry a higher risk of serious complications than the version that develops during pregnancy, partly because women and their care teams are less vigilant after delivery. Women readmitted to the hospital with new postpartum hypertension face an elevated risk of both eclampsia and stroke.
Long-Term Cardiovascular Effects
Preeclampsia leaves a lasting imprint on cardiovascular health. Women who have had preeclampsia face a two- to four-fold increased risk of heart disease, stroke, and chronic high blood pressure later in life compared to women who had uncomplicated pregnancies.
Research published in the American Heart Association’s journal Hypertension found that the risk increases with longer duration of the disease. For every additional day a woman has preeclampsia before delivery, her risk of developing cardiovascular disease before age 55 rises by 1 to 2%. This association held even after accounting for other risk factors like BMI, age, smoking, and diabetes.
This doesn’t mean preeclampsia directly causes heart disease decades later. It likely reveals an underlying vulnerability in the cardiovascular system that pregnancy stress exposes. Either way, a history of preeclampsia is a meaningful piece of health information worth sharing with any doctor managing your long-term care, since earlier screening and proactive management of blood pressure and cholesterol can make a real difference.