Preeclampsia and Pregnancy
Be aware of the symptoms of high blood pressure to start treatment right away
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Medically reviewed by Peter Weiss, MD
Preeclampsia is a rare but serious high blood pressure condition that can occur during pregnancy. This condition occurs in about 5% of pregnancies in the United States.
Preeclampsia is highly treatable when healthcare providers detect it and intervene early. Most people receive early intervention and have healthy pregnancies and babies. However, left untreated, preeclampsia can lead to serious problems, including preterm birth and, in rare cases, death.
This article reviews signs of preeclampsia, risk factors, effects on the fetus and parent, and treatment.
Am I Showing Signs of Preeclampsia?
Healthcare providers detect preeclampsia through warning signs from blood pressure readings and urine tests during prenatal visits. Hypertension (high blood pressure) is blood pressure that's consistently higher than 140/90 millimeters of mercury (mm Hg). It is the most common early sign of preeclampsia.
Your healthcare provider will periodically test your urine for protein during prenatal visits. Levels may progressively increase over weeks or months if preeclampsia worsens.
Risk factors for preeclampsia include:
Personal or family history of preeclampsia
Pregnant with multiples (twins, triplets, etc.)
A history of high blood pressure, pregestational diabetes, kidney disease, thyroid problems, sleep disorders, and some autoimmune disorders
Never having a baby (or it's been 10 years since you had one)
Obesity
Prior pregnancy complications like low birth weight, abruption, or stillbirth
Fertility treatment
Advanced maternal age (being older than 35)
Fetal diseases (hydrops fetalis, viral infections, Trisomy 13)
Maternal infection or inflammation (periodontal disease, COVID-19, urinary tract infections)
When Does Preeclampsia Start?
Preeclampsia can occur anytime after 20 weeks of pregnancy. But most cases occur between weeks 34 and 37, as noted below.
Early onset (less than 34 weeks): Rare, occurring in around 10% of cases
34 to 37 weeks: Common, occurring in approximately 85% of cases (can happen during delivery)
Postpartum preeclampsia: Rare, with about 5% of cases occurring after delivery (typically 48 hours after birth)
Related: A Blood Test Could Predict Early Preeclampsia Warning Signs, Study Says
New or Worsening Preeclampsia Symptoms That Require Treatment
While most cases of preeclampsia are mild, the condition can quickly progress to severe preeclampsia or eclampsia (seizures and coma) within a few days. About 25% of those with preeclampsia develop severe preeclampsia.
Healthcare providers suspect worsening preeclampsia based on “alarm” signs and symptoms. This includes a blood pressure above 160/110 mm Hg and one or more of the following symptoms:
Severe headache: A persistent headache that doesn’t go away
Abdominal (belly) pain: A constant achy or sharp belly pain that is typically on the right side, under your ribs
Vision changes: Blurriness, seeing spots, changes in eyesight, flashing lights, or light sensitivity
Breathing difficulties: Dyspnea (shortness of breath)
Mental status changes: Confusion or agitation
Swelling: This is different than the typical mild pregnancy swelling and involves severe and sudden swelling in the face, hands, or legs
Sudden weight gain: Rapid weight gain (more than five pounds in one week)
Seizures: Preeclampsia can progress to eclampsia, which may result in seizures
Chest pain: Chest pain is an alarming sign requiring immediate medical attention
HELLP Syndrome
Another indication that preeclampsia may be worsening is HELLP syndrome. HELLP refers to a group of symptoms that may be the first warning of preeclampsia and include:
H: Hemolysis (destruction of red blood cells)
EL: Elevated liver enzymes
LP: Low platelet counts (increases the risk of severe bleeding)
HELLP is a rare condition in 1 or 2 out of 1,000 pregnancies. However, the risk increases for those with preeclampsia. Around 10% to 20% of those with preeclampsia or eclampsia develop HELLP.
Preeclampsia: Effects on Baby
Most people with preeclampsia seek early intervention and have healthy pregnancies and babies. But left untreated, preeclampsia can cause complications for the fetus.
Preeclampsia can reduce the amount of amniotic fluid (the liquid that surrounds the fetus in the uterus), causing a restriction of blood flow, oxygen, and nutrients to the placenta. This might affect fetal growth and development, resulting in low birth weight.
Rarely, severe preeclampsia can lead to complications such as placental abruption (separation of the placenta from the uterus), premature birth, or stillbirth. The highest risk to the fetus is preeclampsia before 34 weeks (infrequent and occurs in about 10% of preeclampsia cases).
Placental Abruption
Placental abruption is when the placenta separates from the uterine wall before delivery. It is a rare, life-threatening event, occurring in about 1% of those with preeclampsia and 3% of those with severe preeclampsia.
Preeclampsia: Effects on Birthing Parent
Attending all prenatal care checkups, even if you feel well, is vital and allows your healthcare providers to monitor you for signs of preeclampsia. Early detection, monitoring, and interventions are critical to minimizing preeclampsia complications.
How Quickly Can Preeclampsia Develop?
Blood pressure may gradually rise, reading about 135/85 mm Hg for a couple of weeks before reaching hypertension between 34 and 37 weeks. However, preeclampsia can develop more quickly when it occurs before 34 weeks or postpartum (after giving birth).
Left untreated, preeclampsia can lead to severe preeclampsia or eclampsia, putting the birthing parent at risk for:
Hemorrhage (severe bleeding)
Seizures, which can lead to a coma
Organ damage or failure (kidneys, liver, brain)
Heart problems, including heart failure
Having preeclampsia during pregnancy also increases the risk of cardiovascular (heart or blood vessels) disease, hypertension, kidney disease, and strokes in the future.
How a Provider Treats Preeclampsia
While it can be dangerous, preeclampsia is highly treatable. Regular prenatal visits are critical in detecting and managing this condition. A healthcare provider will develop a treatment plan based on the severity of your preeclampsia.
High-risk for preeclampsia: Treatment involves frequently monitoring your blood pressure, checking your urine, and testing organ function through blood work. Some providers may prescribe a low-dose aspirin for you to take daily throughout pregnancy.
Mild preeclampsia: May require an antihypertensive (medication to lower blood pressure), frequent monitoring, reduced activity, and frequent follow-up visits. Providers may suggest inducing labor around 37 weeks.
Severe preeclampsia: Requires hospitalization for closer monitoring and medications. Treatment will likely include antihypertensives, corticosteroids (to help the fetus's lungs), anti-seizure medications, and intravenous (IV) fluids.
Worsening severe preeclampsia or eclampsia: Delivery is the only treatment for worsening or extremely severe cases. Depending on the situation, the provider may suggest inducing labor or having a surgical delivery called a cesarean-section (C-section).
How Long Can I Be Pregnant With Preeclampsia?
For common preeclampsia (between 34 and 37 weeks), providers typically suggest inducing labor around 37 weeks. When preeclampsia occurs before 34 weeks, they will weigh the benefits of continuing pregnancy against the risk of preterm delivery. Providers will advise immediate delivery to avoid death for the parent or baby.
Severe preeclampsia and HELLP syndrome almost always indicate early delivery, which can be life-threatening and cause liver damage.
Related: What Happens Each Week During Pregnancy?
Preeclampsia Follow-Up Care
After delivery, a healthcare provider will continue to monitor your blood pressure and organ function. They may prescribe medications for postpartum management and recommend follow-up visits to assess long-term health.
Even if you did not show signs of preeclampsia during pregnancy, your provider will monitor you after birth due to the increase in postpartum preeclampsia cases.
Summary
Preeclampsia is a severe but rare high blood pressure condition that can occur anytime after 20 weeks of pregnancy, though most cases occur around 34 to 37 weeks. It is highly treatable, but left untreated, preeclampsia can lead to severe problems, including organ damage, seizures, preterm delivery, and death.
Prenatal visits are essential because early detection and intervention are critical for minimizing risk. Treatment depends on the severity and may involve monitoring, medications, bed rest, hospitalization, inducing labor, or having a C-section delivery.
