If you are pregnant (or recently delivered) and have any of these, call your OB or 911 right now — do not wait for your next appointment: a severe headache that won’t go away or keeps getting worse, vision changes (blurring, flashing lights, spots, or loss of vision), pain in the upper-right abdomen or just below the ribs, sudden swelling of the face and hands or sudden rapid weight gain, trouble breathing, feeling faint, or any seizure. These can signal severe preeclampsia or eclampsia, which is life-threatening for both you and your baby. This box is general education, not a substitute for care from your own OB.
Roughly 3 to 8 percent of US pregnancies are complicated by preeclampsia, making it one of the leading causes of maternal and infant illness worldwide, according to CDC data on hypertensive disorders of pregnancy. Despite decades of research, the only definitive treatment is delivery of the baby and placenta. Recognizing the warning signs early, understanding your personal risk, and getting appropriate prenatal monitoring are what most affect outcomes.
This guide explains what preeclampsia actually is, who develops it, the symptoms that warrant urgent evaluation, how it is diagnosed and managed, and what the long-term cardiovascular implications look like for women who have had it. It is general education and is not a substitute for care from your own obstetric clinician. For comprehensive pregnancy-care context, see our prenatal care guide, the closely related gestational hypertension guide, and the broader medical conditions library.
What Preeclampsia Is
Preeclampsia is a hypertensive disorder of pregnancy that develops after 20 weeks of gestation. Diagnosis requires new-onset high blood pressure (140/90 mm Hg or higher on two occasions at least four hours apart) plus either proteinuria (protein in the urine) or evidence of organ dysfunction (low platelets, elevated liver enzymes, kidney impairment, pulmonary edema, or new neurologic symptoms), per the ACOG Practice Bulletin 222.
The underlying problem appears to be abnormal development of the placenta early in pregnancy, leading to widespread blood-vessel dysfunction, inflammation, and reduced organ perfusion in the second half of pregnancy. Preeclampsia exists on a spectrum: gestational hypertension (high blood pressure without organ involvement) can progress to preeclampsia, which can progress to severe preeclampsia with organ damage, to eclampsia (preeclampsia plus seizures), and to HELLP syndrome (Hemolysis, Elevated Liver enzymes, Low Platelets). Because it can move along this spectrum quickly, monitoring is central to safe care.
Who Is at Risk
Multiple factors raise preeclampsia risk. The most established include first pregnancy, prior preeclampsia (recurrence around 15 to 20 percent), chronic hypertension, pregestational diabetes, autoimmune conditions such as lupus or antiphospholipid syndrome, kidney disease, multiple gestation (twins or more), advanced maternal age (over 35), obesity (BMI over 30), Black race (likely reflecting structural inequities in healthcare access and quality more than biology), and pregnancies conceived through IVF, particularly using donor eggs.
The USPSTF and ACOG recommend low-dose aspirin, started in the early second trimester (generally between 12 and 28 weeks and ideally before 16 weeks), for people with one or more high-risk factors or two or more moderate-risk factors. This intervention reduces preeclampsia risk by roughly 15 to 25 percent in higher-risk groups. Whether aspirin is right for you, and exactly when to start it, is a decision for your OB — this guide deliberately does not provide a dose to copy, because aspirin is not appropriate for everyone and self-starting medication in pregnancy can be harmful.
Warning Signs and Symptoms
Many cases of preeclampsia are detected through routine blood pressure and urine checks at prenatal visits before symptoms appear — which is exactly why keeping every prenatal appointment matters so much. When symptoms do develop, the most concerning include a severe headache that does not respond to acetaminophen, vision changes (blurriness, flashing lights, spots, or temporary loss of vision), sudden swelling of the face and hands (some swelling of the feet is normal in pregnancy), severe pain in the upper-right abdomen or just below the breastbone, sudden weight gain (more than two to five pounds in a week), and decreased urine output.
Some women describe a general sense of being unwell, new nausea or vomiting in the second half of pregnancy (different from typical first-trimester morning sickness), or shortness of breath. Decreased fetal movement can also indicate that placental function is compromised and should always be reported promptly.
When to seek emergency care: Call 911 or go to the nearest labor-and-delivery triage if you experience a severe or worsening headache, vision changes, severe pain in the upper-right abdomen, sudden severe swelling or rapid weight gain, shortness of breath, or a seizure. These can indicate severe preeclampsia or eclampsia, which are life-threatening for both mother and baby. Trust your instincts — it is always appropriate to be checked.
How Preeclampsia Is Diagnosed
Diagnosis combines blood pressure measurements, urine testing, blood work, and clinical assessment. Two blood pressure readings of 140/90 mm Hg or higher at least four hours apart establish hypertension. The severe range is 160/110 or higher and requires prompt treatment regardless of other findings.
Proteinuria is assessed by a 24-hour urine collection (300 mg or more), a spot protein-to-creatinine ratio (0.3 or higher), or a dipstick reading (2+ or higher when other methods are unavailable). Lab work typically includes a complete blood count (looking for low platelets), liver function tests, creatinine, uric acid, and lactate dehydrogenase. Fetal assessment with ultrasound (growth, amniotic fluid, umbilical Doppler studies) and nonstress testing checks for placental insufficiency.
Newer biomarker tests measuring the ratio of soluble fms-like tyrosine kinase-1 (sFlt-1) to placental growth factor (PlGF) can help identify women at imminent risk for progressing to severe preeclampsia; a related test has been FDA-cleared for hospitalized patients and is used at some medical centers to help triage ambiguous cases. These tests supplement, but do not replace, blood pressure, urine, and clinical evaluation.
Treatment and Management
The only definitive treatment for preeclampsia is delivery of the baby and placenta. Timing depends on the severity, gestational age, and how mother and baby are doing, and it is always individualized by the care team. For preeclampsia without severe features at term (37 weeks or later), delivery is usually recommended. For preeclampsia with severe features, delivery is generally recommended at 34 weeks — or sooner if maternal or fetal condition demands it.
Between diagnosis and delivery, blood pressure is managed with medicines chosen for use in pregnancy; labetalol, nifedipine, and methyldopa are commonly used, while ACE inhibitors and ARBs are avoided in pregnancy. Magnesium sulfate is given intravenously to prevent and treat seizures in severe preeclampsia and during labor. Corticosteroids may be given to accelerate fetal lung maturity if delivery before 34 weeks is anticipated. All of these are prescriber-directed; this guide intentionally provides no doses to copy.
For preterm preeclampsia without severe features, expectant management with close monitoring may continue toward 37 weeks if mother and baby remain stable. This requires either inpatient monitoring or very frequent outpatient evaluation, including blood pressure checks, regular labs, and fetal monitoring — a plan your OB will tailor to your situation.
Effects on Mother and Baby
Preeclampsia raises immediate maternal risks of stroke, seizure, kidney failure, liver damage, pulmonary edema, placental abruption, and postpartum hemorrhage. Most mothers recover fully after delivery, but blood pressure can take days to weeks to normalize, and a small percentage develop postpartum preeclampsia, which can occur up to six weeks after delivery.
For the baby, the main risks are growth restriction (the placenta does not adequately deliver nutrients), preterm birth from medically indicated early delivery, and, in the most severe cases, stillbirth. Babies born preterm because of preeclampsia generally do well but face the standard prematurity-related complications proportional to gestational age at birth.
Postpartum Preeclampsia
Preeclampsia does not always end with delivery, and it can even appear for the first time after the baby is born — usually within the first 48 hours, but potentially up to six weeks postpartum. This is easy to miss because attention shifts entirely to the newborn. New or persistent headaches, vision changes, swelling, upper-abdominal pain, or trouble breathing in the weeks after delivery should prompt an immediate blood pressure check and evaluation. Anyone recovering from a birth — and their partners and support people — should know these warning signs and act on them without hesitation.
Long-Term Implications
Women who have had preeclampsia carry a meaningfully higher lifetime risk of cardiovascular disease, including chronic hypertension, heart attack, stroke, kidney disease, and type 2 diabetes. The American Heart Association formally recognizes preeclampsia as a sex-specific risk factor for cardiovascular disease and recommends lifelong cardiovascular risk monitoring.
Practical implications include regular blood pressure monitoring, periodic lipid and glucose checks, attention to weight and physical activity, and informed communication with your primary care provider about your pregnancy history. Women planning future pregnancies after preeclampsia should ideally be evaluated by a maternal-fetal medicine specialist, discuss low-dose aspirin for the next pregnancy with their clinician, and plan for closer monitoring.
Frequently Asked Questions
Can preeclampsia be prevented?
Not entirely. Low-dose aspirin started in the early second trimester reduces risk in people with high-risk factors, and calcium supplementation may help those with low dietary intake. Maintaining a healthy weight before pregnancy, controlling chronic hypertension, and managing diabetes also lower risk. No intervention prevents all cases — which is why monitoring and recognizing warning signs remain essential. Talk to your OB about what is right for you rather than self-starting any medication.
Will I get preeclampsia in my next pregnancy?
Recurrence risk is roughly 15 to 20 percent overall and higher (around 25 to 50 percent) if the original case was severe, occurred before 34 weeks, or involved HELLP syndrome. Pre-pregnancy consultation, low-dose aspirin when advised, and close prenatal monitoring reduce recurrence risk.
How quickly does blood pressure return to normal after delivery?
Most women see blood pressure improve within a few days to two weeks, though it can briefly worsen first. Some require blood pressure medication for several weeks postpartum. About 10 to 15 percent of women develop chronic hypertension after preeclampsia, which often becomes apparent within five to ten years — another reason for ongoing primary care follow-up.
Can preeclampsia happen after delivery?
Yes. Postpartum preeclampsia can develop up to six weeks after delivery, most often in the first 48 hours. Persistent or new-onset headaches, vision changes, swelling, or upper-abdominal pain after delivery should prompt immediate evaluation and a blood pressure check — call your OB or 911 for severe symptoms.
How is preeclampsia different from gestational hypertension?
Gestational hypertension is high blood pressure after 20 weeks without protein in the urine or organ involvement. Preeclampsia adds proteinuria or signs of organ dysfunction. Gestational hypertension is the most common pathway to preeclampsia, so it is monitored closely. See our gestational hypertension guide for more.
The Bottom Line
Preeclampsia is a serious but treatable pregnancy complication when caught early. Knowing your risk factors, attending prenatal visits consistently, recognizing the warning signs that need urgent evaluation, and following up on blood pressure after delivery are the most important steps. Treatment — including whether to take aspirin, which blood pressure medicine to use, and when to deliver — is always directed by your OB. For women who have had preeclampsia, lifelong cardiovascular-risk awareness and good primary care matter as much as any single pregnancy decision.