What Is Preeclampsia? Ob-Gyns Explain the Serious Pregnancy Complication

Pregnancy can come with a whole host of side effects — from pregnancy nose to gestational diabetes. It can also be accompanied by certain complications, with some more serious than others. One potentially fatal complication is preeclampsia.

Preeclampsia is a condition that usually develops in the third trimester of pregnancy and is characterized by high blood pressure, says Stephanie Hack, MD, an ob-gyn and the founder of Lady Parts Doctor. "It can affect multiple organs and is a precursor to eclampsia, a condition with high blood pressure and seizures."

The condition has been thrust into the news in recent years as celebrities like Kim Kardashian have opened up about the experience. And in 2023, Olympic champion Tori Bowie passed away from complications related to childbirth and preeclampsia.

Black pregnant people bear a disproportionate burden of pregnancy risk, including preeclampsia, in the United States, says Alison Cowan, MD, an ob-gyn and the head of medical affairs at Mirvie, a company developing predictive testing for life-threatening pregnancy complications. "Black individuals have approximately a threefold increased risk of dying in pregnancy overall and are five times more likely to die from preeclampsia and eclampsia than white women," she explains. Additionally, Black women are five times more likely to die from postpartum cardiomyopathy (a related condition that is much more common in individuals with preeclampsia) than white women, she adds.

Overall, preeclampsia affects roughly one in 25 pregnancies, per Johns Hopkins Medicine, so it's incredibly important to know your risk. Here's everything you need to know about preeclampsia, including the signs and symptoms, how quickly it can develop, and how it's treated.

Experts Featured in This Article:

Alison Cowan, MD, an ob-gyn and the head of medical affairs at Mirvie.

Stephanie Hack, MD, is an ob-gyn and the founder of Lady Parts Doctor.

What Is Preeclampsia?

Preeclampsia is a pregnancy complication that has symptoms that can range from mild to severe. "With preeclampsia, you might have high blood pressure, high levels of protein in urine that indicate kidney damage (proteinuria), or other signs of organ damage," Mayo Clinic reports.

Symptoms of preeclampsia "can also be completely silent, which is why it is so important to know your risk of preeclampsia in pregnancy and to have regular care and blood pressure checks," Dr. Cowan says. The condition typically occurs after 20 weeks in pregnancy and becomes more common as pregnancy progresses, she adds.

What Causes Preeclampsia?

Unfortunately, the causes of preeclampsia are not fully understood, which is one of the reasons it's so challenging to predict and prevent, Dr. Cowan says. "It likely has to do with abnormalities in the placenta's implantation that ultimately result in the development of high blood pressure over time," she explains.

To break this down further, the placenta is the organ that nourishes the fetus throughout pregnancy, and in the early stages, new blood vessels develop and evolve to supply oxygen and nutrients to the placenta, per Mayo Clinic. In women with preeclampsia, research suggests these blood vessels do not develop or work properly, which causes irregular regulation of blood pressure in the pregnant person.

Symptoms of Preeclampsia

The first warning sign of preeclampsia is high blood pressure, with a reading of 140/90 or higher, says Dr. Cowan. Additional symptoms can include the following:

That said, many cases of preeclampsia are silent and asymptomatic, Dr. Cowan says. "This is why it is so important to have regular blood pressure checks, which we recommend more frequently for individuals at higher risk, and at the end of pregnancy for all, when preeclampsia is more common."

How Quickly Can Preeclampsia Develop?

Preeclampsia can occur without warning and can evolve quite rapidly, Dr. Cowan says. "Some risk factors, such as high blood pressure outside of pregnancy or a history of preeclampsia, can help us to identify who is at increased risk."

However, many otherwise healthy women without apparent risk factors develop preeclampsia within a matter of hours and it's very difficult to predict, she adds.

How Common Is Preeclampsia?

Preeclampsia impacts an estimated one in 25 pregnancies, so it's more important than ever for women and pregnant individuals to know their risk, Dr. Cowan says. "We've seen that diseases related to the cardiovascular system are the leading cause of pregnancy-related mortality in the United States, together making up 29 percent of pregnancy-related deaths."

A 2022 study published in the Journal of the American Heart Association found that high blood pressure in pregnancy is on the rise, having doubled between 2007 and 2019. "With the trends we're currently seeing, it's paramount to increase awareness about preeclampsia so that pregnant individuals can know their risk and do everything they can to prevent preeclampsia or, at minimum, to recognize it immediately if it does develop," Dr. Cowan stresses.

How to Prevent Preeclampsia

The first step to preeclampsia prevention is knowing your risk, Dr. Cowan says. Women with certain major risk factors such as chronic high blood pressure, type 1 or type 2 diabetes, or a history of prior preeclampsia are known to be at high risk, she explains. The challenge today is that many individuals with no apparent risk factors go on to develop preeclampsia, so it makes prevention more difficult, she adds.

Right now, there is currently no reliable way to predict preeclampsia before symptoms occur, but there are several strategies to prevent preeclampsia from occurring or to at least recognize when it happens, Dr. Cowan says.

Research out of Mayo Clinic found that the best clinical evidence for prevention is using low-dose aspirin. The exact mechanism for how baby aspirin staves off preeclampsia isn't known, but studies suggest that aspirin helps at-risk patients to have more normal placental development. That being said, it's important to talk with your doctor before regularly starting any medications, vitamins, or supplements.

Additionally, the American Pregnancy Association recommends using little or no added salt in your meals, drinking six to eight glasses of water a day, exercising regularly, avoiding alcohol and caffeine, and getting adequate rest.

Another helpful resource is this Mirvie checklist for patients and guidelines for providers, which is a great tool to assess your risk of preeclampsia, Dr. Cowan says. "This care plan brings together all of the evidence-based interventions that women can act on when they know their risk, which includes strategies as simple as regular home blood pressure monitoring, taking a baby aspirin every day, and getting targeted lab work done at your doctor's office."

Preeclampsia Treatment

It's often said the "cure" for preeclampsia is delivering the baby, which is largely true, Dr. Cowan says. "When preeclampsia develops earlier in pregnancy, we try to do everything we can to manage it, sometimes with medications and close monitoring to prolong the pregnancy a bit longer," she explains. However, any time preeclampsia develops at 37 weeks or beyond, the recommendation is to proceed with delivery (usually an induction of labor or C-section), she adds.

If extreme features of preeclampsia such as lab abnormalities or severely elevated blood pressure develop, then preeclampsia is often treated with magnesium sulfate, Dr. Cowan explains. "This is given through the IV and has been shown to significantly decrease the chances of eclampsia, which are seizures in the setting of preeclampsia."

If preeclampsia with severe features goes unrecognized, eclampsia can develop in approximately two to three percent of untreated women and can be life-threatening for mom and baby, Dr. Cowan adds.

Andi Breitowich is a Chicago-based freelance writer and graduate from Emory University and Northwestern University's Medill School of Journalism. Her work has appeared in PS, Women's Health, Cosmopolitan, and elsewhere.