Preeclampsia (pre-e-CLAMP-si-a) is a condition unique to human pregnancy. It is diagnosed by the elevation of the expectant mother’s blood pressure usually after the twentieth week of pregnancy combined with the appearance of excessive protein in her urine. Important symptoms that may suggest preeclampsia are headaches, abdominal pain, visual disturbances such as oversensitivity to light, blurred vision, seeing flashing spots or auras, shortness of breath or burning behind the sternum, nausea and vomiting, confusion or heightened state of anxiety. Preeclampsia and related hypertensive disorders of pregnancy impact 5-8% of all births in the United States.
Most women with preeclampsia will deliver a healthy baby and fully recover. However, some women will experience complications, several of which may be life-threatening to mother and/or baby. A woman’s condition can go from a mild form of preeclampsia to severe preeclampsia very quickly.
Preeclampsia and other hypertensive disorders of pregnancy can be devastating diseases, made worse by delays in diagnosis or management, seriously impacting or even killing both women and their babies before, during or after birth.
What is the difference between preeclampsia, toxemia, PET and PIH?
There are two forms of preeclampsia:
You may encounter other names like toxemia, PET (pre-eclampsia/toxemia) and PIH (pregnancy induced hypertension) EPH gestosis (edema, proteinuria, hypertension), but these designations are all outdated terms and no longer used by medical experts.
The Preeclampsia Foundation also focuses on two other hypertensive disorders of pregnancy, which include:
Many factors guide a health care provider’s decision about how to manage preeclampsia, including the gestational age and health of the baby, overall health and age of the mother, and a careful assessment of how the disease is progressing. This includes monitoring blood pressure and assessing the results of laboratory tests that indicate the condition of the mother’s kidneys, liver, or the ability of her blood to clot. Other tests monitor how well the unborn baby is growing and/or if he or she seems in danger. When the pregnancy is less than 37 weeks the caregiver usually tries to gain some time, but if 37 weeks or later, the provider will often opt to deliver the baby.
The healthcare provider will watch for signs of instability in the mother, including very high blood pressure that’s not responding to antihypertensive drugs, signs the kidneys and/or liver are failing, and a reduced number of red blood cells or platelets. Providers also watch closely for indications of an impending seizure or signs the brain is about stroke, and may treat the patient with magnesium sulfate (an anticonvulsant specifically used for preeclampsia). Antihypertensive drugs may be used if blood pressure rises to dangerously high levels.
If the baby is growing insufficiently, not at all, or scores poorly on a “stress test,” he or she may not survive if left in the uterus. Even if the baby is very premature, delivery may be required if the disease can not be stabilized in order to protect the mother or ensure the baby’s survival.
Eclampsia (e-CLAMP-si-a) is a very serious complication of preeclampsia characterized by one or more seizures during pregnancy or in the post-partum period. In the developed world, eclampsia is rare and usually treatable if appropriate intervention is promptly sought. Left untreated, eclamptic seizures can result in coma, brain damage, and possibly maternal or infant death.
Preeclampsia is so named because it was originally identified as a disorder preceding eclampsia, although it is now known that eclamptic seizures are only one of the several potential complications of the disease. Eclamptic seizures usually occur as a later complication of severe preeclampsia, but may also arise without any prior signs of sever disease.
How is eclampsia treated?
Magnesium sulfate (given intravenously) is the treatment of choice for severe preeclampsia – to prevent eclampsia – or after eclampsia develops to prevent recurrence. Many, but not all, doctors will also treat every preeclamptic patient with magnesium sulfate during labor, even when the disease appears mild. Magnesium treatment is generally continued for 24-48 hours after the last seizure. You may receive magnesium sulfate in an intensive care unit or a labor and delivery unit. While magnesium is given you will be observed closely, receive intravenous fluids, and may have a catheter placed in your bladder to measure urine output.
Magnesium sulfate can be used by a skilled health care provider with appropriate support facilities. Overdoses can occur, especially in the context of impaired kidney function.
Magnesium sulfate has often been compared to Epsom salts, but ingesting Epsom salts, and magnesium vitamin supplements have not been shown to prevent maternal death due to eclamptic seizures. Levels achieved with oral therapy are not sufficient to prevent seizures.
What is HELLP syndrome?
HELLP syndrome is one of the most severe forms of preeclampsia and occurs in 5-12% of preeclamptic patients. It can lead to substantial injury to the mother’s liver, a breakdown of her red blood cells and lowered platelet count. HELLP stands for: hemolysis, elevated liver enzymes, and lowered platelets. HELLP syndrome may initially be mistaken for the flu or gallbladder problems, because the pains may feel similar and it can occur before the classic symptoms of preeclampsia appear.
The most important thing to remember with HELLP syndrome and preeclampsia is to listen to your body. If you don't feel right or have any of the symptoms, contact your healthcare professional immediately.
For more information about HELLP syndrome, read this special health information.
Who gets preeclampsia?
Preeclampsia and other hypertensive disorders of pregnancy occur in 5-8% of all pregnancies of women who have no known risk factors (see below). It is more apt to occur during the first pregnancy. The most significant risk factors for preeclampsia are:
What causes preeclampsia?
The cause (etiology) of preeclampsia remains unknown. Numerous proposed theories have led to various attempts at prevention and intervention strategies, none of which have proven to be overwhelmingly successful. There is, however, general agreement that the placenta plays a key role in preeclampsia, and women with chronic hypertension and certain metabolic diseases like diabetes are more susceptible. Obesity is another major risk factor – one that is perhaps modifiable.
Speak to your physician about your risks, and what you can do to minimize them, but recognize that no definitive answers to the cause or causes of preeclampsia yet exist.
There are a number of theories about the initiating cause of preeclampsia and the descriptions in research articles can be difficult to understand. We’ve included in the chart below some current medical terms for the various theories and a layperson’s interpretation. A more detailed article about the potential causes is also available here.
|Medical Description||Layperson's Description|
|Uterine ischemia/ underperfusion||Insufficient blood flow to the uterus|
|Inflammation||Excessive maternal inflammatory response to pregnancy|
|Angiogenesis||Factors regulating the formation of new blood vessels in the placenta are overproduced which in turn affect the blood vessel health in the mother leading to hypertension and kidney damage.|
|Prostacyclin / thromboxane imbalance (ASA)||Disruption of the balance of hormones that maintain the diameter of the blood vessels.|
|Endothelial activation and dysfunction||Damage to the lining of the blood vessels that keeps fluid and protein inside the blood vessels, keeps blood from clotting, and regulates elasticity of the blood vessel.|
|Calcium deficiency||Calcium helps maintain blood vessels and normal blood pressure. A deficiency may lead to increased blood pressure.|
Hemodynamic vascular injury
|Injury to the blood vessels due to excessive blood flow or pressure. For example one might compare the condition to what would happen if a garden hose was hooked up to a fire hydrant.|
|Preexisting maternal conditions||The mother has undiagnosed high blood pressure or other preexisting problems such as diabetes, lupus, sickle cell disorder, hyperthyroidism, kidney disorder, etc.|
|Immunological Activation||The mother’s immune system mistakenly responds as if damage has occurred to the blood vessel and in trying to fix the "injury" actually makes the problem worse.|
|Nutritional Deficiencies||Insufficient protein, excessive protein, fish oil, vitamin D, and other diet factors.
|Obesity||High body mass index (BMI) is linked to the genetic tendency for high blood pressure, diabetes and insulin resistance, and also to the effect of obesity on the inflammatory system.|
|Genetic Tendency||The hereditary transmission of inherited characteristics among family members.|
What does preeclampsia do?
Preeclampsia can cause your blood pressure to rise and put you at risk of brain injury. It can impair kidney and liver function, and cause blood clotting problems, pulmonary edema (fluid on the lungs), seizures and, in severe forms or left untreated, maternal and infant death. Preeclampsia affects the blood flow to the placenta, often leading to smaller or prematurely born babies. Ironically, sometimes the babies can be much larger, but scientists are not certain that preeclampsia was the cause. While maternal death from preeclampsia is rare in the developed world, it is a leading cause of illness and death globally for mothers and infants.
How does preeclampsia affect pregnancy?
Preeclampsia is often silent, showing up unexpectedly during a routine blood pressure check and urine test. In cases like this, if the baby is considered “term” (on or after 37 weeks) and the growth rate considered normal, the baby is delivered, and the mother monitored and sent home as usual.
The impact of preeclampsia is more profound if it occurs earlier in the pregnancy, or in a woman who had high blood pressure before pregnancy. Care providers may recommend time off work, bed rest, medication and even hospitalization to keep the blood pressure under control. Keeping the baby in-utero as long as possible, assuming growth continues, is preferred for the long-term health of the baby.
Unfortunately, the only "cure" for the disease begins with delivery of the baby and placenta, which is sometimes recommended before the pregnancy goes to term in the best interest of the mother. Doctors may prescribe anti-hypertensive medications. If the blood pressure cannot be managed with medication and treatment, and the mother's and/or baby’s health is at risk, the mother may be given steroids to aid the maturation of the infant's lungs prior to delivering the baby.
When does preeclampsia occur in a pregnancy?
Preeclampsia can appear at any time during pregnancy, delivery and up to six weeks post-partum, though it most frequently occurs in the final trimester and resolves within 48 hours of delivery. Preeclampsia can develop gradually, or come on quite suddenly, even flaring up in a matter of hours, though the signs and symptoms may have gone undetected for weeks or months.
Can preeclampsia occur after the baby is born?
In some instances, preeclampsia does not appear until during the delivery, or the 48 hours that follow, but it has been known to occur up to six weeks post-partum. While obviously not dangerous for the baby, post-partum preeclampsia is still critical for the mother. Nearly 80% of women who die from Preeclampsia die post-partum. Sleep deprivation, post-partum depression, more attention on the newborn, and a lack of familiarity with normal post-partum experiences all contribute to more easily ignoring or missing indicators of a problem. Any of the signs and symptoms described above should be cause for concern, and you should immediately contact your health care provider if you experience any of them.
How does preeclampsia affect the baby?
Worldwide, preeclampsia is responsible for up to 20% of the 13 million preterm births each year. Although U.S. research is scant on this topic, this same rate applied in the U.S. means preeclampsia is one of the leading known causes of prematurity, responsible for as many as 100,000 of the total 500,000 premature births annually in the US.
A baby is considered premature in developed countries if born prior to 37 weeks gestation (almost one month early), but most severe prematurity issues occur to babies born earlier than eight months gestation (approximately 32 weeks). The impact of prematurity can have greater consequences somewhat later in developing countries, because those countries often lack the resources that preemies require.
Preterm birth has a wide range of consequences from fairly inconsequential to major neurologic damage. Some babies may spend only a day or two under close observations while others may spend the first months of their life in the Neonatal Intensive Care Unit (NICU) causing a great deal of emotional and financial stress on the family. More information about preterm birth can be found at the March of Dimes website.
Intrauterine Growth Restriction (IUGR)
Reduced blood flow to the placenta restricts the supply of food to the baby and can result in a shortage of food and result in malnourishment – a condition called intrauterine growth restriction (IUGR). As a result, the baby may be smaller for its gestational age. Ultrasounds can help identify IUGR. Many babies who suffer from IUGR can catch up on their growth within a few months, although recent research suggests that growth restricted infants are more prone to adult diseases including diabetes, congestive heart failure and hypertension. Of the 30 million IUGR infants born worldwide each year, 15% (4.5 million) are associated with preeclampsia.
Mother’s shouldn’t blame themselves or poor nutrition for IUGR, because it is caused by a failing placenta and not the mother’s diet. You could be eating all of the right things, but if the placenta is not capable of passing nutrients along, your baby’s growth will suffer.
The baby survives in the womb by receiving nutrients and oxygen through the placenta. Preeclampsia compromises the placenta and the baby’s body begins to restrict blood flow to its limbs, kidney and stomach in an effort to preserve the vital supply to the brain and heart. Should the baby’s oxygen reserve become depleted, (as the placenta detaches or dies) the baby’s body can extract energy from its fuel supplies without oxygen. However, this process generates lactic acid. If too much lactic acid builds up, the baby will develop “acidosis” and become unconscious and stop moving. Delivery is essential at this point.
Infant death is one of the most devastating consequences of preeclampsia. In the U.S., approximately 10,500 babies die from preeclampsia each year and an estimated half a million worldwide. Many countries do not have the means to keep a premature baby alive, so the rate of neonatal death in these countries is therefore much higher.
Stillbirths from preeclampsia, babies that die in utero after 20 weeks of gestation, number between 1,000 and 2,200 in the U.S. Stillbirths are much less likely to occur with mild preeclampsia than they are with more severe variants such as HELLP syndrome or preeclampsia superimposed on chronic hypertension.
Approximately 20% of Preeclampsia Foundation members have lost at least one baby. The disease can manifest in a very short time. You can have a normal prenatal appointment in the morning and lose your baby by the afternoon. We therefore encourage your to err on the side of caution and contact your doctor immediately if you experience signs of preeclampsia.
Ongoing life challenges
Preeclampsia has been linked to a host of lifelong challenges for infants born prematurely, among them learning disorders, cerebral palsy, epilepsy, blindness and deafness. With prematurity also comes the risk of extended hospitalization, small gestational size and the interruption of valuable bonding time for families. Prematurity stresses a family unit, and this stress is compounded when the mother is also ill.
An integrated system of maternal and newborn care can reduce some of these deaths. This includes diagnosing preeclampsia early, monitors the baby’s condition, using magnesium sulfate to prevent maternal seizures and possibly confer neurological protection on the baby, safely managing early delivery when needed, and providing needed care for pre-term newborns. However, we ultimately need more research. We need to find a cure.
What is the cure?
Currently, the only “cure” to preeclampsia begins with delivery of the baby and placenta. When preeclampsia develops, the mother and her baby are monitored carefully. There are medications and treatments that may prolong the pregnancy, which can increase the baby's chances of health and survival. Once the course of preeclampsia has begun, it cannot be reversed and the health of the mother must be constantly weighed against the health of the baby. In some cases, the baby must be delivered immediately, regardless of gestational age, to save the mother's and/or baby's life.
What can we do about preeclampsia?
Right now, early diagnosis through simple screening measures and good prenatal care can predict or delay many adverse maternal outcomes of preeclampsia. Prompt treatment saves lives. Research is beginning to provide insight into some of the molecular abnormalities present in preeclamptic women and it is hoped that these recent discoveries may lead to development of a cure.
Researchers suggest there are probably several different variables, some maybe genetic in origin, that predispose a woman to getting preeclampsia and that a preventive or curative therapy for one woman may not work for all women. Although the Preeclampsia Foundation helps fund research, much more is needed. Sadly, preeclampsia is still one of the lowest funded research areas in terms of what health economists call Disability Adjusted Lost Years (DALYs), and we think the pregnant woman deserves a better deal. Policymakers, scientific investigators, health care professionals and patients need to work together to bring the information we already have to those who need it most and to drive greater awareness and resources to this devastating problem. To contribute to our research and education programs, please make a contribution here or call us to discuss your interests in a major gift.
Will I get preeclampsia in a subsequent pregnancy?
If my first pregnancy was normal...
If you had a normal first pregnancy, your risk of having preeclampsia in the next pregnancy is very low. However, if you have other risk factors (such as advanced maternal age, excess weight, family history of hypertension), you should be watchful and alert to early warning signs.
Back to top
If I had preeclampsia in my first or an earlier pregnancy...
There has been some research looking at the rate of reoccurrence in subsequent pregnancies, but more is needed. The findings suggest the risk of having it again is approximately 20%, however experts cite a range from 5-80%, depending on when you had it in a prior pregnancy, and how severe it was. If you had preeclampsia during your first pregnancy, you may get it again. While repeat occurrence is often milder, no one can predict for sure. You should be watched carefully after a preeclamptic pregnancy.
The risk of preeclampsia increases if you have any of the risk factors mentioned above, or have developed chronic hypertension or diabetes since your previous pregnancy, or if you are having IVF, twins or other multiples.
If I had it in a first but not a second...
Although you did not have preeclampsia during a second pregnancy, you may still be at risk for reoccurrence during a subsequent pregnancy. Make sure you review your history of preeclampsia with your care provider. As with all pregnancies, awareness of and responsiveness to warning signs and symptoms is very important.
If I have been advised against getting pregnant again...
Some preeclampsia experiences are traumatic for the family, friends and doctors who cared for you as well. Sometimes a doctor will advise against a future pregnancy because they don’t know what will happen and fear for your safety and well-being. We advise all women in this position to seek a pre-pregnancy consultation with a maternal-fetal medicine doctor who specializes in preeclampsia and related disorders. They can review your medical history, evaluate potential underlying disorders, and give you a more clear idea of your risks. Even a well-meaning obstetrician may not have the experience to provide this advice. While no individual will be able to decide for you, they can, however, help you weigh your options.