Pre eclampsia, sometimes called toxemia, is a unique and often dangerous condition that only occurs during pregnancy. Most experts define PRE ECLAMPSIA as an elevation in blood pressure in a pregnant woman of 140/90, with protein in the urine, or swelling (edema) of the feet, hands, and/or face. The condition occurs more commonly during first pregnancies, with twins or triplets, in very young or older women, and when a woman has had pre eclampsia with previous pregnancies. In general, about 10-15% of women get this condition during their first pregnancy, while about 7% or women who have previously had children develop pre eclampsia with later pregnancies. Interestingly, there is a strong tendency for pre eclampsia to run in families. An understanding of this common and complex medical condition will help pregnant women and their partners who develop pre eclampsia.
Medical researchers have been diligently trying to discover what causes pre eclampsia. Much of the frustration doctors have treating this condition is that we do not know what causes it. A number of theories have been proposed, including abnormalities with the placenta (afterbirth), a problem with the immune system, a hereditary (genetic) link, and defects of the blood clotting mechanism. Regardless, we do know that pre eclampsia causes changes within the blood vessels that cause them to “leak” into tissue. The leaking causes swelling of the tissues, which we see as edema. It also causes leaky kidney tissues, so that protein spills into the urine, which we can see when we test the urine. If the pre eclampsia becomes more severe, swelling can occur in the liver, leading to severe pain under the right rib cage, and, in rare cases, rupture of the liver with hemorrhage. Sometimes swelling can occur in the brain, leading to seizures, which we call “eclampsia.”
Since we don’t know the exact cause of pre eclampsia, we do not know how to prevent it. Medical students are sometimes asked “how do you prevent pre eclampsia?” The only right answer is “birth control,” since this condition only affects pregnant women, and there are no other ways to prevent the condition. Calcium supplementation does not seem to help, as was once believed, although some doctors still prescribe it. Calcium is generally safe during pregnancy. pre eclampsia cannot be prevented by decreasing salt intake or increasing protein in the diet.
Pre eclampsia is most common towards one’s due date, although it can uncommonly occur earlier in pregnancy. Doctors and midwives tend to see pregnant patients more often during the last month or so of their pregnancy, and part of the reason we do this is to check for elevated blood pressure or protein in the urine. We are less bothered by edema, since 8 out of 10 pregnant women get this, which makes this a rather normal finding in pregnancy. However, elevated blood pressure of greater than 140/90 and protein in the urine are not normal, so we get very concerned about these findings. When patients develop high blood pressure and protein in the urine, we become concerned about pre eclampsia. In many cases blood tests are ordered to rule out problems with anemia, blood clotting, liver damage, and kidney damage. Sometimes a 24-hour urine is ordered, where the patient collects her urine for 24 hours so that it can be checked for the total amount of protein. If pre eclampsia is diagnosed, treatment may consist of bed rest (especially with the patient lying on one side or the other to increase blood flow to the baby), or hospitalization, or even induction of labor (“taking the baby”) to prevent dangerous complications. The decision to induce labor versus suggesting bed rest depends on how far along the patient is, and how the baby is doing as indicated by fetal heart rate and ultrasound tests. It also depends on whether or not the pre eclampsia is mild or severe, as discussed shortly. Sadly, if the patient has severe PRE ECLAMPSIA that is worsening despite bed rest and other therapies, her doctors may strongly advise induction of labor, even if the baby is very premature. In some cases the baby is delivered even though the doctors know he or she will die from prematurity, in order to save the mother’s life. This is a tragic situation that affects the mother, her partner, and every member of the medical team caring for her. Sometimes various medications are given to prevent seizures. This depends on what part of the world one lives in, but in the U.S., most doctors give magnesium sulfate (called “Mag” or Mag sulfate” in medical shorthand). This medication produces a warm or flushed feeling, along with some drowsiness. It helps prevent seizures (eclampsia), which can be dangerous for the mother or baby.
If bed rest is prescribed, the blood pressure and urine protein will be checked often. Sometimes it is safe to remain on bed rest at home, while in other cases hospitalization is necessary. Regardless, if the blood pressure becomes too high, delivery must be induced to prevent seizures, liver damage, kidney damage, or bleeding. Patients on bed rest should immediately report any spots in front of the eyes (which may mean brain swelling), severe pain under the right ribcage (which may indicate liver swelling), bleeding from the gums or elsewhere (which may mean problems with the body’s ability to form blood clots), seizures, severe abdominal pain (which can mean bleeding around the placenta, called an abruption), or decreased movement of the baby. All of these require immediate evaluation.
Pre eclampsia is categorized as either mild or severe. Most cases are mild, but some are severe, and in unusual cases are life-threatening. Severe pre eclampsia consists of blood pressure that is 160/110 or higher, blood clotting problems, fluid around the mother’s lungs, liver pain, huge amounts of protein in the urine, lack of urine output, or HELLP syndrome. HELLP stands for damaged blood cells (Hemolysis), Elevated Liver tests, and Low Platelets. The damaged blood cells may lead to edema and anemia, while the elevated liver tests occur because of swelling around the liver. If a liver hematoma develops, it can burst, causing unbelievable hemorrhage. Thankfully, this is rare, as many women die when the liver ruptures, while the one’s that live sometimes require up to 100 units of transfused blood. Low platelets is also called thrombocytopenia in medial lingo. Platelets help the blood clot, and when the level of platelets in the body becomes dangerously low, severe bleeding can develop. This may require many units of blood transfusion and in some cases the patient may die from bleeding that cannot be stopped. HELLP syndrome is diagnosed by blood tests and careful monitoring, and is treated by delivering the baby. Sometimes dialysis for the kidneys, blood transfusion for low platelets, or high doses of steroids are used to treat this condition. HELLP syndrome should be managed in a high-risk hospital, not at home. Thankfully, HELLP syndrome only occurs in about 2-10% of cases of PRE ECLAMPSIA.
Women who have had pre eclampsia often ask their doctors if they are at increased risk of developing this condition in later pregnancies. Roughly, about 20%-25% of women with pre eclampsia will develop this condition with later pregnancies. About 5% of women with HELLP syndrome can expect to develop this condition with subsequent pregnancies. When seizures develop during pre eclampsia, it is called eclampsia. The chance of this occurring in later pregnancies is only about 1-2%.
In summary, pre eclampsia is usually mild and treated by bed rest or delivery of the baby, but in some cases severe disease can develop. This requires treatment by a doctor experienced in treating complicated (high-risk) pregnancies, usually in a larger hospital or medical center. High blood pressure during pregnancy can be fatal for the mother and baby, so it requires careful monitoring. Fortunately, modern medical care has progressed to the point where pre eclampsia can be monitored and treated appropriately, usually without causing serious harm. As always, discuss any questions you may have with your doctor.
D. Ashley Hill, M.D.
Department of Obstetrics and Gynecology
Florida Hospital Family Practice Residency