Preeclampsia is a severe condition that occurs in the 2nd half of pregnancy which is characterized by a sudden onset of high blood pressure with edema (a type of swelling), and/or abnormal amounts of protein in the urine. It is called preeclampsia because it occurs before (which is what "prae" means in Latin) eclampsia.
WHAT IS ECLAMPSIA?
Eclampsia is a rare, but serious complication of pregnancy characterized by an attack of convulsions (abnormal, severe, involuntary muscle movements) that are not caused by other conditions of the brain (such as bleeding in the brain) in a woman with moderate or severe (but not mild) preeclampsia.
WHAT ARE OTHER SIGNS AND SYMPTOMS OF PREECLAMPSIA?
The early signs and symptoms of preeclampsia are high blood pressure, blurry vision, abnormal amounts of protein in the urine, and edema (a type of swelling) of the face and hands. Other symptoms of preeclampsia include headache, nausea, pain in the belly, a lesion (abnormality) in the kidneys, and vomiting.
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WHAT IS NORMAL VERSUS HIGH BLOOD PRESSURE?
A normal blood pressure level is 120/80 (120 over 80). Blood pressure is measured in millimeters of mercury, which is commonly abbreviated as mm Hg. A millimeter is a very small unit of length equal to .0394 inches. Mercury is a metal element that is liquid at room temperature. Blood pressure is measured by assessing the length of mercury on a type of ruler, which is attached to a pump that is used to inflate a cuff placed around the arm. The cuff is pumped up to the point that it blocks off the blood supply through an artery (a large blood vessel that carries blood away from the heart) below the cuff. After the blood supply is blocked off, air is slowly let out of the cuff and the millimeters of mercury are measured.
The top number in blood pressure measurement (120 in the example above) is known as systolic blood pressure. Systolic blood pressure is the pressure of the blood when the heart contracts (pumps).
The bottom number in blood pressure measurement (80 in the example above) is known as diastolic blood pressure. Diastolic blood pressure is the pressure of the blood when the heart is at rest between beats (not pumping). Abnormal blood pressure, as it relates to mild and severe preeclampsia is described below.
WHAT IS MILD PREECLAMPSIA?
Mild preeclampsia is diagnosed if one or more of the following signs develop after the 20th week of pregnancy:
1. Changes in blood pressure to 140/90 or more (normal blood pressure is 120/80). See discussion above to understand the terms related
to blood pressure. Another change in blood pressure can be an increase in 30 mm Hg of systolic blood pressure and/or an increase in 15 mm Hg of diastolic blood pressure, compared to the blood pressure level early in pregnancy. The changes in blood pressure must be observed on two separate occasions at least 6 hours apart.
2. Edema (a type of swelling), as identified by weight gain of more than 3.3 pounds in a month in the second trimester (months 3 to 6) of pregnancy, or more than 1.1 pounds in a week in the third trimester (months 6 to 9) of pregnancy.
3. Abnormal levels of protein in the blood. This is often the last sign to appear in mild preeclampsia.
4. Compare these criteria to severe preeclampsia, discussed below.
WHAT IS SEVERE PREECLAMPSIA?
Severe preeclampsia is diagnosed if one or more of the following signs develop after the 20th week of pregnancy:
1. Changes in blood pressure to 160/110 or more (normal blood pressure is 120/80). See the discussion two questions above to understand
the terms related to blood pressure.
2. Edema (a type of swelling), as identified by weight gain of more than 2 pounds in a few days to a week.
3. Cyanosis, which is a bluish color of the skin caused by too much hemoglobin or problems with the structure of the hemoglobin.
4.Hemoglobin is a substance in the blood that carries oxygen to the cells in the body from the lungs.
5. The amount of protein in the urine being greater than 5 grams in 24 hours. A gram is a very small unit of weight.
6. Disorders of the blood vessels in the brain.
7. A buildup of fluid in the lungs.
8. Disorders of the eye.
9. Compare these criteria to mild preeclampsia, discussed above.
WHAT ABOUT MODERATE PREECLAMPSIA?
Although there are no official criteria for moderate preeclampsia, some health care providers use the term to describe signs and symptoms that are somewhere between mild and severe preeclampsia.
WHAT PROBLEMS DO PREECLAMPSIA COMMONLY CAUSE?
Preeclampsia commonly causes poor kidney function, irritability of the brain and/or spinal cord, hyperactive reflexes, an increase in the number of red blood cells, and changes in fluids and electrolytes in the body. Electrolytes are chemical substances that are able to conduct electricity after they are melted or dissolved in water. Metabolism (a chemical process in the body by which food is broken down and changed to energy) can also be abnormal in preeclampsia. As an example of abnormal metabolism, the amount of nitrogen (a type of gas) that is excreted (released from the body as waste) through urine or feces (poop), is higher than the amount of nitrogen taken into the body through food. When this happens, it is an indication that tissues in the body are wasting away.
WHAT ARE COMPLICATONS OF PREECLAMPSIA?
Serious complications of preeclampsia include damage to the eyes, changes in cells that make up the liver, bleeding in the brain, a buildup of fluid in the lungs, hemolysis (a breakdown of red blood cells), and hypofibrinogenemia. Hypofibrinogenemia is a decrease of a substance in the body known as fibrinogen that causes bleeding to stop. Poor nourishment of the developing baby and low birth weight can be caused by preeclampsia. Placental abruption can also occur, which refers to when the placenta separates in a pregnancy of 20 weeks or more. The placenta is an organ in the uterus (a hollow organ in which a baby develops) that links the blood supply of the mother to the developing baby and by which the baby can release wastes. It is possible for preeclamapsia to lead to death of the mother or developing baby.
WHEN DOES PREECLAMPSIA OCCUR?
Preeclampsia usually occurs after the 20th week of pregnancy. However, it may develop before this time in the presence of trophoblastic disease (disease of the trophoblast, a layer of cells that contribute to the formation of the placenta). The placenta is an organ in the uterus (a hollow organ in which a baby develops) that links the blood supply of the mother to the developing baby and by which the baby can release wastes.
WHO TENDS TO GET PREECLAMPSIA?
Preeclampsia tends to occur in women who are having their first pregnancy. It also tends to occur in women under age 25 and over age 35. Women having twins are also likely to develop preeclampsia. Interestingly, women who live in the southeastern United States are more likely to develop preeclampsia than women who live in other parts of the country. As the age of the developing baby increases so do the chances of developing preeclampsia.
Women who have the following conditions also tend to develop preeclampsia: high blood pressure, kidney disease, and diabetes mellitus. Diabetes mellitus is a condition in which the body does not produce enough insulin, a chemical substance that helps absorb glucose (a type of sugar) into cells for energy and into the liver and fat cells for storage. Women with an abnormal mass in the uterus (a hollow organ in which the baby develops) known as a hydatidiform mole are more likely to develop preeclampsia. Also, women are more likely to develop preeclampsia is they have a condition known as hydramnios, in which there is an excess of amniotic fluid (a fluid that surrounds the developing baby).
HOW OFTEN DOES PREECLAMPSIA OCCUR?
Preeclampsia occurs in about 5% to 7% of all pregnancies. Thus, it is a relatively common occurrence during pregnancy.
HOW IS PREECLAMPSIA TREATED?
To reduce and prevent high blood pressure, blood pressure reducing medications are given. The woman is also confined to bed rest in mild cases of preeclampsia. Sedation (causing a state of calm in the body), drinking fluids, and eating a well balanced diet that is high in protein, calories, and essential nutrients (healthy substances) also tends to help control the problem. To prevent convulsions from occuring, drugs known as anticonvulsants (such as magnesium sulfate) may be administered. If the woman is close to delivering a baby or it appears that eclampsia is going to develop very soon, the doctor may cut open the belly to deliver the baby quicker because the signs and symptoms usually go away once the baby is born.
WHAT CAUSES PREECLAMPSIA?
After thousands of investigations and about 100 years of research, the cause of preeclampsia is not fully understood.
WHAT ELSE IS PREECLAMPSIA KNOWN AS?
Preeclampsia is also known as toxemia of pregnancy.
HOW DO I FIND OUT MORE INFORMTION ON PREECLAMPSIA?
An excellent website is The Action on Pre-Eclampsia Home Page, which provides support, and promotes and publicizes relevant research. Another great website with a support group, stories, diaries, memorials, and more is the Pre-Eclampsia website.
WHAT IS THE ORIGIN OF THE WORD, PREECLAMPSIA?
Preeclampsia comes from the Latin word "prae" meaning "before," the Greek word "ek" meaning "out," and the Greek word "lampein" meaning "to flash." Put the words together and you get "before flashing out." Flashing out is a term that refers to eclampsia, described above.