Pre-eclampsia

Every visit to your doctor or midwife starts with the same routine, a blood pressure check, weight check, and the testing of a urine sample. These simple tests are designed to detect pre-eclampsia.

Pre-eclampsia (also known as toxemia or pregnancy-induced hypertension) is a disease that affects only pregnant women. This disease is much more common in first pregnancies, and is more likely to affect women at either end of their reproductive years-that is, both very young and older first-time mothers. Pre-eclampsia was originally characterized by elevated blood pressure, edema (swelling), and protein in the urine. As our understanding of this condition has grown, additional signs and symptoms have been identified. The most important of these is extreme sensitivity of the nervous system, which may cause seizures. Pre-eclampsia can also cause abnormalities in blood clotting and liver function.

Blood pressure measurement is expressed with two values, one value "over" another value. The upper number is the systolic pressure, and the lower number is the diastolic pressure. A typical blood pressure for a pregnant woman might be 110/70, or 110 "over" 70. If the diastolic pressure (bottom number) rises into the 90s and is sustained at that level, the possibility of pre-eclampsia must be considered. A sustained diastolic pressure above 100 is usually indicative of a severe case of pre-eclampsia.

It is important to remember, however, that a diagnosis of pre-eclampsia can only be made by comparing changes in a pregnant woman's blood pressure with her own blood pressure earlier in the pregnancy (preferably the first trimester). What is normal for one woman may be abnormal for another.

In the days before pre-eclampsia could be treated, serious complications often developed. These included seizures, strokes, and kidney damage. Today, these complications are almost never seen. Pre-eclampsia is usually diagnosed early and treated effectively. For example, women who have moderate to severe symptoms may be treated with magnesium sulfate administered through an intravenous line; this treatment will usually prevent seizures.

If your doctor or midwife has any reason to believe that you might be developing pre-eclampsia, you will get a thorough physical exam and a variety of blood tests that can give you more information about the course of the disease. You will also be advised about certain symptoms to watch for, including headache, blurry vision, and upper abdominal pain. These symptoms may indicate that your blood pressure is too high. If necessary, your practitioner may prescribe drugs, such as hydralazine, to lower your blood pressure.

Your practitioner will also recommend bed rest on your left side. In mild cases of pre-eclampsia, bed rest may be all that is needed to lower your blood pressure until delivery. The reason the left side is preferred is that this position takes the weight of the uterus off the major blood vessels that lie behind it, allowing maximum blood flow to the uterus and placenta.

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