Eclampsia: A Severe Complication of Pregnancy

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We have discussed the pregnancy complication known as preeclampsia a few times, here on The Pulse, but what about the condition for which PREemclampsia is a precursor, namely eclampsia. Let’s talk about eclampsia as a condition more severe than the more common preeclampsia, a complication that can develop after 20 weeks of gestation. Preeclampsia features high blood pressure (more than 140 mm Hg systolic or more than 90 mm Hg diastolic), along with either kidney problems that cause proteinuria (protein in the urine at levels than 300 mg per 24 hours), or with problems with other internal organs. Preeclampsia is defined as severe, if the systolic pressure climbs higher than 160 mm Hg, or if the diastolic pressure climbs higher than 110 mmHg. If seizures develop in a woman with the high blood pressure and the internal organ dysfunction of preeclampsia, then doctors will use the word eclampsia.

Although preeclampsia is fairly common, developing in 2 – 10 percent of pregnancies, eclampsia is more rare; when preeclampsia is not treated, approximately 1 out of 200 cases develop into eclampsia. Factors that increase your risk of developing preeclampsia and eclampsia include older maternal age (greater than 35 years), having a history of preeclampsia or eclampsia in the family, having suffered eclampsia or preeclampsia in a previous pregnancy, obesity, nulliparity (you have never given birth before), high blood pressure prior to pregnancy, type 1 diabetes, multiple fetuses (twin or higher pregnancy), systemic lupus erythematosis (SLE, “lupus”), kidney disease, a condition called antiphospholipid antibody syndrome, and if you are not Asian and carrying a male fetus.

Eclampsia is diagnosed if a woman develops seizures in addition to meeting requirements for diagnosis of preeclampsia. This means blood pressure in the range of 140 – 160 mmHg systolic or 90 -110 mmHg diastolic, recorded on two separate readings, taken at least 4 hours apart, and that is a new condition for the woman (as opposed to a continuation of pre-pregnancy or early pregnancy high blood pressure condition). The diagnosis also requires trouble with an organ, or with platelets, the cell-like particle in the blood that help form blood clots. Usually the organ trouble is protein in the urine, meaning a problem with the kidneys, but it can involve a different organ. If the woman’s blood pressure measures in the severe range (>160 systolic, >110 diastolic), doctors are not supposed to wait the 4 hours to take a second reading, nor does there need to be any evidence of an organ problem. Rather, the condition is assumed to be preeclampsia (eclampsia if seizures are also present) and is treated based on this assumption. Electroencephalography (EEG), which measures electrical activity in the brain, can be used to confirm the onset of seizures. However, if a pregnant woman comes into the emergency department or delivery room with convulsions (sudden, irregular movements of limbs and other parts of the body) and high blood pressure, doctors will already know that she has eclampsia. In addition to EEG, diagnosis also is supported with urine samples to test for protein, plus there are blood tests aimed at evaluating function of organs, such as the kidneys and liver. A complete blood count also will be performed to evaluate for anemia and for a low platelet count. A blood sample also enables a blood smear, which can reveal broken red blood cells. The level of oxygen in your blood will be tested, plus the fetus will be monitored with ultrasonography. If a clot or bleeding in the brain is suspected, brain imaging will be obtained with magnetic resonance imaging (MRI) or computed tomography (CT).

Eclampsia and severe preeclampsia are extremely dangerous for both a mother and her fetus. In addition to presenting with seizures, eclampsia can lead to bleeding in the brain, a type of stroke, particularly if blood pressure is in the severe range (systolic above 160 mmHg or diastolic above 110 mmHg). Stroke also can develop, due to a clot in the brain. Many women with eclampsia also have a condition called HELLP syndrome, which is characterized by red blood cells breaking apart (hemolysis) and the number of platelets (clot forming cells) in blood dropping down, leaving the woman prone to hemorrhage (severe bleeding). Numerous other complications of eclampsia can develop in the brain, retina of the eye, and liver, kidney failure, various problems in the lungs requiring a ventilator, and the placenta can detach prematurely from the uterus. Babies born to a mother with eclampsia have an elevated risk of various disorders, including cerebral palsy and also are at elevated risk of neonatal death.

Seizures of eclampsia are treated and prevented with a medication called magnesium sulfate (MgSO4), given by either intramuscular (IM) or intravenous (IV) route. MgSO4 is the first medication given in attempts to stop seizure. If it doesn’t work, then a benzodiazepine drug (lorazapam or diazepam) or another type of anti-seizure drug is given, and then MgSO4 is given to additional seizures. Is also given to women with severe preeclampsia to prevent eclamptic seizures from occurring in the first place. Eclamptic women are also given any of a variety of blood-pressure lowering drugs. These drugs all have possible risks for the fetus, but generally the fetus is at higher risk from being in the womb of a mother who has eclampsia. Another major category of drugs is corticosteroids, which are generally safe in pregnancy. These are given to accelerate maturation of the fetal lungs so that the fetus can be delivered early, which usually resolves the eclampsia. The main treatment for eclampsia is simply to deliver the baby as early as possible, which usually means at 34 weeks gestation (6 weeks early).

David Warmflash
Dr. David Warmflash is a science communicator and physician with a research background in astrobiology and space medicine. He has completed research fellowships at NASA Johnson Space Center, the University of Pennsylvania, and Brandeis University. Since 2002, he has been collaborating with The Planetary Society on experiments helping us to understand the effects of deep space radiation on life forms, and since 2011 has worked nearly full time in medical writing and science journalism. His focus area includes the emergence of new biotechnologies and their impact on biomedicine, public health, and society.

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