Preeclampsia is high blood pressure that is accompanied by protein in the urine and that develops after the 20th week of pregnancy. Eclampsia is seizures that occur in women with preeclampsia and that have no other cause.
About 3 to 7% of pregnant women develop preeclampsia (toxemia of pregnancy). In preeclampsia, an increase in blood pressure is accompanied by protein in the urine (proteinuria). Without treatment, preeclampsia can suddenly cause seizures (eclampsia). Eclampsia occurs in 1 of 200 women who have preeclampsia. If not treated promptly, eclampsia is usually fatal.
Preeclampsia (with or without eclampsia) develops after the 20th week of pregnancy and usually before the end of the first week after delivery. One fourth of the cases occur after delivery, usually within the first 4 days but sometimes up to 6 weeks after delivery.
This syndrome develops in 1 or 2 of 10 women with severe preeclampsia or eclampsia. The HELLP syndrome consists of the following:
Most pregnant women with this syndrome have high blood pressure and protein in the urine, but some have neither.
The cause of preeclampsia is unknown. But it is more common among women who
Some women have no symptoms. In others, preeclampsia causes fluids to accumulate (edema), particularly in the hands and face and around the eyes but also in the feet. Rings may no longer fit. Women may gain excess weight.
Tiny red dots (petechiae) may appear on the skin, indicating bleeding in the skin. Women may feel jittery.
If severe, preeclampsia can damage organs, such as the brain, kidneys, lungs, heart, or liver. Then women may have headaches, distorted vision, confusion, difficulty breathing, pain in the upper right part of the abdomen (over the liver), vomiting, or other symptoms. If the HELLP syndrome develops, it may cause similar symptoms. The HELLP syndrome can develop before symptoms of preeclampsia appear. A pregnant woman who has a new headache that does not resolve with acetaminophen or within 24 hours should call her doctor.
Preeclampsia may cause few noticeable symptoms for a while, then suddenly worsen and cause seizures (eclampsia).
Babies may be small because the placenta malfunctions or because they are born prematurely. Babies of women with preeclampsia are 4 or 5 times more likely to have problems soon after birth than babies of women who do not have this complication.
Rarely, preeclampsia may cause the placenta to detach too soon (called placental abruption—see Placental Abruption (Abruptio Placentae)).
Doctors diagnose preeclampsia when a woman has the following:
Doctors do blood and urine tests to confirm the diagnosis, to determine how severe preeclampsia is, and to check for organ damage. Doctors also check the fetus's heart rate. Ultrasonography is done to check other signs of the fetus's well-being, such as movements, breathing, and muscle tone (see Sidebar 1: Monitoring the Fetus).
Delivery is the best treatment, but doctors must weigh the risk of an early delivery against the severity of preeclampsia. Delivery is usually done as soon as possible in the following situations:
If delivery can be delayed in pregnancies of 32 to 34 weeks, women are given corticosteroids to help the fetus's lungs mature. If the pregnancy has lasted longer than 36 or 37 weeks and preeclampsia is mild, the baby is delivered.
If mild preeclampsia develops early in the pregnancy, women are advised to modify their activities. For example, they are advised to stop working if possible, stay seated most of the day, and avoid stress. Also, these women should see their doctor 2 to 3 times a week. However, most women with mild preeclampsia are hospitalized, at least at first. There, they are kept in bed and monitored closely until the fetus is mature enough to be delivered safely. Drugs to lower blood pressure (antihypertensives) may be needed (see Drugs Used to Treat Heart and Blood Vessel Disorders). If blood pressure and other problems can be controlled, women may be able to go home, but they must see their doctor every 2 to 3 days.
If preeclampsia develops near the due date, labor is usually induced and the baby is delivered. Magnesium sulfate is given during labor to prevent seizures.
Severe preeclampsia and eclampsia:
As soon as severe preeclampsia or eclampsia is diagnosed, women are given magnesium sulfate intravenously to prevent or stop seizures. If women have seizures after being given magnesium sulfate, an anticonvulsant (diazepam or lorazepam) is given intravenously.
The baby may be delivered by cesarean, which is the quickest way, unless the cervix is already opened (dilated) enough for a prompt vaginal delivery. A prompt delivery reduces the risk of complications for the woman and fetus. If blood pressure is high, drugs to lower blood pressure, such as hydralazine or labetalol, may be given intravenously before delivery is attempted. The HELLP syndrome is usually treated the same way.
After delivery, women who have had preeclampsia or eclampsia are given magnesium sulfate for 24 hours and closely monitored for 2 to 4 days because they are at increased risk of seizures. As their condition gradually improves, they are encouraged to increase their activities. They may remain in the hospital for a few days, depending on the severity of the preeclampsia and its complications.
After returning home, these women may need to take drugs to lower blood pressure. Typically, they have a checkup at least every 1 to 2 weeks for the first few months after delivery. Their blood pressure may remain high for 6 to 8 weeks. If it remains high longer, the cause may be unrelated to preeclampsia.
Last full review/revision August 2013 by Antonette T. Dulay, MD