Preeclampsia is high blood pressure that is accompanied by protein in the urine and that develops after the 20th week of pregnancy.
About 3 to 7% of pregnant women develop preeclampsia (toxemia of pregnancy). In this complication, an increase in blood pressure is accompanied by protein in the urine (proteinuria). Preeclampsia develops after the 20th week of pregnancy and usually before the end of the first week after delivery.
The cause of preeclampsia is unknown. But it is more common among women who
Preeclampsia may lead to premature detachment of the placenta from the uterus (placental abruption). 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.
Preeclampsia may cause fluids to accumulate (edema), resulting in swollen feet or hands. Women may gain excess weight. Tiny red dots (petechiae) may appear on the skin. Women may feel jittery. If severe, preeclampsia can damage organs, such as the brain, kidneys, lungs, or liver. Then women may have headaches, distorted vision, confusion, difficulty breathing, pain in the upper abdomen, vomiting, or other symptoms. A woman who has a new headache that does not resolve with acetaminophen or within 24 hours should call her doctor.
A variation of severe preeclampsia, called the HELLP syndrome, occurs in some women. It consists of the following:
In 1 of 200 women who have preeclampsia, blood pressure becomes high enough to cause seizures. This condition is called eclampsia. One fourth of the cases of eclampsia occur after delivery, usually within the first 4 days. If not treated promptly, eclampsia may be fatal.
Diagnosis and Treatment
Doctors diagnose preeclampsia when a woman has the following:
Doctors may do blood and urine tests to confirm the diagnosis and to check for organ damage.
If mild preeclampsia develops early in the pregnancy, bed rest at home may be sufficient, but such women should see their doctor frequently. If preeclampsia worsens, women are usually hospitalized. 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 Drug Use During Pregnancy). A few hours before delivery, magnesium sulfate may be given intravenously to reduce the risk of seizures. If preeclampsia develops near the due date, labor is usually induced and the baby is delivered.
If preeclampsia is severe, 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 closely monitored for 2 to 4 days because they are at increased risk of seizures. As their condition gradually improves, they are encouraged to walk. 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 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 December 2008 by Edmund F. Funai, MD