UW News

January 24, 2002

Preeclampsia: Frequent blood-pressure checks are important to find early signs of potentially dangerous condition

Pam Sowers
HS News & Community Relations

Soon-to-be mothers hope for an uneventful pregnancy. However, about one out of every 20 first-time moms develops high blood pressure and the condition preeclampsia.

Unfortunately, the only cure is delivering the baby. The hypertension will almost certainly improve after the baby is born. But nobody wants the baby to be born too early. So health care professionals carefully monitor and treat the high blood pressure to allow the pregnancy to progress as long as possible, says Dr. Darcy Carr, acting assistant professor of obstetrics and gynecology at the University of Washington.

“A frightening thing about this illness is that it can be a silent disease in a lot of people. Good prenatal care will allow a health care professional to follow trends in your blood pressure,” Carr says.

Preeclampsia is diagnosed by two features: high blood pressure and protein in the urine. The systolic pressure must be 140 or greater, or diastolic must be 90 or greater, over a period of time. To determine whether there is excess protein, a health care provider will evaluate either random urine samples or a 24-hour collection. If a woman has high blood pressure but protein levels are normal, the condition is called gestational hypertension. Gestational hypertension may progress to preeclampsia and should be watched closely.

A woman’s health care provider screens for preeclampsia because it can become serious. Preeclampsia may result in eclampsia — seizures — or kidney failure and liver damage. Eclampsia can, in rare cases, be fatal to both mother and child.

The first step in dealing with preeclampsia is to try to prevent it in the first place. Women who are already in a group at risk for getting preeclampsia are wise to seek advice from a health care provider before they get pregnant. These high-risk groups include women who already have chronic high blood pressure, diabetes, lupus or kidney disease. For some of these women, the risk can be significant, depending on the state of their condition and how well it is controlled.

“If you have one of those conditions, and are hoping to get pregnant, it’s a good idea to talk with your health care provider and optimize your blood pressure,” Carr says.

Sometimes, preeclampsia will develop in between blood pressure checks, and go unnoticed. It has other signs. This risk is one reason that doctors encourage women to let them know if they develop headaches, swelling or nausea in the latter third of the pregnancy. Another warning sign is abdominal pain.

If a woman develops preeclampsia, she may be asked to stay in the hospital while doctors monitor the health of both baby and mother. That’s because the medical staff will want to keep a close eye on their condition. There is a balancing act involved. On the one hand, they may try to offer medication to lower the woman’s blood pressure and keep the baby in the nurturing environment of the womb as long as possible. On the other hand, they do not want the mother’s or baby’s condition to worsen as the pregnancy is allowed to continue. It may be necessary to deliver the baby early for the protection of both mother and child.

A woman who has preeclampsia once may get it again. The risk is as high as 75 percent for women who developed severe preeclampsia at 30 weeks or sooner in their first pregnancy. The risk reduces to 40 percent for women who developed preeclampsia later in the pregnancy, and declines further for women who had only mild preeclampsia (under 160/110).

Meanwhile, researchers around the world are looking into what may be going on within a woman’s body and the placenta to cause preeclampsia. Carr’s own research involves examining insulin resistance (a risk factor for diabetes, heart disease and high blood pressure) in a history of preeclampsia.

“There may be some underlying condition that predisposes certain women to develop preeclampsia,” Carr says. “The goal is to find better ways to identify those women at risk, and prevent preeclampsia.”

Women in the Puget Sound area who delivered a baby less than 24 months ago may be able to participate in the study and receive free health testing. For an information packet, please call 206-221-643.