The New York Times News Service

Terry Coffey was 27 weeks pregnant when she was admitted to the hospital for observation because her blood pressure had shot up and her obstetrician worried that her life might be in danger.

The diagnosis was preeclampsia, a disorder that can arise in pregnancy; it is characterized mainly by the sudden onset of high blood pressure. Coffey, 40, a nurse who lives in Westchester County, N.Y., thought that her doctor was overreacting. Although she knew that preeclampsia could be dangerous, she felt fine.

But three days after her admission to the hospital, Coffey started feeling odd. Her reflexes became twitchy and hyperreactive. And blood tests showed that her kidneys were failing. The only way to save her life was to deliver the baby immediately, doctors said.

"It all happened so fast, I don't think I realized how much danger I was in," Coffey recalled. "You can have seizures, intracranial bleeding, kidney failure. I kept thinking about my son."

Preeclampsia, one of the most dangerous and perplexing complications of pregnancy, appears to be on the rise, experts say.

It has typically affected about 5 percent of pregnancies in the United States, but over the past decade, reports of it have increased by 40 percent, according to a report issued in April by the National Center for Health Statistics, a branch of the Centers for Disease Control and Prevention.

Some of the rise may reflect increased reporting because of greater awareness of the condition. But Dr. James Roberts, director of the Magee-Womens Research Institute and professor and vice chairman of the department of obstetrics, gynecology and reproductive sciences at University of Pittsburgh, said that he and other experts thought cases of preeclampsia had actually increased.

Older women have a greater risk of preeclampsia, as do women carrying more than one fetus. Preeclampsia, sometimes called toxemia, is usually detected when a woman's blood pressure rises sharply after the 20th week of pregnancy. In some cases, the woman's body also retains fluid, and her hands and face may swell. In severe cases, preeclampsia can be fatal to both mother and baby.

The rise in blood pressure is just a symptom. In a normal pregnancy, the developing fetus signals the mother's body to widen blood vessels, especially those feeding the placenta.

But in women suffering from preeclampsia, the opposite happens. Instead of dilating, blood vessels constrict. As a result, there is a drop in the blood supply to the woman's major organs and an increased tendency for the blood to clot.

"Deaths due to preeclampsia are very rare in the U.S., at eight to 10 per 100,000 births," said Dr. John Repke, president of the North American Society for the Study of Hypertension in Pregnancy and chairman of the department of obstetrics and gynecology at the University of Nebraska Medical Center in Omaha. "Still, it's the second-leading cause of maternal death in this country."

Scientists do not yet know what causes preeclampsia or how to prevent it. Dr. Laxmi Baxi, vice chairwoman of obstetrics and gynecology at the Columbia-Presbyterian Center, said, "I think what we can say at this point is that older women and those with pre-existing high blood pressure, diabetes, obesity or a multiple-gestation pregnancy are more likely to develop pre-eclampsia."

A study published in The New England Journal of Medicine in March pointed to the genetic makeup of the fetus, perhaps even a trait inherited from the father, as one of the factors that could predispose a pregnancy to preeclampsia. That theory is based on the finding that a woman's risk of preeclampsia rises if her husband's mother had the condition.

Another study published in March in The Journal of the American Medical Association showed that a defect in a woman's own blood vessels might predispose her to the condition. In that study, Dr. John C. Chambers and colleagues from the Imperial College School of Medicine in London scrutinized the arteries of more than 100 women who had experienced one or more pregnancies affected by preeclampsia and compared them with those of women who had had normal pregnancies.

The researchers squeezed the blood vessels by inflating blood pressure cuffs on the women's arms for several minutes. Then they released the pressure.

Normally the blood vessels would dilate to allow more blood to flow back to the lower arm. But women who had had preeclampsia showed significantly less dilation than women who had had normal pregnancies.

When the researchers treated the pre-eclamptic women with vitamin C, and repeated the experiment, the women's blood vessels behaved more normally. But the experiment does not mean that women at risk for preeclampsia should begin dosing themselves with vitamin C; more studies are needed, the researchers said.

Roberts said the women in the study were given hundreds of times as much vitamin C as the recommended daily dose.

"At this dosage, it's more of a drug than a vitamin, and we don't yet know if this is safe for the baby," Roberts said.

But he also said that if the findings held up, they might lead to a new treatment.

That would be good news for women like Coffey, who said she wondered whether she was ready to take the risk of having another baby. It took six months for her kidneys to return to normal. And though her 4-year-old son is fine now, he was born weighing less than two pounds and spent several months in intensive care.

"It changes the way you think about pregnancy," Coffey said. "You know things can happen, but until they happen to you, until you go through it day by day and see how things can change in a heartbeat, you don't really understand. It makes you really think twice."

Copyright 2001 The New York Times News Service. All rights reserved.