Study Sheds Light On Cause Of Preeclampsia 

Last Months of Pregnancy Could Include Problem Related to High Blood Pressure

Among the most serious of pregnancy complications is a condition known as preeclampsia, a blood pressure-related problem that can develop in the last trimester and threaten the life of both mother and baby.

Now a group of British physicians say they might have a way of predicting who is at risk for preeclampsia, long before symptoms occur.

In a new study appearing in the the medical journal The Lancet, physicians from Harris Birthright Centre, Kings College Hospital, London, say problems appear linked to a dysfunction in the cells that line blood vessels - called endothelial cells - and a natural chemical known as asymmetric dimethylarginine (ADMA).

"Maternal endothelial function is impaired in women who eventually develop preeclampsia, and it occurs before the development of the clinical syndrome," writes study author Kypros Nicolaides.

Predicting Preeclampsia

Women who are at risk for preeclampsia, he says, appear to have high concentrations of ADMA. That chemical seems to contribute to the dysfunction of the cells within blood vessel walls.

"The results of this study may help the development of more accurate tests for the prediction and more effective treatment of preeclampsia," says Dr. Nicolaides.

While experts say the study is well done and holds promise, according to obstetrician Dr. Steve Farber, president of the medical staff at Maimonides Medical Center in New York City, it is only one of many promising insights into the cause of preeclampsia.

"With each new study we find another piece of the puzzle, and we have a little better understanding of this complex problem and why it occurs," says Dr. Farber.

And while he says researchers have focused on the endothelial cells before, it remains to be seen just how significant ADMA is the big picture, he says.

Although Dr. Farber says finding this new information can lead to new hope in the future, he adds that right now it does little to change the clinical picture of preeclampsia since delivery still remains the only treatment option.

Preeclampsia is characterized by a swelling that can occur throughout the body, usually accompanied by a rapid rise in blood pressure. It normally begins late in the third trimester and affects 7 percent to 10 percent of all pregnant women, particularly older mothers or those carrying twins or triplets.

In some instances, preeclampsia can develop into the more severe condition known as eclampsia, causing a potentially fatal swelling in the brain.

Dr. Farber says women and their physicians are often forced to play a difficult waiting game, hoping to give the baby enough time to fully develop within the womb, but still delivering early enough to avoid eclampsia.

Clues Provide Hope

The new study involved two groups of 43 pregnant women who had a Doppler ultrasound examination of the uterus (a test that documents blood flow) in their second trimester, while blood tests checked levels of ADMA.

In the first group of 43, the women were shown to have normal uterine arteries and no elevations in ADMA. Subsequently, they all delivered normally with no complications.

In the second group of 43, the Doppler exam revealed impaired blood flow between the uterus and the developing baby. Of this group, 44 percent went on to have normal pregnancies and healthy births. In 33 percent of these women, however, babies developed intrauterine growth restriction, putting them at risk for low birth weight.

The remaining 23 percent developed preeclampsia. Because the Doppler exams revealed abnormal blood flow within the uterine arteries, as well as abnormal blood vessel dilation, researchers suggest arterial dysfunction as a factor in the development of preeclampsia.

More importantly, the women at risk for either preeclampsia or intrauterine growth restriction also had what researchers call a "striking elevation" in the concentration of ADMA in their blood. They say this substance may one day serve as a marker for women at risk.

Always consult your physician for more information.

What Is Preeclampsia?

Preeclampsia, also called toxemia, is a condition characterized by pregnancy-induced high blood pressure, protein in the urine, and swelling due to fluid retention.

Eclampsia is the more severe form of this condition, which can lead to seizures, coma, or death.

The cause of preeclampsia is unknown, but it is more common in first pregnancies. It affects about 7 percent to 10 percent of all pregnant women. Other risk factors for preeclampsia include the following:

Symptoms may include severe swelling of the hands and face, high blood pressure, headache, dizziness, irritability, decreased urine output, abdominal pain, and blurred vision.

Treatment will vary according to the severity of the condition and the stage of the pregnancy. Treatment may include hospitalization, bedrest, medication to lower the blood pressure, and close monitoring of both the fetus and the mother.

Online Resources

(Our Organization is not responsible for the content of Internet sites.)     

American College of Gastroenterology

American College of Obstetricians and Gynecologists

American Society for Reproductive Medicine

Centers for Disease Control and Prevention (CDC)

Colon Cancer Alliance

National Cancer Institute (NCI), part of NIH

National Institute of Child Health and Development (NICHD)

National Institutes of Health (NIH)

National Women's Health Information Center

June 2003

Study Sheds Light On Cause Of Preeclampsia

Predicting Preeclampsia

Clues Provide Hope

What Is Preeclampsia?

Study: High-Fiber Diet Helps Prevent Colon Cancer

What Are the Symptoms of Colorectal Cancer?

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Study: High-Fiber Diet Helps Prevent Colon Cancer 

In the latest evidence pointing to the benefits of eating fiber, researchers on both sides of the Atlantic report a high-fiber diet reduces the risk of colon cancer.

That conclusion, reported in two studies published in the medical journal The Lancet, reinforces earlier medical advice recommending high-fiber diets.

Other studies in recent years, however, have found high-fiber diets provided no protection against colon cancer, calling into question long-held beliefs.

In the European study, which the researchers called the largest ever on the relationship between diet and cancer, the scientists tracked more than one-half million people in 10 countries for an average of 4 and one-half years.

Those who averaged 35 grams of daily fiber intake had a 25 percent lower risk of colorectal cancer, primarily colon cancer, compared with those who averaged 15 grams of fiber a day, the study found.

"The most interesting thing is, it does actually confirm all the other studies prior to the most recent ones," which found no relationship between high-fiber diets and cancer, says Dr. Sheila A. Bingham, the lead author of the European study.

"Eat more plant foods because then you're eating more whole-grain cereal, more fruits and vegetables - that's the message coming through," adds Dr. Bingham, at the UK Medical Research Council's Dunn Human Nutrition Unit in Cambridge.

The US study focused on 37,600 people, about 3,600 of whom had non-malignant polyps - precursors to colon cancer. The researchers divided the participants into five groups according to their fiber consumption.

Those who ate the most fiber, an average of 36.4 grams a day, had a 27 percent lower risk of the polyps than those who ate the least fiber, averaging 12.6 grams a day, the study found.

To achieve those protective effects, the latest research suggests, Americans would have to consume much more fiber than they currently do. The US study shows Americans average about 16 grams of fiber a day.

"You really can see the risk [of colon cancer] is going down when the fiber is increasing; it's a very strong trend," says Dr. Ulrike Peters, the lead author of the US study. "This is a positive finding because it is consistent with health recommendations" for fiber intake, adds Peters, a researcher at the National Cancer Institute (NCI).

Both studies looked at fiber in foods only, drawing no conclusions about the potential protective value of fiber in dietary supplements.

Dr. Bingham suggests earlier research could have mistakenly concluded fiber had no preventive effect because of smaller amounts of fiber eaten and less variety in the amounts and types.

But Dr. M. Robert Cooper, the principal investigator of the 2000 Polyp Prevention Trial, says he stands by its findings that a high-fiber diet does not protect against colon cancer.

"It's not a major factor in preventing colon cancer," Dr. Cooper says of fiber. "We need to go on to something that's more significant than fiber," he adds, calling for more emphasis on screening for colon cancer.

Always consult your physician for more information.

What Are the Symptoms of Colorectal Cancer?

The following are the most common symptoms of colorectal cancer. However, each individualmay experience symptoms differently.

People who have any of the following symptoms should check with their physicians, especially if they are over 50 years old or have a personal or family history of the disease:

The symptoms of colorectal cancer may resemble other conditions, such as infections, hemorrhoids, and inflammatory bowel disease. It is also possible to have colon cancer and not have any symptoms.

Always consult your physician for a diagnosis.