Preeclampsia test could identify women at risk

A high-tech test to predict which pregnant women will develop preeclampsia before symptoms arise is being developed by researchers in Alberta.

Preeclampsia is marked by sudden spikes in blood pressure, swelling and rapid weight gain during pregnancy as well as high amounts of protein in the woman's urine. It is one of the leading causes of maternal deaths worldwide, affecting four million women every year.

'Sometimes, they take their babies with them, but sometimes, their babies survive.' — Dr. Louise Kenny

Currently, the only treatment is to deliver the baby, often weeks or months prematurely. Taking ASA and bed rest are the best recommendation doctors can make.

Now, researchers have found 14 telltale metabolites — sugars, fats or amino acids — in blood that could point to preeclampsia risk early in pregnancy, according to a study published in the October issue of the journal Hypertension.

"The way we imagine the test working is that in early pregnancy a woman will have the blood test, and that will depict if she is at risk or not," Dr. Louise Kenny of the University of Alberta in Edmonton, one of the study's principal investigators, said in an interview.

The study involved about 7,000 women participating in an international study of first-time pregnancies.

The goal is to bring the rates of maternal death in undeveloped countries down to the rates in developed countries, the researchers said.

The study had two parts. First, the researchers took samples at 15 weeks gestation from 60 women who went on to develop preeclampsia, as well as 60 controls of the same age, ethnicity and body mass index. The women were mostly New Zealanders about 30 years old on average.

The researchers then tested their method on another group of women in Australia.

Investigators identified 14 metabolites that had a detection rate of 90 per cent and a false positive rate of around 21 per cent to 24 per cent — more accurate than pregnancy screening for Down syndrome, the researchers said.

Widowed fathers

Eleni Tsigas, executive director of the Preeclampsia Foundation, said a high calibre test to identify those at high risk for preeclampsia could help determine which women should seek obstetric care from specialists and be monitored more vigilantly.

It's heart wrenching for obstetricians who see women and their babies affected by the condition, said Kenny.

"Sometimes, they take their babies with them, but sometimes, their babies survive," Kenny said in a news release. "To see the legacy of a widowed father with an infant who may or may not be seriously ill himself is an experience that you really only want to do once."

Those experiences motivated Kenny during the 10 years of research, she said.

Screening advantages

Early diagnosis might not have changed anything for preeclampsia survivor Cheryl Walker.

Walker's son Gabriel was born three months premature after her blood pressure spiked. Gabriel died half an hour after being born. Early diagnosis might not have changed anything, but the Edmonton resident said at least it would have prepared her.

"It will stop that terrible whiplash that I had where I went from perfectly normal, perfectly average pregnancy to: 'You are going to die,' " Walker said.

The sooner preeclampsia is diagnosed, the better, said Dr. Peter Von Dadelszen of BC Women's Hospital in Vancouver, who works with high-risk pregnancies and was not involved in the study.

"So the ability to identify those women before they become symptomatic through a screening test means that you can increase surveillance through laboratory tests and ultrasound scans," Von Dadelszen said.

The research team is working on a blood test that it hopes will be ready in three to five years. Medications are in development for preeclampsia, and the researchers say the test could help determine who should take the treatments in the future. 

Preeclampsia affects 2.6 per cent of pregnancies in Canada, according to Health Canada.

The study was funded by the New Enterprise Research Fund, Foundation for Research Science and Technology; Health Research Council; and Evelyn Bond Fund, Auckland District Health Board Charitable Trust (New Zealand); Premier’s Science and Research Fund, South Australian Government; and Ireland's Health Research Board.