New Scale Pinpoints Heart Risk in Pregnancy
Canadian development could direct women at high risk to the right place
MONDAY, July 30, 2001 (HealthDayNews) -- In a collaborative nationwide study, Canadian cardiologists and obstetricians have developed a four-point scale to assess pregnancy risks for women with heart disease.
Overall, the development is good news for women with heart problems, says Dr. Samuel C. Siu, associate professor of medicine at the University of Toronto, a leader of the study. "Most of these women go through pregnancy without complications," Siu says. The four-point scale that came out of the study will help direct women at high risk to specialized treatment centers, he says.
Such heart problems are not common, affecting one in every 100 or 200 pregnant women, says a report in the July 31 issue of Circulation: Journal of the American Heart Association. So studies have tended to be rare, and most of them in the medical literature were done decades ago and usually aimed at one specific condition or another, Siu says.
"Medicine has changed a lot over the last 10 to 20 years, and many studies do not reflect the availability of modern cardiac obstetric care," Siu says. The new study is one of the largest ever done, he says. It also is one of a very few to look at a broad range of heart conditions.
Cardiologists and obstetricians in 13 Canadian medical centers studied the outcomes, like congenital disorders, of 599 pregnancies in women with heart conditions. In 13 percent of the pregnancies, there were serious complications, including excess fluid in the lungs and abnormal heartbeats. There were also three deaths.
Four factors were good predictors of complications, the researchers say. One is a prior cardiac event, such as a mini-stroke or heartbeat irregularity. The second is cyanosis, a reduction in the body's oxygen supply. The third is narrowing of the heart valves, and the fourth is decreased pumping ability of the heart. Each is given one point in the scale.
Only 5 percent of the women with none of these risk factors had a cardiac event. The risk was 27 percent for one risk factor and 75 percent for two or more.
The big advantage of the new study is that it provides an overall picture in a field that has been fragmented, Siu says. Now there is one scale that can be used to assess risk for all heart problems, he says, adding, "It will complement what we call the disease-risk factors we know about."
Dr. Iffath Hoskins, chairwoman of the department of obstetrics and gynecology at New York University Downtown Hospital, has the same reaction. "Having practiced in this field for 26 years, I agree that the information available prior to a study like this has been spotty and patchy," she says. "This information can save all of us clinicians a fair amount of time because it will help us better understand these outcomes. Most of the information they have is not new, but the way they have put it together is very good."
Hoskins says the Canadian risk scale could eventually replace the New York Heart Association criteria, which is the risk-assessment method now used by obstetricians.
"For the first year or two, it will be a case of learning a new entity," she says. "We will be seeing what happens clinically if we convert from the New York Heart Association criteria. This is a very useful index score that could replace what we now have, hopefully, over time."
What To Do
The American Heart Association recommends that any woman with a heart condition should consult a physician before she intends to become pregnant.
For background information on heart conditions and pregnancy, go to the American Heart Association.
The Mother and Baby Web site in Britain has more information on looking ahead to a healthy child.