Heart Failure Can Kill Embryos
But ultrasound can help predict miscarriage, research says
TUESDAY, Dec. 2, 2003 (HealthDayNews) -- Congestive heart failure, a condition traditionally associated with the elderly, may also affect embryos and lead to miscarriage.
That's the theory of an Illinois radiologist who is to present his findings Dec. 2 at the Radiological Society of North America's annual meeting in Chicago.
In practice, using Doppler ultrasound early in pregnancy can identify embryotic congestive heart failure and the risk of miscarriage, speculates Dr. Jason Birnholz.
Approximately 20 percent of recognized pregnancies end in miscarriage, according to the National Center for Health Statistics.
"We've identified a new kind of mechanism of fetal loss," Birnholz says. "There is a form of congestive heart failure that accounts for a lot of fetal loss. CHF is something you tend to think about in old folks with CHD (coronary heart disease). It has not been identified as such in embryos."
But another radiologist cautions that more study is needed on the topic.
Birnholz performed Doppler ultrasound imaging to evaluate embryonic heart function early in the first trimester. A probe was inserted into the vagina to perform the test. The ultrasound measured the speed of red blood cells passing through vessels to determine the pressure dynamics within the embryo's heart.
Obstetrical ultrasound is performed for a number of reasons, including to establish the presence of a living embryo or fetus, to estimate fetal age, to diagnose congenital abnormalities, and to determine if there are multiple pregnancies.
Birnholz evaluated 1,800 cases in all, including 1,200 women whose ultrasounds showed no abnormalities. In another 125 women, 95 percent of the ultrasounds were abnormal and the women later miscarried. In another 475 cases, the ultrasound findings confirmed that the baby had died due to congestive heart failure -- even though miscarriage had not yet occurred, he says.
"From 20 to 40 percent of miscarriages are due to chromosome abnormalities and 60 percent are unknown," Birnholz says. CHF may explain many of those, he adds.
"It may be that the heart is forming normally, but it doesn't get the oxygen and other nutrients it needs," Birnholz says.
When Doppler ultrasound confirms normal embryonic heart function at six weeks, the chances the pregnancy will continue are high, about 95 percent, Birnholz says. But more than 99 percent of pregnancies that show up abnormal on the Doppler end in miscarriage, he says.
The finding, Birnholz says, may lead to the discovery of treatments for pregnant women to prevent heart problems in fetuses.
Dr. Thomas Grant, a radiologist and associate professor of radiology at the Feinberg School of Medicine at Northwestern University in Chicago, says Birnholz's "study findings are very interesting."
"But further research is needed," he adds. "It may turn out to be a valid observation. This has interesting theoretical implications for future treatment and research on the embryo."