News Release

Fetal heart diagnosis doesn't always predict survival

In utero diagnosis increases treatment ability, but certain risks can factor into survival

Peer-Reviewed Publication

Michigan Medicine - University of Michigan

Chicago –– In the past decade, an increase in prenatal, or in utero, diagnoses of fetal heart conditions has allowed for early diagnosis, planning and counseling for families with infants that require surgical correction shortly after birth, in hopes of improving survival for this high-risk group.

However, new research from University of Michigan pediatric cardiologists who studied the survival rate of fetuses diagnosed with Hypoplastic Left Heart Syndrome (HLHS), a condition where the left ventricle of the heart is too small to help pump blood through the body, found that in utero diagnosis does not always help a baby's survival.

The study revealed that even with a prenatal diagnosis of HLHS, infants with one or more risk factors that are often not detectable before birth, such as low birth weight, had a significantly less chance for survival. But the researchers note that in utero diagnosis has meant that many more pregnant women referred to specialty care centers for treatment before risk factors can be identified, which results in a higher risk group of patients.

Those findings, from the U-M Congenital Heart Center's Prenatal Cardiology Clinic at U-M C.S. Mott Children's Hospital, will be presented this week at the 52nd annual Scientific Session of the American College of Cardiology in Chicago.

With nearly 600 patients each year, the U-M Prenatal Cardiology Clinic is one of a few clinics in the country to care for such a large number of high-risk patients –making it the ideal site to test the correlation between in utero diagnosis and survival rate of babies born with HLHS, according to co-investigator Cyrus Samai, M.D., a pediatric cardiology fellow in the U-M Department of Pediatric and Communicable Diseases.

About 50 percent of babies with HLHS at U-M are now diagnosed in utero due to improved technology and increased obstetrician awareness.

Although only 5 percent to 7 percent of children with a congenital heart disease have HLHS, the condition is responsible for 25 percent of all cardiac deaths in the first week after birth if either surgery or heart transplantation is not performed. The surgical process is palliative, and involves three phases, typically done during the first few years of a child's life.

However, even with corrective procedures available, several factors can decrease a baby born with HLHS chances for survival, says Carlen A. Gomez, M.D., the study's lead investigator, and director of the U-M Prenatal Cardiology Clinic.

"There are always unknowns until the baby is born," explains Gomez. "Certain factors can't be detected in utero, like if the baby will be born prematurely and those risk factors are what play a huge part in a child's survival."

The study closely examined the influence those potential risks had on the survival rate of 76 fetuses diagnosed in utero with HLHS at the U-M Prenatal Cardiology Clinic from June 1998 through December 2001.

By assessing the outcome of the patients, the researchers were able to identify four prominent risk factors associated with a decrease in survival rates: low birth weight/prematurity, obstructed pulmonary venous return, additional cardiovascular defects, and non-cardiovascular anomalies.

Of the fetuses in the study, 38, or 50 percent, had at least one risk factor. But only 16 of those 38 fetuses were identified as high-risk prenatally. More than half of the fetuses with one risk factor died, while 67 percent of those with two or more risk factors did not survive.

However, patients with no risk factors who went on to have surgery had an 80 percent survival rate.

"The extent to which risk factors do affect the survival of fetuses diagnosed with HLHS is significant," says Gomez. "For that reason, it's important that prenatal counseling of parents addresses the potential risks that we may not be able to detect before a child's birth."

Prenatal counseling is one of unique features of the U-M Prenatal Cardiology Clinic. The families of children diagnosed in utero at the clinic have the opportunity to meet with surgeons and cardiologists before the birth of their child, which helps them prepare for future examinations, surgery, or heart catheterization.

Social workers are also on staff to assist families with many issues related to having a child with a heart problem, such as lodging, meal assistance, insurance issues, and state or area resources. Child Life specialists and chaplains are available for hospitalized patients as well.

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To learn more about the U-M Congenital Heart Center and its Prenatal Cardiology Clinic, visit www-umchc.pdc.med.umich.edu/index.html.

In addition to Gomez and Samai, the study team from the U-M Department of Pediatrics and Communicable Diseases includes Mark W. Russell, M.D.; David A. Parra, M.D.; and Achiau Ludomirsky, M.D.

Written by Krista Hopson

Contact:
Krista Hopson, khopson@umich.edu
Kara Gavin, kegavin@umich.edu
734-764-2220


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