Maternal Blood Test Identifies Congenital Heart Diseases in Fetus

Each year, around 1,000 children are born with a single ventricle heart defect (SVHD), a condition where one of the heart's lower chambers is underdeveloped, too small, or missing a valve. While survival is possible for children with SVHDs, their quality of life is significantly affected due to having only one functional ventricle. This serious congenital heart defect requires immediate treatment after birth. As the number of fetal therapies increases, the importance of early diagnosis becomes even more pronounced. Early detection of congenital heart diseases during pregnancy would not only provide physicians with additional time to plan treatment but also reduce the financial burden on families. It would enable them to consider earlier therapeutic options that could enhance survival rates and improve outcomes for newborns facing life-threatening heart conditions. Currently, the standard method for diagnosing congenital heart disease prenatally occurs at the five-month mark of pregnancy through ultrasound, at which point the disease is usually advanced enough to be visually identified. This method relies on imaging technology and equipment, leading to increased healthcare costs and heightened risks of healthcare inequity.

Researchers at Nationwide Children's Hospital (Columbus, OH, USA) have now discovered a potential biomarker that could detect the presence of SVHDs in a fetus through a maternal blood test. This test analyzes elevated levels of cell-free microRNAs (miRNAs) in the blood of mothers carrying a fetus with single ventricle heart disease. According to a research letter published in Circulation Research, these cell-free miRNAs could eventually serve as noninvasive biomarkers for earlier prenatal detection of single ventricle heart diseases.

In their study, the researchers utilized deep sequencing to identify elevated cell-free miRNAs in the maternal blood of pregnant participants carrying a fetus diagnosed with SVHD. They also employed induced pluripotent stem cells (iPSCs) to examine the functions of these miRNAs in the proliferation of human cardiomyocytes. The findings suggest that these cell-free miRNAs in maternal blood hold promise as noninvasive biomarkers for the prenatal detection of fetal SVHDs, pending additional animal studies and clinical validation.

“This technology is in an early phase; preclinical studies and additional clinical validation is needed, but we are encouraged by what this could mean for the evolution of detecting and managing single ventricle heart diseases in children,” said Mingtao Zhao, DVM, PhD, senior author of the study and associate professor in the Center for Cardiovascular Research at Nationwide Children’s. “This is a step toward further improved outcomes for newborns with congenital heart diseases.