Counting Chickens Before They Hatch? Researchers Are Counting on Chicken Embryos to Address Congenital Heart Defects in Humans

Don’t count your chickens before they hatch, the saying goes. In this case, researchers are counting on chicken embryos to help them understand and address the most common birth defect among humans — congenital heart defects.

About 10% of humans are born with a congenital heart defect (CHD), which occurs when the heart does not form properly in development. The most common CHD is a hole in the heart, or persistent truncus arteriosus, and is not detectable until after the baby is born.

A team of researchers at the California Institute of Technology are studying chicken embryos to discover the genetic pathways that certain stem cells use to properly form heart tissue, according to, which wrote about the study that appeared in the journal Developmental Cell. The Caltech researchers believe that other stem cells could be reprogrammed with the same genetic instructions to prompt them to make heart tissue.

Understanding these genetic processes could one day enable doctors to detect persistent truncus arteriosus before birth and possibly correct the defect without surgery while the baby is still in the womb, the article said.

“We are very excited about these results because they are the first to show that a small number of genes enable neural crest cells to form a barrier that separates blood flowing to and from the heart and the lungs,” said Marianne Bronner, Albert Billings Ruddock professor of biology. “Our hope is that this will lead to a better understanding of birth defects that cause heart abnormalities.”

Chicken embryos were used because they have similar genes and developmental processes as humans in the early embryonic stage, the article said.

What Causes a Congenital Heart Defect (CHD)?

In a healthy human baby, deoxygenated blood gets pumped through a one-way blood vessel to the lungs, where it becomes oxygenated and is pumped back to the heart through a separate blood vessel. But in a baby with persistent truncus arteriosus, the hole causes oxygenated and deoxygenated blood to mix. Too little oxygen gets to the body, and the heart must work harder. Surgery is necessary to repair the hole.

CHDs account for about a third of all birth defects. They are a leading cause of spontaneous abortion, stillbirth, and neonatal and infant mortality, according to a research paper “Environmental Contaminants and Congenital Heart Defects: A Re-Evaluation of the Evidence,” which was published in the International Journal of Environmental Research and Public Health.

About 30% of infants who die at birth are found to have a CHD. About 30% of all CHDs can be attributed to genetic disorders or other known causes, while the remaining 70% is unknown. The paper says that environmental contaminants that have been classified as endocrine disruptors also appear to play a role. Recent studies of prenatal exposure by a mother or father to agricultural pesticides, solvents, metals and landfill sites showed associations with certain CHDs, the paper said.

How We Help Birth Defects Victims 

The attorneys of our birth defects victims alliance understand the pain that families face when coping with life-altering birth defects—and the frustration of knowing they could have been prevented. Our team has over 30 years of combined experience in birth defects litigation in cases involving toxic exposure. We have the resources and experience to fight on behalf of our clients against corporations who put them in danger. Call us to see how we can help you and your family receive justice for birth defects.