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How fever in early pregnancy might cause heart, facial birth defects

Tuesday, October 10, 2017
By Samiha Khanna
Eric Benner, MD, PhD

DURHAM, N.C. -- Researchers have known for decades that fevers in the first trimester of pregnancy increase risk for some heart defects and facial deformities such as cleft lip or palate. Exactly how this happens is unclear. Scientists have debated whether a virus or other infection source causes the defects, or if fever alone is the underlying problem.

Duke researchers now have evidence to suggest the fever itself, not its root source, could interfere with the development of the heart and jaw during the first three to eight weeks of pregnancy. Their findings, demonstrated in animal embryos, will be published Oct. 10 in the journal Science Signaling. The results provide new leads as scientists continue investigating heart defects, which affect 1 percent of live births in the U.S., and cleft lip or palate, affecting about 4,000 infants per year. 

The animal models suggest a portion of congenital birth defects in humans might be prevented if fevers are treated through means including the judicious use of acetaminophen during the first trimester, said senior author Eric Benner, M.D., Ph.D., a neonatologist and assistant professor of pediatrics at Duke.

“My hope is that right now, as women are planning to become pregnant and their doctors advise them to start taking prenatal vitamins and folic acid, their doctor also informs them if they get a fever, they should not hesitate to call and consider taking a fever reducer, specifically acetaminophen (Tylenol), which has been studied extensively and determined to be safe during the first trimester,” Benner said. “While doctors advise most women to avoid any drug during pregnancy, there may be benefits to taking acetaminophen to reduce fever. Women should discuss all risks and benefits with their doctors.”

Read more on DukeHealth.org