How fever in early pregnancy can cause birth defects

Story highlights

  • A fever early during pregnancy is known to cause some heart defects and a cleft lip or palate
  • Researchers demonstrated it is the fever, and not underlying infection, that causes birth defects

(CNN)Running a high fever during early pregnancy is known to be dangerous.

A first-trimester fever can increase a baby's risk of developing a congenital heart defect and certain facial deformities, such as cleft lip or cleft palate.