Infant mortality refers to the death of an infant between 1 day and 1 year of age. (Deaths before age 28 days can also be classified as neonatal mortality.) There are many causes of infant mortality, ranging from infections to accidents.
NICHD supports research on many causes of and conditions that can lead to infant death, including Sudden Infant Death Syndrome (SIDS) and other sudden, unexpected infant deaths, birth defects, and preterm birth. The Institute also studies ways to prevent or reduce the risk of these causes and conditions to reduce infant mortality rates and improve infant health outcomes.