The document discusses infant mortality rate (IMR), which is the number of infant deaths per 1000 live births. It notes that IMR has significantly declined in modern times due to improved healthcare. IMR correlates with a country's level of development and health. While IMR has declined worldwide between 1960 and 2001, rates remain much higher in less developed countries compared to more developed countries. Common causes of infant mortality include low birth weight, respiratory issues, SIDS, and lack of essential needs. Efforts to reduce IMR focus on education, prenatal care, and maternal and child health services.