Neonatal period is the first 4 weeks of life of a newborn. Newborns who are born too soon or too small, or who become sick, are at the greatest risk of death and disability in the first 28 days. According to the study - Survive and thrive: transforming care for every small and sick newborn. In 2017, an estimated 2.5 million newborns died during the first 28 days of life.