Definition of terms used to describe patient age information in the ACR Appropriateness Criteria® topics.
Neonate – Birth to 28 days old1.
Infant – Birth to one year old2.
Child – Younger than 18 years old3.
Adolescent – A transitional stage of physical development occurring between puberty and adulthood4
Adult –18 years old or greater.
Pregnancy age - Menarche to menopause (generally in the range of 10-60 years old).
1Merriam-Webster Dictionary. http://www.merriam-webster.com/dictionary/neonate. Accessed 21 March 2011.
2World Population Prospects: The 2019 Revision of World Population Prospects. Available at: https://population.un.org/wpp/. Accessed October 20, 2021.
3Convention on the Rights of the Child. UNICEF publications. Available at: https://www.unicef.org/child-rights-convention. Accessed 21 March 2011.4Christie D, Viner R. Adolescent development. BMJ 2005;330:301-4.