Educational Content: This article is for informational purposes only and does not constitute medical advice. Always consult a healthcare provider for diagnosis and treatment.
Definition of Prematurity
Medically reviewed by Min Clinic Staff | Updated: January 2026
Prematurity: Historically, the definition of prematurity was 2500 grams (about 5 1/2 pounds) or less at birth. The current World Health Organization definition of prematurity is a baby born before 37 completed weeks of gestation, counting from the first day of the last menstrual period (LMP).