What defines a newborn as premature?

A newborn is defined as premature when it is born before 37 weeks of gestation. This definition is based on the understanding that normal full-term pregnancies typically range from 37 to 42 weeks. Infants born before 37 weeks, known as preterm infants, are at higher risk for various health complications due to their underdeveloped organs and systems.

Gestational age is a critical factor in assessing birth outcomes, as maturity levels of vital organs like the lungs, heart, and brain increase significantly throughout a full-term pregnancy. Premature infants may face challenges such as breathing difficulties, feeding problems, and a heightened risk of infections. The timing of birth in relation to gestational weeks is the most clinically relevant indicator of prematurity rather than factors such as weight, maternal drug use, or the presence of meconium.

These other factors may impact the health of the newborn but do not serve as defining criteria for prematurity. Weight, for example, can vary widely among babies born at the same gestational age, and while substance exposure during pregnancy is important, it does not influence the classification of whether a baby is premature.