What is the main risk factor for necrotising enterocolitis?

The main risk factor for necrotising enterocolitis (NEC) is prematurity. NEC primarily affects preterm infants, particularly those born before 28 weeks of gestation. The immature gastrointestinal tract in these premature infants is not fully developed, making it more susceptible to injury and infection, which can lead to the inflammatory condition known as NEC.

In preterm infants, the risk is compounded by factors such as delayed feeding, low birth weight, and the use of formula feeding rather than breast milk, which is known to provide protective factors. Although low birth weight is associated with NEC, it is closely tied to prematurity since most low birth weight infants are indeed born prematurely.

Other factors like high maternal age and intrauterine infections have less direct associations with the incidence of NEC compared to prematurity. While these factors may contribute to overall pregnancy complications, they are not as strongly linked to the specific risk of developing NEC after birth.