The aim of this study was to evaluate the possible relationship between polymorphisms: Il-1β 3953C>T, Il-6 −174G>C and −596G>A, TNFα −308G>A, and 86 bp variable number tandem repeat polymorphism of interleukin-1 receptor antagonist (Il-1RN VNTR 86 bp) and three polymorphisms that may participate in arteries tension regulation and in consequence in intestine blood flow impairment: eNOS (894G>T and −786T>C) and END-1 (5665G>T) and NEC in 100 infants born from singleton pregnancy, before 32 + 0 weeks of gestation, exposed to antenatal steroids therapy, and without congenital abnormalities. The gene discussed is IL1B; the disease is necrotizing enterocolitis.