Necrotizing enterocolitis is the most common gastroenterological emergency in neonatology. Its mortality is high, ranging from 15 to 30%. Prematurity is the main risk factor for necrotizing enterocolitis, as well as the very low birth weight (<1500 g) associated with prematurity. Among the early neonatal complications of intrauterine growth restriction neonates, necrotizing enterocolitis is frequently reported in the literature. The situation of chronic hypoxia of these fetuses is at the origin of a vascular redistribution favoring the cerebral circulation to the detriment of the mesenteric vascularization, which could lead to the development of an necrotizing enterocolitis. However, data from the literature concerning this over-risk of necrotizing enterocolitis in the case of intrauterine growth restriction are discordant. The heterogeneity of the definitions used for the intrauterine growth restriction and diagnostic criteria for necrotizing enterocolitis from one study to another could explain these discrepancies. The investigator's hypothesis is that the risk of necrotizing enterocolitis is higher among newborns in intrauterine growth restriction compared to control children.

Inclusion Criteria:

• All birth between 24 + 0 weeks of amenorrhea and 36 + 6 weeks of amenorrhea
• with isolated intrauterine growth restriction at the maternity ward of the hospital Femme-Mère-Enfant
• from 1st of january 2011 to 31 december 2016.

Inclusion Criteria for control group:

• All birth between 24 + 0 weeks of amenorrhea and 36 + 6 weeks of amenorrhea
• without isolated intrauterine growth restriction at the maternity ward of the hospital Femme-Mère-Enfant
• from 1st of january 2011 to 31 december 2016.

Exclusion Criteria:

• Infants born out of the hospital and secondarily hospitalized in our department
• unaccompanied pregnancies
• multiple pregnancies
• children with malformations or genetic abnormalities,
• medical termination of pregnancy
• fetal deaths in utero

All birth between 24 + 0 weeks of amenorrhea and 36 + 6 weeks of amenorrhea with isolated intrauterine growth restriction at the maternity ward of the hospital Femme-Mère-Enfant from 1st of january 2011 to 31 december 2016.

To each of these children with intrauterine growth restriction is matched a control child: the child without intrauterine growth restriction of the same gestational age whose date of birth is consecutive to that of the case.