The purpose of this study is to evaluate the impact of the enteral nutrition type (untreated breast milk, or breast milk processed by the breast-milk bank) on the longitudinal evolution of the total content and plasma profile of essential fatty acids (EFA) in a population of premature infants.

Inclusion Criteria:

• Parent's written informed consent
• Gestational age less than 33 weeks of amenorrhea
• Hospitalisation in an NICU at the time of inclusion
• Intended enteral nutrition with breast milk

Exclusion Criteria:

• Persons not covered by the French social security system
• Major congenital malformation
• Participation in other biomedical study protocols
• Babies that are likely to be transferred to another hospital during the study period

for both groups, the gestational age at birth must be less than 33 weeks gestation and at the time of inclusion the child must be hospitalized in neonatal resuscitation