Despite considerable obstetric and neonatal advances in the care of very low birth weight (VLBW) neonates, bronchopulmonary dysplasia (BPD) continues to occur among 20 to 40% of surviving infants, and new ways for combatting this disease must be found. BPD appears to result from arrested lung development, but its etiology has not yet been fully established. Besides the role of the exposure of the immature lung to injurious factors in the development of BPD, a genetic susceptibility for BPD in preterm infants was recently evidenced. Taking advantage of new genomic technologies, the objective of the investigators' project is to identify predisposing human genetic variants through:

1. a genome-wide association (GWA) study in VLBW neonates,
2. a candidate-gene association study, including selection of single nucleotide polymorphisms (SNPs) found in (a) and
3. functional studies of any SNP found to be convincingly associated with BPD in (a) and (b).

Inclusion Criteria:

• Gestational age < 28 weeks
• Inborn birth
• Prophylactic administration of surfactant in the delivery room
• Written informed consent obtained from parents

Exclusion Criteria:

• Gestational age of 28 weeks or more
• Outborn birth
• No prophylactic administration of surfactant in the delivery room
• Congenital malformation
• Absence of written informed consent obtained from parents

Premature neonates