The aim of the study is to determine mechanisms leading to glutathione deficiency in low birth weight newborn babies. Compared to full term neonates, depletion in this population may be due to a decreased synthesis rate or to an enhanced utilization or a combination of both mechanisms.The protocol is constituted of two steps. The objective of the first step is to quantify the blood concentration of glutathione in the artery and the vein of umbilical cord in full term newborn babies. Objectives of the second step are to determine if the glutathione synthesis rate, measured in vitro, is lower in erythrocytes collected from umbilical cord blood of low weight newborn babies compared to full term newborn babies. In this case, the next objective will be to determine if the adjunction of an excess of cysteine in vitro can restore the glutathione synthesis rate in these cells.

Inclusion Criteria (first step):

• Full term newborn babies
• Gestational age > 37 weeks of amenorrhea and weight of birth > tenth percentile
• Eutocic delivery

Inclusion Criteria (second step):

• Low birth weight newborn babies (gestational age < 32 weeks of amenorrhea and/or weight of birth < 1500 g and/or weight of birth < third percentile for their gestational age)
• Full term newborn babies (gestational age > 37 weeks of amenorrhea and weight of birth > tenth percentile)

Exclusion criteria (first and second step):

• Mother diastolic blood pressure > 90 mmHg during pregnancy,
• pH < 7.2 at umbilical cord and/or difference in pH < 0,02 between arterial pH and venous pH
• Dystocic delivery
• Bacterial or viral maternofoetal infection
• Foetal malformation
• Foetal disease
• Taking N-acetyl-cystein or vitamines and antioxidant minerals by the mother for the last 24 hours