Physiopathologie de la rétinopathie du prématuré

An Evaluation of Oxidative Status in Serum and Breast Milk of Mothers Giving Birth Prematurely and at Full-Term

Background:

Burning fat and carbohydrates to provide energy in biological systems causes the formation of free oxygen species.

Objectives:

This study aimed to evaluate the oxidative status of serum and breast milk of mothers giving birth prematurely and at full-term.

Materials and Methods:

The study comprised 50 mothers who gave birth at full-term at more than 38 weeks and 43 mothers who gave birth pre-term at below 32 weeks. On the postnatal 5th day, samples of the mother’s milk and serum were taken and stored at -80°C until the study day. On the study day, the total oxidant and total antioxidant levels were measured using the Erel method and the oxidative stress index (OSI) was calculated.

Results:

While the total oxidant level and total antioxidant level values of the milk of the premature birth mothers were found to be significantly high compared to those of the full-term birth mothers (P = 0.001), no statistically significant difference was found in the oxidative stress index values (P > 0.05). No statistically significant difference was found in the total oxidant level and oxidative stress index values of the serum of the premature birth mothers compared to those of the full-term birth mothers, while the total antioxidant level was found to be significantly low (P = 0.04).

Conclusions:

The oxidants and antioxidants in the milk of mothers giving birth prematurely were found to be significantly higher than those of full-term birth mothers. This can be evaluated as the milk of the premature birth mothers providing increased antioxidant defense to protect the infant.

Evidence of oxidative stress in relation to feeding type during early life in premature infants

Morbidity in the premature (PT) infant may reflect difficult adaptation to oxygen. We hypothesized that feeding including formula feeding (F) and feeding mother's milk (HM) with added fortifier would affect redox status. Therefore, 65 PT infants (birth weight: 1146 ± 261 g; GA: 29 ± 2.5 wk; mean ± SD) were followed biweekly, once oral feeds were introduced. Feeding groups: F (>75% total feeds) and HM (>75% total feeds) were further subdivided according to human milk fortifier (HMF) content of 0-19, 20-49, and ≥ 50%. Oxidative stress was quantified by F2-isoprostanes (F2-IsoPs) in urine, protein carbonyls, and oxygen radical absorbance capacity (ORAC) in plasma. F2-IsoPs (ng/mg creatinine): 0-2 wk, 125 ± 63; 3-4 wk, 191 ± 171; 5-6 wk, 172 ± 83; 7-8 wk, 211 ± 149; 9-10 wk, 222 ± 121; and >10 wk, 183 ± 67. Protein carbonyls from highest [2.41 ± 0.75 (n = 9)] and lowest [2.25 ± 0.89 (n = 12) pmol/μg protein] isoprostane groups did not differ. ORAC: baseline, 6778 ± 1093; discharge, 6639 ± 735 [full term 4 and 12 M, 9010 ± 600 mg (n = 12) TE]. Highest isoprostane values occurred in infants with >50% of their mother's milk fortified. Further research on HMF is warranted.