Vaginal delivery is associated with lower levels of thiol groups, vitamin C and ferric reducing ability in colostrum compared with caesarean section

Abstract

This study aimed to investigate the effects of delivery type (normal or caesarean) on the antioxidant and oxidative capacity of colostrum collected shortly after delivery. A total of 61 parturients were included in the study and divided into two groups: those who underwent vaginal delivery (n = 36) and those who underwent elective caesarean section (n = 25). Colostrum samples were collected by manual milking up to 48 h post parturition and analysed for thiol groups (–SH), vitamin C, ferric reducing ability (FRAP), nitrate/nitrite oxides (NO_x), and advanced oxidation protein products (AOPP). Colostrum levels of –SH (p = 0.0042), vitamin C (p = 0.0455), and FRAP (p = 0.0374) were significantly lower in the vaginal delivery group. The results suggest that vaginal delivery, compared to caesarean section, is associated with lower levels of antioxidants in colostrum and the mode of delivery plays an important role in the composition of antioxidants in maternal colostrum that help protect newborns from oxidative damage.

IMPACT STATEMENT

• What is already known on this subject? Colostrum is the first biological fluid produced by the mother after delivery and is responsible for a child’s growth, cognitive development and health. It is known that childbirth can cause oxidative imbalance, and its effects have already been evaluated in maternal and foetal blood, however, there are few studies evaluating the effects of childbirth on colostrum composition.

• What do the results of this study add? Previously, a study showed that caesarean section caused greater oxidation of colostrum compared to vaginal delivery. Thus, we sought to evaluate other markers (thiol groups, vitamin C, ferric reducing ability, nitrate/nitrite oxides, and advanced oxidation protein products), in a short period of time after delivery, in order to elucidate this still little discussed issue. Unlike the previous one, our study suggests that vaginal delivery, compared to caesarean section, is associated with lower levels of antioxidants in colostrum, which may make it difficult to protect newborns from oxidative damage.

• What are the implications of these findings for clinical practice and/or further research? Our study suggests that normal delivery can influence the antioxidant composition of maternal colostrum, and it is debateable for future clinical practice to improve eating habits during pregnancy and lactation, in order to strengthen the antioxidant capacity of colostrum and reduce oxidative damage to newborns.

Keywords:

• Antioxidant
• childbirth
• colostrum
• delivery
• oxidative damage
• FRAP

Acknowledgments

The authors would like to thank all the participants in this research who voluntarily agreed to participate.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study was supported by the Brazilian Federal Agency for Support and Evaluation of Graduate Education (CAPES).