A Survey on Diagnosis and Prognosis of Prenatal Asphyxia based on Antioxidant Oxidant Balance: Evidence from a Systematic Review and Meta-Analysis.

Introduction: The mechanism of occurrence and complications of asphyxia change in the treatment process and the future prognosis of newborns. One of the discussed mechanisms is the disruption of oxidants to anti-oxidants balance. Therefore, the current study was conducted aiming to systematically review and conduct a meta-analysis on the diagnosis and prognosis of prenatal asphyxia based on oxidant-antioxidant balance.

Methods: A comprehensive electronic search was conducted using PubMed, Cochrane Library, Scopus, and Web of Science databases, up to February 2023 to identify relevant studies examining the association between Prooxidant anti-oxidant balance (PAB) and Malondialdehyde 1 levels with the risk of prenatal asphyxia. Only English studies were incorporated. The search terms used included Asphyxia, Diagnosis, Prognosis, Newborns, Prenatal, Oxidant antioxidant balance, and oxidative stress. A total of 13 studies were retrieved. Data regarding the standard mean difference (SMD) were collected, and a pooled SMD with 95%CI was calculated using a random-effect model to determine the strength of the relationship. Furthermore, the risk of publication bias was assessed through funnel plot and Egger's linear regression tests. Inclusion criteria was 1) The studies conducted on neonates, diagnosis and outcomes of prenatal asphyxia, oxidants and antioxidants were included. Research conducted on adults or on animals or review articles, and articles in which only their abstracts were available were excluded. The quality of the reported studies was also assessed.

Results: Out of 980 searched articles, 13 articles (10 prospective articles and 3 cross-sectional articles) were studied. An increase in antioxidant enzymes (Glutathione peroxidase (GSH-Px), catalase (CAT) and Plasma superoxide dismutase (SOD)) cannot be dealt with excessive oxidants produced in the body (Plasma and cerebrospinal fluid levels of Malondialdehyde (MDA), free radical products (F8-isoprostane and MDA), saturated fatty acids and % CoQ-10). Prooxidant anti-oxidant balance (PAB) levels among neonates who had asphyxia were announced to be two times higher than normal newborns. PAB values in neonates with asphyxia, who had adverse prognosis, were about three times higher than those with favorable prognosis. The sensitivity of PAB in predicting the prognosis of neonates with asphyxia was reported 83- 89% and its specificity was 71- 92%. The pooled SMD analysis revealed a significant association between PAB and MDA levels with the risk of prenatal asphyxia both overall (SMD = 1.447, 95%CI: 0.961-1.934, P < 0.001), as well as separately in subgroups of PAB (SMD = 1.134, 95%CI: 0.623-1.644, P < 0.001) and MDA (SMD = 1.910, 95%CI: 0.916-2.903, P < 0.001).

Conclusion: Our meta-analysis findings revealed the potential of evaluating antioxidant enzymes and oxidant agents, as well as assessing the balance between them (PAB), in diagnosing and predicting the prognosis of neonatal asphyxia. The limitations of the present study included not having access to all related complete articles, lack of quality and usability in reports of some articles, and the different diagnostic methods of prenatal asphyxia in different studies.