Biomarkers of oxidative stress in maternal plasma, umbilical cord and placenta of patients with gestational diabetes: a systematic review and meta-analysis

OBJECTIVE: To determine the association between Gestational Diabetes Mellitus (GDM) and oxidative stress biomarkers in the mother, placenta, and newborn. METHODS: We conducted a systematic review and meta-analysis following the PRISMA guidelines. We searched PubMed/MEDLINE and the Web of Science database without language restrictions. The search was updated on December 28, 2023, and included reports published between 1998 and 2021. Two independent reviewers performed article selection and data extraction. RESULTS: Our findings show a significant increase in malondialdehyde and 8-isoprostane levels in the maternal plasma and placenta of women with GDM compared to those without GDM (SMD [95 % CI] = 1.99 [1.51, 2.48], Tau2 = 1.51, I2 = 94 %, p < 0.00001; SMD [95 % CI] = 1.90 [0.08, 2.72], Tau2 = 1.14, I2 = 93 %, p < 0.00001, respectively). Additionally, there was a decrease in superoxide dismutase (SOD) levels in maternal plasma (SMD [95 % CI] = -2.80 [-5.23, -0.36], Tau2 = 7.56, I2 = 98 %, p < 0.00001). However, no significant changes in SOD were observed in the placenta or the umbilical cord blood of offspring from women with GDM (SMD [95 % CI] = -1.79 [-4.66, 1.07], Tau2 = 6.23, I2 = 97 %, p < 0.00001; SMD [95 % CI] = -1.07 [-3.37, 1.24], Tau2 = 5.31, I2 = 97 %, p < 0.00001, respectively). CONCLUSION: These results suggest an association between GDM and increased oxidative stress levels in both maternal and fetal circulation, as well as the placenta. The high heterogeneity in the results of the meta-analysis, which could be due to clinical and methodological factors, is a limitation of this study.