Exploring biomarkers of systemic oxidative stress and placental insufficiency in pregnant women with inflammatory bowel diseases

Background: Inflammatory bowel disease (IBD) often presents during the fertile age and may affect pregnancy outcomes. Both IBD and selected pregnancy complications involve oxidative stress. Soluble FMS-like tyrosine kinase-1 (sFlt-1) and placental growth factor (PlGF) serve as biomarkers of placental insufficiency, while free thiols (FT) reflect systemic oxidative stress. This study aimed to assess the dynamics of FT, sFlt-1, and PlGF before, during, and shortly after pregnancy, and their relationships with disease- and pregnancy outcomes in patients with IBD. Methods: This retrospective cohort study included pregnant women with and without IBD. FTs were measured with colorimetric detection; sFlt-1 and PlGF were measured using immunofluorescent assays. Extensive clinical data were collected, including pregnancy complications and IBD parameters. Results: A total of 40 patients and 14 non-IBD controls participated, covering 57 IBD and 14 control pregnancies. Serum FT levels were significantly lower in patients with ulcerative colitis during pregnancy (p = 0.007) and decreased compared to pre-conceptional levels (p = 0.005), indicating increased oxidative stress. sFlt-1/PlGF ratios were higher in patients with small-for-gestational-age infants (p = 0.015). Post-pregnancy FT levels were lower in patients experiencing disease exacerbations during pregnancy (p = 0.046), whereas sFlt-1/PlGF ratios were numerically higher (p = 0.063). IBD severity correlated with lower FT levels regarding surgical history (p = 0.066) and biologic use (p = 0.033). Conclusions: This study demonstrates increased systemic oxidative stress in patients with IBD during pregnancy, as reflected by lower FT levels compared to pre-conceptional values and non-IBD controls. Prospective validation is required to evaluate the utility of these biomarkers in predicting pregnancy complications and informing clinical decisions.