Inflammatory changes in the plasma and cerebrospinal fluid of patients with persistent pain and postpartum depression after elective Cesarean delivery: an exploratory prospective cohort study; [Changements inflammatoires dans le plasma et le liquide céphalorachidien des patient·es souffrant de douleur persistante et de dépression post-partum après un accouchement par césarienne programmée : une étude de cohorte prospective exploratoire]

Purpose: Severe acute pain after Cesarean delivery increases the risk of developing persistent pain (~20% incidence) and postpartum depression (PPD) (~15% incidence). Both conditions contribute to maternal morbidity and mortality, yet early risk stratification remains challenging. Neuroinflammation has emerged as a key mechanism of persistent pain and depression in nonobstetric populations. Nevertheless, most studies focus on plasma cytokines, and the relationship between plasma and cerebrospinal fluid (CSF) cytokine levels is unclear. Our primary aim was to compare inflammatory marker levels between patients who developed the composite outcome of persistent pain and/or PPD vs those who did not. Methods: We recruited term patients with singleton pregnancies undergoing elective Cesarean delivery under neuraxial anesthesia into an exploratory prospective cohort study. We collected baseline demographic, obstetric, and Edinburgh Postnatal Depression Scale information, and performed quantitative sensory tests. Plasma was collected preoperatively and 48 hr postoperatively. In the operating room, 10 mL of CSF was collected, followed by a standardized anesthetic. Intra- and postoperative management were according to standard practice. We obtained Edinburgh Postnatal Depression Scale and pain scores at six weeks and three months after delivery. The primary outcome was persistent pain and/or PPD at three months. We analyzed the difference in inflammatory marker levels between the groups (primary aim) using two-sided Mann–Whitney tests. Results: Eighty participants were enrolled, and 63 patients completed the study; 23 (37%) experienced the primary outcome at three months. Preoperative plasma transforming growth factor beta 1 (TGF-β1) concentration was higher in patients who developed the primary outcome compared with those who did not (median [interquartile range (IQR)], 2,879 [2,241–5,494] vs 2,292 [1,676–2,960] pg·mL−1; P = 0.04), while CSF IL-1β concentration was higher in patients who developed the primary outcome than in those who did not (median [IQR], 0.36 [0.29–0.39] vs 0.30 [0.25–0.35] pg·mL−1; P = 0.03). Conclusions: We observed differential levels of plasma and CSF inflammatory biomarkers in patients who developed persistent pain and PPD compared with those who did not. We showed the feasibility of collecting plasma and CSF samples at Cesarean delivery, which may prove useful for future risk-stratification. Study registration: ClinicalTrials.gov (NCT04271072); registered 17 February 2020. © 2023, Canadian Anesthesiologists' Society.