Blood Count Ratios and Postpartum Depressive Symptoms: Findings from a Homogeneous Sample of First-Time Mothers

OBJECTIVE: Postpartum depressive symptoms are a common psychiatric condition with multifactorial aetiology. Haematological inflammatory markers such as neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and monocyte-to-lymphocyte ratio (MLR) have been proposed as indicators of systemic inflammation in mood disorders. This study aimed to investigate the association, rather than causality, between these markers and postpartum depressive symptoms in a homogeneous sample of first-time mothers. METHODS: In this cross-sectional observational study, 92 primiparous women attending a routine two-week postpartum follow-up were evaluated. Inclusion criteria included age ≥18 years, singleton term pregnancy, and attendance at postpartum follow-up. Depressive symptoms were assessed using the validated Turkish Edinburgh Postnatal Depression Scale (EPDS), with a cut-off score of 12 or higher. Complete blood count parameters were analysed, and NLR, PLR and MLR were calculated. Statistical analyses included independent samples t-tests, Mann-Whitney U tests, chi-square tests, and binary logistic regression analysis. RESULTS: Maternal and neonatal characteristics were comparable between groups. NLR, PLR and MLR values did not differ significantly. Logistic regression analysis showed that none of these markers were independent predictors of postpartum depressive symptoms (all p > 0.05). CONCLUSION: In this study, NLR, PLR and MLR were not associated with postpartum depressive symptoms. These findings suggest that simple blood count-derived ratios may have limited utility as standalone indicators of postpartum depressive symptoms.