['We examined depressive symptoms, C-reactive protein (CRP), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) levels during early to-midgestation.', 'We measured depressive symptoms on the Patient Health Questionnaire-9 (PHQ-9), and serum CRP, IL-6, and TNF-α levels twice in 27 pregnant women.', 'After adjustment, depressive symptoms prospectively (β=0.42, p<0.05 at 16-20 weeks of gestation) and concurrently (β=0.54, p<0.01 at 7-10 weeks of gestation) predicted elevated CRP [F (2, 14)=9.20, p=0.003, R(2)=0.57 and F (3, 15)=9.08, p=0.001, R(2)=0.64, respectively]. There were similar patterns of results for TNF-α (β=0.72, p<0.01) and IL-6 levels (β=0.39, p<0.05) at 7-10 weeks of gestation [F (2,19)=8.84, p=0.002, R(2)=0.48]. Furthermore, the association between depressive symptoms at 7-10 weeks of gestation and increased IL-6 levels at 16-20 weeks of gestation approached statistical significance. We confirmed the findings with the Wilcoxon signed rank test (IL-6: Z=2.44, p=0.015; TNF-α: Z=1.94, p=0.05; CRP: approached statistical significance).'] Are mild depressive symptoms associated with elevated C-reactive protein and proinflammatory cytokine levels during early to midgestation : a prospective pilot study?