Do pregnant women with depression have a pro-inflammatory profile?

We tested the hypothesis that maternal depression is associated with a pro-inflammatory state in pregnancy.

In this nested case-control study, pro-inflammatory cytokine levels were compared between women with depression in pregnancy (n = 100) and a computer-generated referent group of healthy women known not to be depressed (n = 100). We only included cases with a documented Diagnostic and Statistical Manual of Mental Disorders depression diagnosis in the current pregnancy. Serum samples drawn at 11-14 weeks of gestation were analyzed for levels of tumor necrosis factor-alpha and interleukin-6 using high-sensitivity immunoassays.

Maternal demographics were similar between the groups except for older age (34.1 vs 32.7 years, P = .05), and lower body mass index (27.3 vs 28.9 kg/m², P = 0.03) among the depressed subjects. Compared to control women, tumor necrosis factor-alpha (5.8 ± 3.4 vs 3.2 ± 2.8 pg/ml, P < 0.0001) and interleukin-6 (2.4 ± 3.8 vs 1.5 ± 1.4 pg/ml, P = 0.03) levels were higher among women with depression. The higher rate of inflammatory cytokines remained significant after controlling for potential confounders, including maternal age and body mass index.

Women with depression may have higher levels of inflammatory markers in early pregnancy. Our findings support the hypothesis that inflammation may be a mediator in the association between maternal depression and adverse perinatal outcomes.