Maternal inflammatory markers and term labor performance.

OBJECTIVE: We sought to examine the relationship between maternal markers of inflammation and labor performance. STUDY DESIGN: A nested cohort study was performed utilizing an established cohort of term nulliparous patients. Maternal blood was collected at the onset of regular, painful contractions in patients undergoing labor induction or at admission in patients with spontaneous labor. Levels of cytokines including interleukin (IL)-1, IL-6, and tumor necrosis factor-α were determined using standard multiplex methodology. Maternal demographic data were collected prospectively. Detailed retrospective chart review was performed to extract data on cervical dilation, effacement, and station during labor. Subjects were excluded if they failed to achieve complete dilation. Mixed effects modeling was used to examine the association between serum cytokine quartiles and labor progress in the latent and active phases. RESULTS: In all, 334 women were included in our analysis. The lowest quartile of IL-6 was associated with slower latent labor (P = .001). In contrast, the highest quartiles of IL-1 and tumor necrosis factor-α were associated with slower active labor (P = .03 and .0002, respectively). CONCLUSION: Proinflammatory activation is important in labor initiation. However, once active labor is established, excess inflammation can be detrimental to efficient labor progress. These data may explain, in part, the known associations among clinical chorioamnionitis, cesarean delivery, and postpartum hemorrhage.

Maternal inflammation in spontaneous term labor.

OBJECTIVE: The purpose of this study was to examine the association between peripheral markers of maternal inflammation and the onset of term labor. STUDY DESIGN: A nested case-control study was performed with serum that had been collected at routine visits from a cohort of 607 term nulliparous women. Cases (n = 20) labored spontaneously within 48 hours of enrollment, and control subjects (n = 80) labored spontaneously ≥14 days after enrollment. Maternal serum cytokines were determined with the use of standard multiplex protocols. Median levels of interleukin-1, -4, -6, -8, and -10, interferon-γ, and tumor necrosis factor-α were compared with the use of the Mann-Whitney U test. Correlations between cytokine levels and maternal factors were performed (Spearman's rho). RESULTS: Median interleukin-1 and -6 and tumor necrosis factor-α levels were significantly higher in cases vs control subjects (0.76 vs 0.31 pg/mL [P < .01]; 2.05 vs 0.95 pg/mL [P = .03]; 0.81 vs 0.51 pg/mL [P = .02], respectively). Latency until delivery was inversely correlated with interleukin-1 and tumor necrosis factor-α (-0.28 [P < .01]; -0.246 [P = .01]), but not with interleukin-6. CONCLUSION: Maternal proinflammatory markers increase before spontaneous term labor.