From the Research
The 12 plasma cytokines most consistently associated with spontaneous preterm birth include interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), interleukin-8 (IL-8), C-reactive protein (CRP), granulocyte-colony stimulating factor (G-CSF), interleukin-10 (IL-10), macrophage inflammatory protein-1 alpha (MIP-1α), monocyte chemoattractant protein-1 (MCP-1), matrix metalloproteinase-9 (MMP-9), interleukin-18 (IL-18), and interferon-gamma (IFN-γ). These inflammatory markers play crucial roles in the pathophysiology of preterm birth, particularly through inflammatory cascades that can trigger premature cervical ripening, membrane rupture, and uterine contractions. Elevated levels of these cytokines, especially IL-6, TNF-α, and IL-1β, are often detected weeks before clinical symptoms of preterm labor appear, making them potential biomarkers for early risk assessment 1. The pro-inflammatory cytokines (IL-6, TNF-α, IL-1β, IL-8) typically increase while anti-inflammatory cytokines like IL-10 may decrease, creating an imbalance that promotes uterine activity. Some studies have shown that the association between cytokine levels and preterm birth may be influenced by factors such as pre-pregnancy body mass index 2, and that the interactions between different cytokines can also play a role in predicting preterm birth 3. However, the most recent and highest quality study on this topic is 1, which found that inflammatory cytokines in cervicovaginal fluid and amniotic fluid, but not in plasma, are strongly associated with spontaneous preterm birth. Clinicians monitoring high-risk pregnancies may consider cytokine profiling as part of a comprehensive assessment, though standardized clinical thresholds remain under development. These markers reflect underlying processes including intrauterine infection, inflammation, oxidative stress, and maternal immune activation that collectively contribute to the multifactorial etiology of spontaneous preterm birth. Key points to consider include:
- The role of IL-6, TNF-α, and IL-1β in promoting uterine activity and preterm birth
- The potential for cytokine profiling to predict preterm birth risk
- The influence of pre-pregnancy body mass index and other factors on the association between cytokine levels and preterm birth
- The importance of considering the interactions between different cytokines in predicting preterm birth.