Background: To find out whether preterm labor is associated with raised maternal serum concentrations of interleukin (IL)-6, IL-8, tumor necrosis factor alpha (TNF-alpha) and interferon gamma (IFN-gamma) and whether the measurement of these cytokines can be used to detect early intrauterine infection in preterm labor.
Methods: Cross-sectional study: 77 women in preterm labor, 47 controls of healthy preterm women not in labor and 19 women in term labor. The serum cytokines levels were measured by enzyme-linked immunosorbent assay (ELISA). The newborns of women who were in labor were followed up for evidence of infection. Differences between groups were tested using analysis of variance, Student's t-test and chi2-test.
Results: There was no significant difference in the concentration of all the cytokines measured between the different groups. No statistical difference was found in the concentration of the cytokines between women in preterm labor with ruptured membranes and those with intact membranes. There was also no difference found in the concentration of cytokines between women whose newborns had positive bacterial culture and those with negative culture. There was a positive correlation between the concentrations of IL-6, IL-8 and TNF-alpha.
Conclusion: Serum levels of interleukin-6, interleukin-8 and tumor necrosis factor-alpha were not increased in preterm labor compared to normal control women. There is doubt regarding the usefulness of maternal serum measurement of these cytokines for the detection of early fetal infection in preterm labor, but this needs further evaluation.