[Maternal serum cytokines in labor, pregnancy and chorioamnionitis]

The purpose of our study was to compare maternal serum levels of interleukin-6, interleukin-8, tumor necrosis factor-alpha and interferon-gamma in gravidities, during spontaneous term and preterm labor and their relation to histologic chorioamnionitis.

We investigated 61 women: 10 in preterm labor, 36 in term labor and 15 healthy pregnant nonlabouring controls. Venous bloods for cytokines determinations were obtained during the first stage of labor and during routine screening tests. Titers of cytokines were measured by means of ELISA technique. All births after preterm deliveries were examined to establish histologic chorioamnionitis.

Serum levels of IL-6 and IL-8 were significantly elevated both in term (mean: IL-6: 17.5 +/- 58 pg/ml; IL-8: 148 +/- 215 pg/ml) and preterm labor (IL-6: 23 +/- 44 pg/ml; IL-8: 332 +/- 389 pg/ml) when compared to nonlabouring gravidities (IL-6: 5 +/- 7 pg/ml; IL-8: 14 +/- 11 pg/ml). IL-6 and IL-8 titers were statistically similar in term and preterm labors and in patients with and without histologic chorioamnionitis. TNF-alpha and IFN-gamma were not statistically analyzed because only a few patients had detectable serum levels of these cytokines.

Serum levels of IL-6 and IL-8 in both: term and preterm labor are elevated in comparison to nonlabouring gravidities. The elevated levels of these cytokines are not connected with coexisting chorioamnionitis.