MATERNAL SERUM INTERLEUKIN-6 DURING PREGNANCY AND DURING TERM AND PRETERM LABOR

Objective: To determine the normal concentrations of maternal serum in terleukin-6 during the second and third trimesters of pregnancy and th e different stages of term and preterm labor, and to examine the clini cal usefulness of measuring this cytokine in the serum of women in pre term labor to diagnose asymptomatic intrauterine infections. Methods: Maternal serum interleukin-6 concentrations were measured cross-sectio nally in 315 gravidas in their second and third trimesters and during term and preterm labor. Placentas from women who delivered preterm wer e examined for histologic chorioamnionitis. Results: At term, women in labor had significantly elevated median maternal serum interleukin-6 concentrations compared with those at term not in labor (4.7 pg/mL ver sus 2.2 pg/mL, P < .001). Women admitted in preterm labor who delivere d had significantly higher median interleukin-6 concentrations than di d those in preterm labor who responded to tocolysis (9.3 pg/mL versus 1.9 pg/mL, P < .001). Women in preterm labor who delivered preterm wit h evidence of chorioamnionitis had significantly higher serum concentr ations of interleukin-6 than did those in preterm labor who delivered in the absence of chorioamnionitis (15.9 pg/mL versus 4.6 pg/mL, P = . 006). Conclusion: Compared with antepartum gravidas, those in term or preterm labor had significantly higher concentrations of maternal seru m interleukin-6 concentrations; extremely elevated levels were found i n patients whose preterm labor was associated with intrauterine infect ion. ((C) 1997 by The American College of Obstetricians and Gynecologi sts).