ELEVATED 2ND-TRIMESTER AMNIOTIC-FLUID INTERLEUKIN-6 LEVELS PREDICT PRETERM DELIVERY

OBJECTIVE: Out purpose was to determine whether early second-trimester amniotic fluid interleukin-6 levels predict delivery before 34 weeks' gestation. STUDY DESIGN: We used stored second-trimester amniotic flu id samples obtained from women undergoing genetic amniocentesis from 1 988 to 1996. Interleukin-6 levels were measured by enzyme-linked immun osorbent assay in samples from every case known to result in delivery from 20 to 34 weeks' gestation (n = 290), and 290 matched controls del ivering at greater than or equal to 37 weeks. Fetal aneuploidies, anom alies, and all cases delivering within 30 days of the amniocentesis (w hich were thought to be possibly procedure related) were excluded. RES ULTS: Interleukin-8 levels were higher in cases than controls (1.9 +/- 5.2 vs 1.0 +/- 2.4 ng/ml, p = 0.004). Cases were grouped according to whether the preterm delivery was indicated or spontaneous: The mean i nterleukin-6 levels were significantly higher than controls in the spo ntaneous group (1.6 +/- 3.2 vs 0.8 +/- 1.2 ng/ml, p = 0.01) but not in the indicated group (1.4 +/- 4.0 vs 0.8 +/- 1.2 ng/ml, p = 0.12). In all samples the interleukin-6 level was negatively correlated with the gestational age at delivery (R = -0.11633, p = 0.007). CONCLUSION: El evated early second-trimester amniotic fluid interleukin-6 levels are associated with preterm delivery confirming that in some women this in dicator of very early intrauterine inflammation predicts birth before 34 weeks' gestation.