CLINICAL-VALUE OF AMNIOTIC-FLUID INTERLEUKIN-6 DETERMINATIONS IN THE MANAGEMENT OF PRETERM LABOR

Objective To ascertain whether the determination of amniotic fluid int erleukin-6 (IL-6) concentrations would be a useful clinical test in th e management of women with preterm contractions. Setting The labour an d delivery unit and the Fetal Diagnostic Centre at the University of U tah. Subjects Pregnant women at various stages of gestation in the thi rd trimester.Design Amniotic fluid samples were collected from women e xperiencing one of four clinical scenarios: 1. term pregnancy, not in labour with no evidence of intrauterine infection; 2. normal term labo ur with no evidence of infection; 3. preterm labour with no evidence o f infection and undelivered within one week of sampling; and 4. preter m labour and delivered within seven days of sample collection. Amnioti c fluid was obtained by amniocentesis or at the time of amniotomy or h ysterotomy. IL-6 in each specimen was determined by a specific rapid E LISA. Results Amniotic fluid IL-6 levels, given as mean (SEM) in the f our groups of women listed were: 1. term pregnancy, not in labour: 20. 9 (7.2) pg/ml (n = 60); 2. normal term labour with no infection: 554(9 0.7)pg/ml (n = 46); 3. preterm labour with no evidence of infection, u ndelivered: 47.0 (17.2) pg/ml (n = 35); and 4. preterm labour, deliver ed: 456.7 (101.7) pg/ml (n = 40). There was no significant difference in the means of amniotic fluid IL-6 for the term labour and preterm la bour delivered groups. In general, amniotic fluid IL-6 levels during t erm labour increased with advancing cervical dilation. There was no co rrelation of cervical dilation and amniotic fluid IL-6 levels in women having preterm delivery. Receiver-operator curves revealed optimal IL -6 levels for discrimination of labour at term to be 50 pg/ml and for preterm delivery to be 200 pg/ml. Conclusions IL-6 can readily be dete cted in the amniotic fluid of most women who are in active labour, reg ardless of gestational age. Our data suggest that amniotic fluid IL-6 determinations may be clinically useful in the management of preterm l abour.