A disproportionate increase in IL-1beta over IL-1ra in the cervicovaginal secretions of pregnant women with altered vaginal microflora correlates with preterm birth.
OBJECTIVE
This purpose of this study was to investigate the association between vaginal microflora, concentrations of interleukin-1beta (IL-1beta), and its natural receptor antagonist (IL-1ra) in the cervicovaginal discharge, and spontaneous preterm birth. Study design Vaginal samples collected at 18 to 22 weeks' gestation from 207 women were analyzed to study qualitative and quantitative microbiologic aspects of vaginal microflora and IL-1beta and IL-1ra concentrations.


RESULTS
Among women colonized with anaerobic Gram-negative rods and/or Gardnerella vaginalis, an elevated IL-1beta concentration, or a diminished IL-1ra:IL-1beta ratio were associated with preterm delivery. A cut-off IL-1ra:IL-1beta ratio of <8632:1 optimally discriminated the subjects with subsequent spontaneous preterm deliveries from subjects who delivered at term, with a sensitivity of 78%, specificity of 51%, positive predictive value of 21%, and negative predictive value of 95%.


CONCLUSIONS
A disproportionate increase in IL-1beta over IL-1ra in response to vaginal colonization with anaerobic Gram-negative rods and/or G. vaginalis at 18 to 22 weeks' gestation is associated with spontaneous preterm delivery.
Genc
Mehmet R
MR
Department of Obstetrics, Gynecology and Reproductive Biology, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts 02115, USA. mgencmd@yahoo.com
Witkin
Steven S
SS
Delaney
Mary L
ML
Paraskevas
Lilly-Rose
LR
Tuomala
Ruth E
RE
Norwitz
Errol R
ER
Onderdonk
Andrew B
AB
D000328:Adult; D015415:Biomarkers / Q000032:analysis; D002584:Cervix Uteri / Q000166:cytology / Q000382:microbiology*; D015331:Cohort Studies; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D007234:Infant, Premature; D007375:Interleukin-1 / Q000032:analysis*; D016015:Logistic Models; D007752:Obstetric Labor, Premature / Q000175:diagnosis*; D011247:Pregnancy; D011256:Pregnancy Outcome; D011262:Pregnancy Trimester, Second; D011336:Probability; D018570:Risk Assessment; D012680:Sensitivity and Specificity; D018709:Statistics, Nonparametric; D014626:Vaginal Smears; D016585:Vaginosis, Bacterial / Q000150:complications / Q000382:microbiology*
D015415:Biomarkers; D007375:Interleukin-1