Preterm Prelabor Rupture of Membranse between 34 and 37 Weeks: A Point-of-Care Test of Vaginal Fluid Interleukin-6 Concentrations for a Noninvasive Detection of Intra-Amniotic Inflammation
Abstract
The aim of this study was to investigate whether a previously reported vaginal fluid point-of-care interleukin (IL)-6 cut-off value of 2,500 pg/mL can be used for the identification intra-amniotic inflammation in women with preterm prelabor rupture of membranes (PPROM) between 34 and 37 weeks. A prospective cohort study was conducted in women with singleton gestation complicated by PPROM between 34 + 0 and 36 + 6 weeks.
Vaginal fluid was successfully obtained in 118 women from the posterior vaginal fornix via aspiration using a sterile urine sample tube with a suction tip. Amniotic fluid was obtained via transabdominal amniocentesis.
IL-6 concentrations were assessed in both fluids immediately after sampling. Intra-amniotic inflammation was defined as an amniotic fluid point-of-care IL-6 concentration >=745 pg/mL.
The tested vaginal fluid IL-6 cut-off value had a sensitivity of 91%, specificity of 91%, positive predictive value of 50%, negative predictive value of 99%, positive likelihood ratio of 9.7, and negative likelihood ratio of 0.1 for the identification of intra-amniotic inflammation. The point-of-care vaginal fluid IL-6 test with a cut-off value of 2,500 pg/mL shows good sensitivity, specificity, and negative predictive value for the identification of intra-amniotic inflammation in PPROM between 34 and 37 weeks.