Preterm Prelabor Rupture of Membranes between 34 and 37 Weeks: A Point-of-Care Test of Vaginal Fluid Interleukin-6 Concentrations for a Noninvasive Detection of Intra-Amniotic Inflammation.

OBJECTIVE: 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. MATERIAL AND METHODS: 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 of ≥745 pg/mL. RESULTS: 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. CONCLUSION: 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.

Maternal serum C-reactive protein concentration and intra-amniotic inflammation in women with preterm prelabor rupture of membranes.

OBJECTIVE: To evaluate maternal serum C-reactive protein (CRP) concentrations in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) in relation to the presence of microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI). METHODS: Two hundred and eighty-seven women with singleton pregnancies complicated by PPROM between 2014 and 2016 were included in this study. Maternal blood and amniotic fluid samples were collected at the time of admission. Maternal serum CRP concentration was measured using a high-sensitivity immunoturbidimetric assay. Interleukin-6 (IL-6) concentration was measured using a point-of-care test. MIAC was diagnosed based on a positive polymerase chain reaction result for Ureaplasma species, Mycoplasma hominis, and/or Chlamydia trachomatis and for the 16S rRNA gene. IAI was characterized by an amniotic fluid IL-6 concentration of ≥ 745 pg/mL. RESULT: Women with MIAC and IAI had higher maternal serum CRP concentrations than did women without (with MIAC: median 6.9 mg/L vs. without MIAC: median 4.9 mg/L; p = 0.02; with IAI: median 8.6 mg/L vs. without IAI: median 4.7 mg/L; p < 0.0001). When women were split into four subgroups based on the presence of MIAC and/or IAI, women with the presence of both MIAC and IAI had higher maternal serum CRP than did women with IAI alone, with MIAC alone, and women without MIAC and IAI (both MIAC and IAI: median: 13.1 mg/L; IAI alone: 6.0 mg/L; MIAC alone: 3.9 mg/L; and without MIAC and IAI: median 4.8 mg/L; p < 0.0001). The maternal serum CRP cutoff value of 17.5 mg/L was the best level to identify the presence of both MIAC and IAI, with sensitivity of 47%, specificity of 96%, positive predictive value of 42%, negative predictive value of 96%, and the positive likelihood ratio of 10.9. CONCLUSION: The presence of both MIAC and IAI was associated with the highest maternal serum CRP concentrations. Maternal serum CRP concentration in women with PPROM at the time of admission can rule out the presence of the combined condition of both MIAC and IAI, therefore, it may serve as a non-invasive screening tool to distinguish between women with PPROM who are at high or at low risk for the presence of both MIAC and IAI.

Transabdominal Amniocentesis Is a Feasible and Safe Procedure in Preterm Prelabor Rupture of Membranes.

OBJECTIVES: To determine the feasibility and the complication rate of amniocentesis in a large cohort of women with preterm prelabor rupture of membranes (PPROM). METHODS: A retrospective cohort study was conducted in all women with singleton gestation complicated by PPROM at between 24+0 and 36+6 weeks admitted to the Department of Obstetrics and Gynecology, University Hospital Hradec Kralove, Czech Republic between May 2008 and July 2016. Amniocentesis was offered as a part of a routine protocol of PPROM for the detection of microbial invasion of the amniotic cavity and intra-amniotic inflammation. Procedure was performed under ultrasound guidance. A successful procedure was defined as obtaining at least 0.5 mL of amniotic fluid. No more than 2 attempts were performed. RESULTS: In total, 590 women with PPROM were included. Amniocentesis was successful in 96% (567/590). Two amniocentesis attempts were necessary in 9% (55/590) and the transplacental approach was used in 13% (76/590). No association between gestational age at sampling and the amniocentesis failure rate was found (Spearman rho -0.12; p = 0.71). The complication rate was 0.7% (4/590). Two umbilical cord punctures and 2 chorionic plate fetal vessel injuries occurred, without fetal morbidity. CONCLUSION: Based on our study population, so far the largest published, amniocentesis is a feasible and safe procedure carrying a very low risk of failure or complications in PPROM.

Amniotic fluid cathepsin-G in pregnancies complicated by the preterm prelabor rupture of membranes.

OBJECTIVE: The aim of this study was to evaluate the amniotic fluid cathepsin-G concentrations in women with preterm prelabor rupture of membranes (PPROM) based on the presence of the microbial invasion of the amniotic cavity (MIAC) and/or intra-amniotic inflammation (IAI). METHODS: A total of 154 women with singleton pregnancies complicated by PPROM were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis. Amniotic fluid cathepsin-G concentrations were assessed by ELISA. MIAC was determined using a non-cultivation approach. IAI was defined as an amniotic fluid bedside interleukin-6 concentration ≥ 745 pg/mL. RESULTS: Women with MIAC had higher amniotic fluid cathepsin-G concentrations than women without MIAC (with MIAC: median 82.7 ng/mL, versus without MIAC: median 64.7 ng/mL; p = 0.0003). Women with IAI had higher amniotic fluid cathepsin-G concentrations than women without this complication (with IAI: median 103.0 ng/mL, versus without IAI: median 66.2 ng/mL; p < 0.0001). Women with microbial-associated (with both MIAC and IAI) IAI and sterile (IAI without MIAC) IAI had higher amniotic fluid cathepsin-G concentrations than women with colonization (MIAC without IAI) and women without both MIAC and IAI (p < 0.0001). CONCLUSIONS: The presence of either microbial-associated or sterile IAI was associated with increased amniotic fluid cathepsin-G concentrations in pregnancies complicated by PPROM. Amniotic fluid cathepsin-G appears to be a potential marker of IAI.

Amniotic fluid clusterin in pregnancies complicated by the preterm prelabor rupture of membranes.

OBJECTIVE: The aim of this study was to evaluate clusterin concentrations in amniotic fluid in pregnancies complicated by preterm prelabor rupture of membranes (PPROM) with respect to the presence of the microbial invasion of the amniotic cavity (MIAC), intra-amniotic inflammation (IAI) and microbial-associated IAI. METHODS: One hundred thirty-six women with singleton pregnancies complicated by PPROM were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis. Amniotic fluid clusterin concentrations were assessed by enzyme-linked immunosorbent assay. MIAC was determined by a non-cultivation approach. IAI was defined as an amniotic fluid bedside interleukin-6 concentration ≥745 pg/mL. Microbial-associated IAI was characterized as the presence of both MIAC and IAI. RESULT: Women with MIAC, IAI and microbial-associated IAI had lower amniotic fluid clusterin concentrations than women without these complications (with MIAC: median 1314 ng/mL versus without MIAC: median 1633 ng/mL, p = 0.003; with IAI: median 1281 ng/mL versus without IAI: median 1575 ng/mL, p = 0.04; with microbial associated-IAI: median 1220 ng/mL versus without microbial-associated IAI: median 1575 pg/mL; p = 0.008). A week negative correlation between amniotic fluid clusterin concentrations and gestational age at sampling was revealed (rho= -0.30; p = 0.0005). CONCLUSIONS: The presence of MIAC, IAI and microbial-associated IAI was characterized by lower amniotic fluid clusterin concentrations in pregnancies complicated by PPROM.

Intraamniotic inflammation and umbilical cord blood interleukin-6 concentrations in pregnancies complicated by preterm prelabor rupture of membranes.

OBJECTIVE: To evaluate umbilical cord blood interleukin (IL)-6 concentrations and the occurrence of fetal inflammatory response syndrome (FIRS) with respect to microbial invasion of the amniotic cavity (MIAC) and/or intraamniotic inflammation (IAI) in pregnancies complicated by preterm prelabor rupture of membranes (PPROM). METHODS: One-hundred-eighty-eight women with singleton pregnancies complicated by PPROM between gestational ages of 24 + 0 and 36 + 6 weeks were included in the study. Blood samples were obtained by venipuncture from the umbilical cord after the delivery of the newborn. The umbilical cord blood IL-6 concentrations were evaluated using ELISA kits. FIRS was defined as umbilical cord blood IL-6 > 11 pg/mL. RESULT: Women with MIAC and IAI had higher IL-6 concentrations than women without these complications (with MIAC: median 18.1 pg/mL versus without MIAC: median 5.8; p < 0.0001; with IAI: median 32.9 pg/mL, versus without IAI: median 5.8; p < 0.0001). Women with IAI with MIAC and women with IAI without MIAC had the highest umbilical cord blood IL-6 concentrations (medians: 32.6 and 39.4 pg/mL) and rates of FIRS (78% and 67%). CONCLUSIONS: IAI was associated with the highest umbilical cord blood IL-6 concentrations and rate of FIRS independent of the presence or absence of MIAC.

Vaginal fluid IL-6 concentrations as a point-of-care test is of value in women with preterm PROM.

BACKGROUND: Preterm prelabor rupture of membranes (PROM) is frequently complicated/accompanied by infection and inflammation in the amniotic cavity. A point-of-care determination of amniotic fluid interleukin-6 has been shown to be a potentially clinically useful approach to assess inflammatory status of the amniotic cavity. Amniocentesis in preterm PROM is not broadly used in clinical practice, and therefore a shift towards a non-invasive amniotic fluid sampling method is needed. OBJECTIVE: The first aim of this study was to evaluate the association between the point-of-care vaginal and amniotic fluid interleukin-6 concentrations in fresh unprocessed samples obtained simultaneously. The second goal was to determine the diagnostic indices and predictive value of the point-of-care assessment of vaginal fluid interleukin-6 concentration in the identification of microbial invasion of the amniotic cavity, intra-amniotic inflammation, and microbial-associated intra-amniotic inflammation in patients with preterm PROM. STUDY DESIGN: A prospective cohort study was conducted in women with singleton gestation complicated by preterm PROM at between 24+0 and 36+6 weeks. A total of 153 women with singleton pregnancies were included in this study. Vaginal fluid was obtained from the posterior vaginal fornix by aspiration with a sterile urine sample tube with a suction tip. Amniotic fluid was obtained by transabdominal amniocentesis. Interleukin-6 concentrations were assessed with a lateral flow immunoassay in both fluids immediately after sampling. Microbial invasion of the amniotic cavity was determined based on a positive PCR analysis. Intra-amniotic inflammation was defined as an amniotic fluid point-of-care interleukin-6 concentration ≥745 pg/mL. RESULTS: 1) It was possible to perform the point-of-care assessment of interleukin-6 in vaginal fluid in 92% (141/153) of the women, and only those women were included in the analyses. 2) The rate of microbial invasion of the amniotic cavity and intra-amniotic inflammation was 26% (36/141) and 19% (27/141), respectively. Microbial-associated intra-amniotic inflammation was identified in 12% (17/141) of the women. 3) A strong positive correlation was found between the interleukin-6 concentrations in vaginal and amniotic fluids (Spearman rho 0.68; p<0.0001). 4) The presence of microbial invasion of the amniotic cavity, intra-amniotic inflammation or microbial-associated intra-amniotic inflammation was associated with higher vaginal fluid interleukin-6 concentrations in both crude and adjusted analyses. 5) A vaginal fluid interleukin-6 concentration of 2500 pg/mL was determined to be the best cutoff value for the identification of microbial invasion of the amniotic cavity [sensitivity of 53% (19/36), specificity of 89% (93/104), positive predictive value of 63% (19/30), negative predictive value of 85% (93/110), positive likelihood ratio of 5.0 (95% CI 2.5-9.5), and negative likelihood ratio of 0.5 (95% CI 0.4-0.8)], intra-amniotic inflammation [sensitivity of 74% (20/27), specificity of 91% (104/114), positive predictive value of 67% (20/30), negative predictive value of 94% (104/111), positive likelihood ratio of 8.4 (95% CI 4.5-15.9), and negative likelihood ratio of 0.3 (95%CI 0.2-0.5)], and microbial-associated intra-amniotic inflammation (sensitivity of 100% (17/17), specificity of 90% (111/124), positive predictive value of 57% (17/30), negative predictive value of 100% (111/111), positive likelihood ratio of 9.5 (95% CI 5.7-16.0), and negative likelihood ratio of 0]. CONCLUSION: The point-of-care assessment of interleukin-6 in vaginal fluid is an easy, rapid, non-invasive, and inexpensive method for the identification of intra-amniotic inflammation and microbial-associated intra-amniotic inflammation in preterm PROM pregnancies, showing good specificity and negative predictive value.

Vaginal fluid interleukin-6 concentrations as a point-of-care test is of value in women with preterm prelabor rupture of membranes.

BACKGROUND: Preterm prelabor rupture of membranes is frequently complicated/accompanied by infection and inflammation in the amniotic cavity. A point-of-care determination of amniotic fluid interleukin-6 has been shown to be a potentially clinically useful approach to assess inflammatory status of the amniotic cavity. Amniocentesis in preterm prelabor rupture of membranes is not broadly used in clinical practice, and therefore, a shift toward a noninvasive amniotic fluid sampling method is needed. OBJECTIVE: The first aim of this study was to evaluate the association between the point-of-care vaginal and amniotic fluid interleukin-6 concentrations in fresh unprocessed samples obtained simultaneously. The second goal was to determine the diagnostic indices and predictive value of the point-of-care assessment of vaginal fluid interleukin-6 concentration in the identification of microbial invasion of the amniotic cavity, intraamniotic inflammation, and microbial-associated intraamniotic inflammation in patients with preterm prelabor rupture of membranes. STUDY DESIGN: A prospective cohort study was conducted in women with singleton gestation complicated by preterm prelabor rupture of membranes at between 24+0 and 36+6 weeks. A total of 153 women with singleton pregnancies were included in this study. Vaginal fluid was obtained from the posterior vaginal fornix by aspiration with a sterile urine sample tube with a suction tip. Amniotic fluid was obtained by transabdominal amniocentesis. Interleukin-6 concentrations were assessed with a lateral flow immunoassay in both fluids immediately after sampling. Microbial invasion of the amniotic cavity was determined based on a positive polymerase chain reaction analysis. Intraamniotic inflammation was defined as an amniotic fluid point-of-care interleukin-6 concentration ≥745 pg/mL. RESULTS: Several results were obtained in this study. First, it was possible to perform the point-of-care assessment of interleukin-6 in vaginal fluid in 92% of the women (141 of 153), and only those women were included in the analyses. Second, the rate of microbial invasion of the amniotic cavity and intraamniotic inflammation was 26% (36 of 141) and 19% (27 of 141), respectively. Microbial-associated intraamniotic inflammation was identified in 12% of the women (17 of 141). Third, a strong positive correlation was found between the interleukin-6 concentrations in vaginal and amniotic fluids (Spearman rho 0.68; P < .0001). Fourth, the presence of microbial invasion of the amniotic cavity, intraamniotic inflammation, or microbial-associated intraamniotic inflammation was associated with higher vaginal fluid interleukin-6 concentrations in both crude and adjusted analyses. Fifth, a vaginal fluid interleukin-6 concentration of 2500 pg/mL was determined to be the best cutoff value for the identification of microbial invasion of the amniotic cavity (sensitivity of 53% [19 of 36], specificity of 89% [93 of 104], positive predictive value of 63% [19 of 30], negative predictive value of 85% [93 of 110], positive likelihood ratio of 5.0 [95% confidence interval, 2.5-9.5], and negative likelihood ratio of 0.5 [95% confidence interval, 0.4-0.8]); intraamniotic inflammation (sensitivity of 74% [20/27], specificity of 91% [104/114], positive predictive value of 67% [20 of 30], negative predictive value of 94% [104 of 111], positive likelihood ratio of 8.4 [95% confidence interval, 4.5-15.9], and negative likelihood ratio of 0.3 [95% confidence interval, 0.2-0.5]); and microbial-associated intraamniotic inflammation (sensitivity of 100% [17 of 17], specificity of 90% [111 of 124), positive predictive value of 57% [17 of 30], negative predictive value of 100% [111 of 111], positive likelihood ratio of 9.5 [95% confidence interval, 5.7-16.0], and negative likelihood ratio of 0). CONCLUSION: The point-of-care assessment of interleukin-6 in vaginal fluid is an easy, rapid, noninvasive, and inexpensive method for the identification of intraamniotic inflammation and microbial-associated intraamniotic inflammation in preterm prelabor rupture of membranes pregnancies, showing good specificity and negative predictive value.

Amniotic fluid prostaglandin E2 in pregnancies complicated by preterm prelabor rupture of the membranes.

OBJECTIVE: To determine amniotic fluid prostaglandin E2 concentrations in women preterm prelabor rupture of the membranes (PPROM) with respect to microbial invasion of the amniotic cavity (MIAC), intraamniotic inflammation (IAI), microbial-associated IAI, histological chorioamnionitis, and short-term neonatal morbidity. METHODS: One hundred forty-five women with singleton pregnancies were included in this study. Amniotic fluid samples were obtained by transabdominal amniocentesis and were assayed for prostaglandin E2 concentrations by ELISA. IAI was defined as amniotic fluid interleukin-6 >745 pg/mL. Microbial-associated IAI was defined as the presence of both MIAC and IAI. RESULT: No differences in prostaglandin E2 concentrations were found between women with and without MIAC (p = 0.27). Women with IAI (p = 0.0008) and microbial-associated IAI (p = 0.01) had higher prostaglandin E2 concentrations than women without these complications. Women with histological chorioamnionitis had higher prostaglandin E2 concentrations only in crude analysis (p = 0.02), but not after adjustment for gestational age at sampling (p = 0.10). No associations between amniotic fluid prostaglandin E2 concentrations and the selected conditions of severe neonatal morbidity were found. CONCLUSIONS: The intraamniotic inflammatory response either to infectious or to non-infectious stimulus, but not MIAC per se, seems to be a main factor associated with the elevation of the amniotic fluid PGE2 concentrations in women with PPROM.