Antibiotics and preterm labor

In summary, a definite association has been demonstrated between preterm labor and genital tract infection. Conclusions regarding the true benefits of antibiotics as adjunctive therapy in treatment of preterm labor are inconsistent. Whereas some of the studies were able to demonstrate significant prolongation of pregnancy, no consistent reduction in either maternal or neonatal morbidity has been demonstrated. However, because the actual incidental morbidity rate is low in the populations studied, the power of this finding is also low. The potential risks for using antimicrobials has yet to be adequately addressed. It has been shown that bacterial resistance can develop when antibiotics are used without specific aim or when a specific bacteria is undertreated. It has been recently shown that prenatal and intrapartum antibiotic use is associated with an increased risk for antibiotic resistant neonatal sepsis if infection occurs. Because of these reasons, we discourage the administration of antibiotic treatment to women in preterm labor for the purpose of pregnancy prolongations. Treatment should be directed towards those with specific indications for treatment (e.g., intrapartum, group B streptococci prophylaxis, urinary tract infection, etc). The primary flaw in these many evaluations of preterm labor is the true incidence of preterm birth. The clinical diagnosis of preterm labor is a difficult one. Approximately one-half of those individuals with preterm contractions will not deliver until term. So, the use of antibiotics for all women in idiopathic preterm labor is destined to treat many women who are unlikely to benefit. If we were able to truly identify those who were in "true" labor, perhaps we could be more selective in determining who may benefit from antibiotics. Biochemical markers such as onco-fetal fibronectin could well-be a helpful marker. Goldberg et al evaluated FFN in vaginal and cervical secretions while attempting to better-predict who would have upper genital tract infection. In this large, multicenter trial, patients were tested for FFN every 2 weeks from 23 to 30 weeks gestation. In those patients who proceeded to deliver before 32 weeks gestation, increased levels of cervical FFN (> 50 ng/ml) were identified in approximately one-quarter. Fetal fibronectin was positive in 4% of their samples and was found to be twice as likely in one with bacterial vaginosis. They showed that the presence of increased FFN was associated with upper genital tract infection (clinical and histologic chorioamnionitis) as a main reason for preterm labor and delivery (increased risk 16-20-fold). Those with increased FFN levels were also shown to have an increased incidence of neonatal sepsis as well. Peaceman et al used FFN to attempt to identify those at risk for preterm delivery among women with contractions between 24 and 34 6/7 weeks gestation. Those with negative FFN were less likely to deliver within 7 days of the test. The negative predictive value was 99.7%, suggesting that this test may be helpful in identifying women who would not benefit from antibiotic treatment. However, if in the absence of prospective clinical trials demonstrating the efficacy of this approach, we discourage the use of FFN screening for this indication.     

Cervicovaginal fetal fibronectin (FFN) for prediction of preterm delivery in symptomatic cases: a prospective study

OBJECTIVE: To assess the clinical value of cervicovaginal fetal fibronectin (FFN) in the prediction of preterm delivery (PTD) in women with signs and symptoms of preterm labor (PTL). METHOD: This investigation prospectively studied a cohort of a women with symptoms of PTL, between 24 and 37 weeks' gestation with < 3 cm of cervical dilatation and intact membranes. Cases were evaluated in terms of maternal demographic characteristics like age, body mass index, number of parities, previous PTL history, Bishop scores at admission, gestational age at delivery, mode of delivery, use of tocolytic or steroids, presence of histologic chorioamnionitis, neonatal outcomes and delivery before 34 weeks' gestation as well as within seven days of admission. RESULTS: A total number of 68 cases were included in the study. There were no statistically significant differences between positive and negative FFN groups in terms of maternal characteristics, mode of delivery and adverse neonatal outcomes. However, FFN + cases had higher Bishop scores on admission (3.4 +/- 1.2 vs 2.5 +/- 0.3, p = 0.03) and lower gestational age at delivery (33.4 +/- 3.1 weeks vs 36.8 +/- 2.1 weeks, p = 0.002). Likelihood ratio (LR) for positive results was 1.83 (95% CI: 1.61-2.26) for predicting birth before 34 weeks' gestation, with a corresponding negative LR of 0.62 (95% CI: 0.3-1.2). LR for positive results was 4.34 (95% CI: 3.65-5.12) for predicting birth within seven days of testing, with a corresponding negative LR of 0.3 (95% CI: 0.2-0.5). CONCLUSION: Based on the results of cervicovaginal FFN, positive tests represent an increased likelihood of PTD among women with symptoms of threatened preterm labor.     

Cervical assessment in women with threatened preterm labor.

OBJECTIVE: The aim of the study was to examine the clinical value of cervical assessment by transvaginal ultrasonography in women with symptoms of preterm labor. METHODS: We prospectively evaluated 172 women with singleton pregnancies and symptoms of preterm labor. Seventy of them were nulliparas, while 102 were multiparas. Gestational age ranged between 24 and 34 wks. All women underwent cervical assessment with transvaginal ultrasonography and were given intravenous tocolytics. The only parameter evaluated was cervical length. Women with multiple pregnancies, gestational age <24 wks or >34 wks, cervical dilatation >2 cm, placenta praevia, premature rupture of membranes, or cervical cerclage were excluded from the study. The outcome measure was delivery before 34 wks gestation. RESULTS: The preterm delivery rate before 34 wks was 37%. The sensitivity and the specificity of a cervical length of less than 20 mm was 60 and 53.8% and 97.7 and 95.2% for nulliparas and multiparas, respectively. A cervical length <20 mm was also 93.7% predictive of preterm delivery in nulliparas and 87.5% in multiparas, while the corresponding numbers for its negative predictive value (NPV) were 81.4 and 76.9%, respectively. CONCLUSIONS: Cervical assessment in women with symptoms of preterm labor can distinguish those at high risk for preterm delivery. Cervical sonography can be a valuable adjunct to the clinical evaluation of these patients.     

Cervical assessment in women with threatened preterm labor

Objective.?The aim of the study was to examine the clinical value of cervical assessment by transvaginal ultrasonography in women with symptoms of preterm labor.

Methods.?We prospectively evaluated 172 women with singleton pregnancies and symptoms of preterm labor. Seventy of them were nulliparas, while 102 were multiparas. Gestational age ranged between 24 and 34 wks. All women underwent cervical assessment with transvaginal ultrasonography and were given intravenous tocolytics. The only parameter evaluated was cervical length. Women with multiple pregnancies, gestational age <?24 wks or >?34 wks, cervical dilatation >?2?cm, placenta praevia, premature rupture of membranes, or cervical cerclage were excluded from the study. The outcome measure was delivery before 34 wks gestation.

Results.?The preterm delivery rate before 34 wks was 37%. The sensitivity and the specificity of a cervical length of less than 20?mm was 60 and 53.8% and 97.7 and 95.2% for nulliparas and multiparas, respectively. A cervical length <?20?mm was also 93.7% predictive of preterm delivery in nulliparas and 87.5% in multiparas, while the corresponding numbers for its negative predictive value (NPV) were 81.4 and 76.9%, respectively.

Conclusions.?Cervical assessment in women with symptoms of preterm labor can distinguish those at high risk for preterm delivery. Cervical sonography can be a valuable adjunct to the clinical evaluation of these patients.     

宫颈分泌物中性粒细胞弹性蛋白酶预测早产临床研究

目的:探讨宫颈分泌物中性粒细胞弹性蛋白酶(NE)预测早产的临床价值。方法:选择2008年1月～2009年4月在我院住院保胎并分娩的孕28～36周单胎妊娠符合条件的78例为研究对象。检测宫颈分泌物NE水平,同时观察宫颈分泌物中性粒细胞百分率,比较不同保胎时间,不同分娩孕周,不同孕周胎膜早破(PPROM)NE水平及中性粒细胞百分率,并分析NE水平与中性粒细胞百分率的相关性。结果:保胎时间<7天宫颈分泌物NE水平及中性粒细胞百分率明显高于保胎时间7～14天和>14天(P<0.01);分娩孕周<32周宫颈分泌物NE水平和中性粒细胞百分率明显高于分娩孕周≥32周(P<0.01,P<0.05);孕周<32周发生PPROM明显高于孕周≥32周(P<0.01);孕周<32周的PPROM宫颈分泌物NE水平和中性粒细胞百分率明显高于孕周≥32周的PPROM(P<0.01);保胎时间<7天、分娩孕周<32周和≥32周及孕周<32周的PPROM宫颈分泌物NE水平与中性粒细胞百分率均呈正相关(P<0.05)。结论:保胎时间<7天、分娩孕周<32周以及孕周<32周的PPROM宫颈分泌物NE水平明显升高,宫颈分泌物NE可能成为早产预测指标,尤其对较早期的早产更有意义。     

What we have learned from an antibiotic trial in fetal fibronectin positive women

Clinically silent upper genital tract microbial infections have been strongly associated with spontaneous preterm delivery, especially prior to 32 weeks gestational age. This condition represents a potentially preventable or reversible cause of preterm birth using safe, readily available, and inexpensive antibiotics. Fetal fibronectin detected in cervical and vaginal secretions between 22 to 24 weeks' gestation is a powerful predictor of subsequent risk for spontaneous preterm delivery. Evidence indicates that the detection of fetal fibronectin in cervical/vaginal secretions could represent a marker for clinically silent upper genital tract microbial infection. Thus, the National Institute of Child Health and Human Development Maternal-Fetal Medicine Units (NICHD MFMU) Network performed a randomized clinical trial to determine if antibiotic treatment (metronidazole plus erythromycin) of asymptomatic women with a positive cervical or vaginal fetal fibronectin test in early pregnancy will reduce the risk of spontaneous preterm delivery. No significant difference was observed between the antibiotic- and placebo-treated groups for spontaneous preterm delivery before 37 week's gestation (relative risk 1.17, 95% confidence interval 0.80-1.70). Therefore, use of the fetal fibronectin test to identify women for antibiotic treatment in an effort to prevent preterm birth should be discouraged, and current clinical use of the fetal fibronectin test should be limited to its negative predictive value.     

Interleukin-8 and glucose in amniotic fluid, fetal fibronectin in vaginal secretions and preterm labor index based on clinical variables are optimal predictive markers for preterm delivery in patients with intact membranes

AIM: Various predictive markers for preterm delivery have been proposed in previous studies. We investigated which marker is most reliable. METHODS: In 126 patients with preterm labor before 32 weeks of gestation and intact membranes, who had regular uterine contractions with cervical changes effaced > or =50%, we evaluated seven markers: interleukin (IL)-8, glucose, and granulocyte count in amniotic fluid (AF); fetal fibronectin (fFN) in vaginal secretions; IL-8 in cervical mucus; cervical length; and preterm labor index (PLI) based on clinical variables. The relationships of these variables to the occurrence of preterm delivery before 34 weeks were examined by logistic regression analysis. RESULTS: Values for AF IL-8, AF granulocyte count, fFN in vaginal secretions, and PLI were significantly higher, while the value for AF glucose was significantly lower, in patients delivering before 34 weeks than those in patients delivering at or following 34 weeks (P < 0.0001 for all). The most sensitive marker for predicting delivery before 34 weeks was AF IL-8 (sensitivity, 67.8%). The most specific markers were AF IL-8 (specificity, 95.5%) and PLI (specificity, 95.5%). By the logistic regression analysis, AF IL-8, AF glucose, fFN in vaginal secretions and PLI showed independent relationships with delivery before 34 weeks (P = 0.0009, P = 0.0032, P = 0.0131 and P = 0.0038, respectively). CONCLUSIONS: In preterm labor with intact membranes, AF IL-8, AF glucose, fFN in vaginal secretions and PLI were highly predictive markers for detecting preterm delivery before 34 weeks.     

Increased level of granulocyte elastase in cervical secretion is an independent predictive factor for preterm delivery

OBJECTIVE: The objective of this study was to explore whether increased levels of granulocyte elastase in cervical secretion is an independent predictive factor for preterm delivery before 34 weeks of gestation in the patient with preterm labor. METHODS: One hundred and sixty-one women with preterm labor at 22-28 weeks of gestation were enrolled prospectively. The level of granulocyte elastase in cervical secretions was measured by immunoassay, vaginal secretions were collected for the microscopic evaluation of Gram-stained smears, and the uterine cervix was assessed by transvaginal ultrasonography. RESULTS: Nineteen of 161 patients (12%) delivered before 34 weeks of gestation. Granulocyte elastase assessment had a sensitivity, specificity, positive predictive value, and negative predictive value for preterm delivery of 53, 75, 22 and 92%, respectively. A positive elastase assessment was associated with a relative risk for preterm delivery of 2.9 (95% CI 1.3-6.6), whereas a positive bacterial vaginosis assessment and shorter cervical length less than 25 mm demonstrated a relative risk of 1.9 (95% CI 0.8-4.6) and 1.5 (95% CI 0.6-5.0), respectively. CONCLUSION: The present study demonstrates that the risk of spontaneous preterm delivery before 34 weeks of gestation is increased in the women with preterm labor who are found to have an increased level of granulocyte elastase in cervical secretions.     

Performance of cervicovaginal fetal fibronectin in a community hospital setting

Objective To assess the accuracy of vaginal fetal fibronectin (FFN) as a screening test for preterm delivery in a community hospital. Study design A prospective cohort of patients at high risk for preterm delivery at a community hospital underwent testing with FFN over a 15 month-period (March 2004–May 2005). Indications for testing were preterm labor, multiple pregnancies, cervical shortening, and cerclage. Pregnancy characteristics were retrieved on all women with positive FFN results and controls in a 1:2 ratio. Outcome variables included interval to delivery; length of hospital stay; and rates of preterm delivery <37 weeks. In the presence of serial FFN testing, only the initial result was used for calculation of diagnostic indices. Statistical analysis utilized t-test, Fisher’s exact test and logistic regression analyis to control for gestational age at testing, with P < 0.05 or odds ratio (OR) with 95% confidence interval (CI) not inclusive of the unity considered significant. Results Two hundred and fifty seven FFN tests were performed in 230 women, of which 33 (14.3%) had positive FFN results. Duration of hospital stay was significantly shorter for patients with negative than positive results (8 h vs. 2.1 days, P = 0.011). Women with positive FFN were more likely to deliver within 14 days (OR = 6.5, 95% CI 1.4; 30.7), within 21 days (OR = 4.8; 95% CI 1.4; 16.6), before 34 weeks (OR = 5.0, 95% CI 1.7; 14.8) and before 37 weeks (OR = 3.1; 95% CI 1.3; 7.1) than women with negative results. Conclusion A negative FFN result provides enough reassurance to allow shorter hospital stay. In a real-world setting (a community hospital with a population heterogenous for risk factors for preterm delivery, and in a non-protocol setting) the performance of FFN testing closely mirrors that obtained in academic institutions, where the test was studied in more uniform populations under strict protocols. Summary The performance of vaginal fibronectin in patients with heterogeneous risk factors for preterm delivery closely mirrors that obtained in studies conducted in populations with homogeneous risk factors.     

Effectiveness of fetal fibronectin testing compared with digital cervical assessment of women with preterm contractions

The purpose of this study is to determine the effectiveness of fetal fibronectin (FFN) compared to assessment of cervical dilation (CD) in clinical management of women with symptomatic preterm labor (PTL). Pregnant women presenting to Thomas Jefferson University Hospital between May 1, 2001 and November 30, 2002 with symptomatic PTL underwent FFN sampling and had a complete clinical evaluation including a pelvic bimanual examination. Inclusion criteria were singleton pregnancy, gestational age (GA) between 24 (0) and 33 (6) weeks, CD < 3 cm, and intact amniotic membranes. FFN samples were sent out and results were available within 4-12 hours. Clinical management including tocolysis, antenatal steroids, and hospitalization was determined based on digital CD assessment and FFN status. A dilated cervix was defined as CD > 1 cm. Ninety-three patients were included. Spontaneous preterm delivery (SPTD) at < 37 weeks occurred in 20 of 93 (21.5%) patients. Medical therapy use was significantly higher in patients with dilated cervix than in those with a closed cervix (all P values < 0.05). Tocolysis and steroid use in FFN-negative patients and FFN-positive patients were not significantly different. Furthermore, tocolytic use was higher in FFN-negative patients than in women with positive FFN (50% versus 42.1%; P = 0.53). Use of antenatal steroids was similar in patients with CD >/= 1 cm and a positive FFN (54.5% versus 47.4%; P = 0.92). Compared with FFN-negative patients, women with closed cervix were less likely to undergo interventions. In symptomatic PTL patients, CD determined clinical management more than FFN status. Overall, the use of FFN was not effective in decreasing "unnecessary" clinical interventions.     

Secondary predictors of preterm labour

In addition to primary predictors of preterm birth which are used to estimate the baseline risk of preterm birth, secondary predictors (based on examinations done during the current pregnancy) allow a more accurate assessment of the risk of preterm birth in individual women. Screening for early signs of spontaneous preterm labour has always been an important topic in obstetric care. During the last two decades, the detection of fetal fibronectin (FFN) from cervicovaginal secretions and cervical shortening diagnosed by transvaginal ultrasonography have emerged as the major secondary predictors of preterm birth. Both markers have been extensively studied and consistently shown to be strong short term predictors of preterm birth across a wide range of gestational ages. Other secondary predictors that confirm the role of intrauterine infection in the pathogenesis of preterm birth are bacterial vaginosis (BV) and elevated levels of interleukin (IL)-6, IL-8, ferritin and granulocyte colony-stimulating factor. Apart from BV, inflammatory markers are still not routinely used. The sensitivity of single markers in predicting preterm birth is only moderate and serial examinations of markers, combinations of different markers and multiple marker tests have been studied, with limited results. Studies of interventions in order to prevent preterm birth have also yielded mixed benefits, as a consequence of which the use of these markers to screen low risk pregnancies is generally not recommended. Currently, secondary predictors of preterm birth are used mainly to design new intervention studies tailored to specific high risk populations and to avoid unnecessary interventions in the management of high risk women.     

Human chorionic gonadotropin in cervicovaginal secretions as a predictor of preterm delivery.

OBJECTIVES: To determine whether human chorionic gonadotropin (hCG) detected in cervicovaginal secretions of patients with symptoms suggestive of preterm labor is a predictor of preterm birth. METHODS: Women presenting to labor and delivery with symptoms of preterm labor were invited to participate. After collecting secretions with a cotton-tipped applicator from the posterior fornix and endocervical canal, we placed the swab in a test tube containing 1 ml of normal saline. From this solution, we performed qualitative and quantitative hCG measurements. Qualitative and quantitative hCG results from women who delivered at term were compared with those delivering prior to 37 weeks' gestation. RESULTS: Samples were obtained and analyzed from 86 women at a mean (+/- standard deviation) gestational age of 30.7+/-2.9 weeks. Of the 86 subjects enrolled, 28 (32.6%) delivered preterm. A positive rapid qualitative assay from cervicovaginal secretions between 24 and 34 weeks' gestation was associated with a significant increase in the incidence of preterm delivery (relative risk 2.62, 95% confidence interval (CI) 1.38, 4.98). The likelihood ratios for a positive and negative test were 2.19 (95% CI 1.35, 3.56) and 0.51 (95% CI 0.30, 0.85) respectively. Using a cut-off of 19 mIU/ml, similar diagnostic accuracy for predicting preterm birth was obtained with the quantitative test 1.93 (95% CI 1.14, 3.26) and 0.62 (95% CI 0.40, 0.98). CONCLUSIONS: Qualitative and quantitative hCG measurements from cervicovaginal secretions may be useful predictors of preterm birth in symptomatic patients. The qualitative hCG test can be used at the bedside with results obtained in minutes.     

Fetal fibronectin as predictor of successful induction of mid-trimester abortion

BACKGROUND: Fetal fibronectin (FFN) in cervical secretion is one of the most effective markers of pre-term and term delivery. The presence of FFN in cervicovaginal secretions has recently been shown to reflect cervical state and an uncomplicated induction of labor at term. This study was designed to determine whether FFN could be a biochemical marker to predict the response to prostaglandins in early mid-trimester abortion. METHODS: The presence of cervical FFN was evaluated by means of qualitative rapid immunoassay in 270 patients, who required second trimester termination of pregnancy at the Department of Gynecology and Obstetrics, University of Naples 'Federico II'. According to the standard protocol of our unit, women received 1.0 mg of gemeprost intravaginally at 3-hr intervals up to a maximum of five suppositories. The induction-to-abortion interval and the percentage of successful abortions within 24 hr in women in the positive FFN group (n=19) were compared with those in the negative FFN group (n=251). RESULTS: FFN in the cervical secretions was present in seven women (10.2%) at 16-weeks gestation, in seven women (7.5%) at 17-weeks gestation, and in five women (4.5%) at 18-week gestation. Final termination rates were 13 (68.4%) in the fibronectin-positive group and 177 (70.5%) in the fibronectin-negative group. The median abortion interval was similar (14.7 versus 15.1 hr) in both groups. CONCLUSIONS: A positive cervical fetal fibronectin test does not predict a successful medical termination of pregnancy in second trimester abortion. In this setting, the role of fetal cervical fibronectin in cervical ripening is, therefore, questionable.     

Ultrasonographic measurement of cervical length in twin pregnancies with preterm labor: comparison with singleton pregnancies

OBJECTIVE: Our purpose was to assess the utility of ultrasonographic measurement of cervical length for predicting preterm delivery in pregnant women with twin pregnancy and preterm labor. PATIENTS AND METHOD: Prospective study in 192 singleton and 66 twin pregnancies with preterm labor before 34 weeks. Vaginal sonography for measurement of cervical length, and screening for fetal fibronectin in vaginal smears were performed at admission. The incidence of delivery before 34 weeks was compared with cervical length and the presence of fetal fibronectin. RESULTS: In singleton pregnancies, delivery before 34 weeks was significantly more frequent in women with a cervical length <30 mm (26.6 vs. 2.0%; P = 0.0004), or presence of fetal fibronectin (27.5 vs. 6.0%; P = 0.001). The corresponding negative predictive values (NPV) were 98% and 94%, respectively. In twin pregnancies, receiver characteristic curve analysis showed that a cervical length of 20 mm had the highest diagnostic performance in predicting preterm delivery. The corresponding NPV was 63%. In this group, delivery before 34 weeks showed no significant difference in women with a cervical length < 30 mm (43.7 vs. 38.8%), cervical length < 20 mm (52.0 vs. 36.6%, P = 0.219), or presence of fetal fibronectin (47.6 vs. 21.7%, P = 0.0705). DISCUSSION AND CONCLUSION: Ultrasonographic measurement of cervical length does not predict preterm delivery in twin pregnancies with preterm labor.     

Predictors of preterm birth.

OBJECTIVE: This is a systematic review to assess published scientific evidence on preterm birth predictors. METHODS: An Internet search for predictors of preterm birth was performed and the evidence level of each method was evaluated. RESULTS: There is strong evidence that preterm birth can be predicted using vaginal sonography to evaluate cervical characteristics, fetal fibronectin in cervicovaginal secretions and interleukin-6 in amniotic fluid. There is consistent evidence that digital cervical examination is a weak predictor, and controversy regarding home uterine activity monitoring. There is scanty evidence about the predictive ability of maternal history and perceptions of symptoms since the study design fails to provide high evidence level. CONCLUSION: Cervical evaluation by vaginal sonography, fetal fibronectin and interleukin-6 are the best methods for predicting preterm birth.     

Controversies in diagnosis of preterm labour

Despite scientific advances, efforts to prevent preterm birth can be disappointing. Obstetric care must focus on strategies to improve the outcome of preterm infants. The major goal is to delay preterm birth long enough to allow the transfer of women about to deliver preterm to a facility with a neonatal intensive care unit and to administer corticosteroids to enhance fetal lung maturation. A prerequisite for the success of this strategy is the reliable identification of women who will give birth preterm. Although symptoms of preterm labour strongly suggest preterm birth, contractions—even if combined with cervical effacement and dilation—do not reliably predict preterm birth. The diagnosis of true preterm labour that will eventually lead to preterm birth has been facilitated by the use of transvaginal cervical ultrasonography and by the detection of fetal fibronectin (FFN) in cervicovaginal secretions. The main clinical value of these tests is that preterm birth is very unlikely if the results of both tests are negative. This may help to avoid unnecessary transfer, hospitalisation and treatment of women with false preterm labour. The detection of phosphorylated insulin-like growth factor binding protein-1 in cervicovaginal secretions, or elevated levels of inflammatory markers, like interleukin-6, interleukin-8 and tumour necrosis factor-α (TNF-α), also predict preterm birth in symptomatic women. These markers, however, are not routinely used to predict preterm birth in women with symptoms of preterm labour.     

The value of interleukin-8, interleukin-6 and interleukin-1beta in vaginal wash as predictors of preterm delivery

AIMS: To study the value of interleukin (IL)-8, IL-6 and IL-1beta in vaginal wash as predictors of preterm delivery. METHODS: A prospective analysis of a study group of 200 pregnant women between 24 and 34 weeks of gestation with intact membranes and preterm labor and a control group of 50 pregnant women during the same period of gestation. The controls had uncomplicated pregnancies and subsequently delivered at term. Samples of vaginal secretions were collected from both groups and analyzed for IL-1beta, IL-6 and IL-8 concentrations. RESULTS: Of the women in the study group, 70 had preterm deliveries, while all women in the control group had full-term deliveries. Compared with the control group, the study group had significantly higher concentrations (p < 0.021) of IL-1beta, IL-6 and IL-8. The women in the study group delivering preterm also had IL-1beta, IL-6 and IL-8 concentrations significantly greater (p < 0.001) than those of the same group delivering full term. ROC curves were used to establish cut-off points for the three interleukins to predict preterm delivery. We did not find a cut-off point with an appropriate sensitivity and specificity. CONCLUSION: The concentrations of interleukins in vaginal wash were significantly higher both in the women with preterm labor and in those delivering preterm. While values differed between controls and those with the preterm labor, no cut-off can be obtained to use the results of IL-1beta, IL-6 and IL-8 as a predictor clinically.     

Failure of cervical fibronectin to predict premature delivery in a population of monofetal pregnancies with idiopathic preterm labor.

OBJECTIVE: The purpose of the study was to evaluate the correlation between the presence of cervical fibronectin in a high-risk population of women with symptoms of preterm labor and the occurrence of preterm delivery or the need for aggressive tocolysis. STUDY DESIGN: One hundred and thirty women presenting with symptoms of threatened preterm labor were included. Cervical sampling for detection of fibronectin was performed on admission and every day until discharge or delivery. Time to delivery, length of hospital stay, use of indomethacin, delivery before 37 weeks of GA, mean term of delivery and failure of tocolysis to prevent delivery were compared to fibronectin test results. Data were analyzed using Student's t-test for continuous variables and the chi(2) test or Fisher exact test for discrete variables. RESULTS: No correlation could be found between the results of fibronectin cervical sampling on admission and any of the outcome parameters studied. Test performances were low (sensitivity 28%, specificity 57%, positive predictive value 19%, negative predictive value 69%). Results were not modified when the findings of repeated tests were taken into account. CONCLUSION: Cervical fibronectin failed to discriminate a subgroup of symptomatic women delivering prematurely. The prognostic value of fibronectin testing was not better than clinical data in our series. This observation is in disagreement with previous studies on the diagnostic value of vaginal or cervical fibronectin in preterm labor.     

Comparison of biochemical markers and cervical length for predicting preterm delivery

AIM: To examine the clinical utility of several prognostic factors for predicting preterm delivery. METHODS: One hundred and nineteen patients with a singleton pregnancy admitted to our hospital because of symptoms of preterm labor were included in this study. Maternal serum C-reactive protein (CRP), transvaginal sonographic measurement of cervical length (CL), granulocyte elastase (EL) in cervical secretions, fetal fibronectin (fFN), alpha-fetoprotein (AFP), and insulin-like growth factor binding protein-1 (IGFBP-1) in vaginal secretions were examined on admission. EL, fFN, AFP, and IGFBP-1 were measured by bed-side test kits. Correlation between each factor and the duration of pregnancy (from admission to delivery) was investigated. RESULTS: A significant correlation was found between the duration of pregnancy and CRP (r= -0.37, P<0.001), but not CL. The duration was significantly shorter in the fFN-positive group than in the negative group (P=0.0015). However, no significant difference was observed between the positive group and the negative group for each of CL, EL, AFP and IGFBP-1. CONCLUSION: Association between the duration of the pregnancy and two biochemical markers (CRP and fFN) was confirmed. As they can be examined quickly and easily, they are quite useful for estimating prognosis of preterm labor.     

Fetal fibronectin as a predictor of term labor: a literature review

OBJECTIVE: Accurately predicting the onset of delivery continues to be problematic notwithstanding the clinical relevance of this capability, especially with regard to the elective induction of labor. While the assessment of the cervix according to Bishop, to date, constitutes the single generally recognized method, the determination of fetal fibronectin (FFN) cervicovaginal secretions promises greater precision in this context. DESIGN: English-language medical literature was analyzed using the search parameter 'fetal fibronectin', 'term delivery', 'induction of labor', 'labor', and 'birth', respectively. All those original reports examining cervicovaginal FFN that were originally published in English and followed a prospective design were subsequently included in the study at hand. These reports were evaluated in regard to their findings on the predictive value of FFN for spontaneous delivery and induction of labor. RESULTS: A total of eight reports were included in the present study: five of these, covering a total of 480 patients, discussed the relationship between FFN and the spontaneous onset of labor; the other three addressed the subject of FFN and the induction of labor (300 patients). All reports clearly related the presence of FFN in cervicovaginal secretions to the imminent onset of delivery; three studies, furthermore, demonstrated a correlation with the spontaneous onset of labor, with a sensitivity greater than 90%. In case of the studies concerning induction of labor, a positive FFN result was accompanied by a significantly shorter interval until delivery than a negative FFN result. CONCLUSION: Determining the presence of FFN in cervicovaginal secretions promises to provide an indicator relating to the prediction of term labor, as well as to the prediction of successful labor induction.