Fetal fibronectin: A new tool for the prediction of successful induction of labor

OBJECTIVE: The Bishop score is the only available tool for predicting successful labor induction. Vaginal fetal fibronectin has been shown to predict which patients will enter labor spontaneously, usually within 2 weeks. This study was designed to determine whether fetal fibronectin can also predict the success of labor induction. STUDY DESIGN: Term patients undergoing labor induction had a single swab from the vagina tested for fetal fibronectin before initiation of cervical ripening or oxytocin. The swab was tested with a blinded qualitative immunoassay for fetal fibronectin (positive ≥50 ng/ml). RESULTS: Of the overall 160 subjects, 108 had a positive and 52 had a negative fetal fibronectin result. Patients with a positive result had a lower cesarean section rate (15% vs 27%, p = 0.05) and shorter intervals to delivery, including first dose of prostaglandin to delivery interval (21.3 vs 35.8 hours, p = 0.0001) and first stage of labor (14.8 vs 21.2 hours, p = 0.0009). These differences remain similar even in nulliparous women with Bishop scores ≤5, with patients with positive results having statistically shorter intervals to delivery and similar differences in cesarean section rates (22% vs 35%), although this difference was not significant. In this subgroup more than half the patients in the negative results group (11/20) were undelivered after 24 hours and were judged to require a second dose of prostaglandin compared with only 2 of 53 in the group with positive results (p = 0.000001). By stepwise logistic regression analysis the predictive ability of a positive result for fetal fibronectin was found to be independent of the Bishop score. CONCLUSIONS: Vaginal fetal fibronectin appears to be an efficacious new test that independently predicts which patients will have shorter and easier inductions of labor and lower cesarean section rates, even nulliparous patients with low Bishop scores. This test has the potential for clinical utility and cost reduction. (Am J Obstet Gynecol 1996;175:1516-21.)     

Digital and transvaginal ultrasound cervical assessment for prediction of successful labor induction.

OBJECTIVE: To compare the values of preinduction transvaginal cervical length measurements and Bishop score to predict successful labor induction. METHODS: A prospective, observational trial of nulliparous women undergoing labor induction. Inclusion criteria were gestational age between 36 and 42 weeks, singleton cephalic presentation of the fetus, and intact membranes. Preinduction cervical ripening was performed using 25 microg intravaginal misoprostol (PGE1), repeated every 4 h, up to a maximum of 3 doses. Induction was subsequently continued by oxytocin and amniotomy. RESULTS: A total of 43 women met the inclusion criteria. Mean preinduction cervical length for women with successful or failed labor induction was 26 mm (95% Confidence interval [CI], 27-32) and 34 mm (95% CI, 33-38), respectively (P=0.002). Mean Bishop scores for successful and failed induction groups were 5.4 (95% CI, 5.2-6.2) and 3.1 (95% CI, 2.8-3.5), respectively (P=0.003). CONCLUSION: Digital examination and transvaginal ultrasound of the cervix predict successful labor induction with reasonable accuracy.     

Factors associated with the length of the latent phase during labor induction

OBJECTIVE: To evaluate the factors that are associated with the length of the latent phase during labor induction in nulliparous women. STUDY DESIGN: During a 6-month period, all nulliparous women with a viable fetus of at least 36 weeks gestation who underwent induction of labor were identified. Demographic and intrapartum data were abstracted from the medical record. In an effort to understand the association of different factors with the length of the latent phase, both univariable and multivariable analyses were employed. RESULTS: The median length of the latent phase for the women available for analysis (N=397) was 384 min with an interquartile range of 240-604 min. In univariable analysis, a greater maternal age, a medical indication for induction, and unripe cervical status at admission (assessed by either modified Bishop score or use of cervical ripening agents) were significantly associated with a latent phase of at least 12 h. In multivariable analysis, the only variables that continued to be independently associated with a latent phase of at least 12 h were modified Bishop scores of 0-2 (adjusted odds ratio 42.0, 95% confidence interval 9.7, 183.2) and 3-5 (adjusted odds ratio 9.3, 95% confidence interval 2.1, 40.9). CONCLUSION: A woman's modified Bishop score at admission for labor induction, but not other risk factors typically associated with cesarean, is associated with length of the latent phase.     

欣普贝生用于足月胎膜早破低宫颈评分引产的效果观察

目的:探讨欣普贝生(地诺前列酮栓)在足月胎膜早破初产孕妇中应用的安全性及有效性。方法:100例足月胎膜早破单胎孕妇,破膜2h后未临产,宫颈条件未成熟(宫颈Bishop评分≤4分),孕妇知情同意后欣普贝生组入组50例,催产素组50例。比较两组的分娩方式及母儿结局情况。结果:与催产素组比较,欣普贝生组8h、12h促宫颈成熟总有效率明显增加(92.0%vs 64.5%,P0.01;95.9%vs 79.2%,P0.05)。欣普贝生组阴道分娩率明显升高(86.0%vs 60.0%,P0.01),且欣普贝生组用药12h、24h内阴道分娩率亦显著提高(42.0%vs 8.0%,P0.001;64.0%vs 34.0%,P0.01)。欣普贝生组用药至临产、用药至阴道分娩时间明显短于催产素组[(7.4±1.0)h vs(14.2±2.0)h,P0.01;(15.4±1.4)h vs(21.4±1.6)h,P0.01]。欣普贝生组引产失败率、绒毛膜羊膜炎发生率显著降低(2.0%vs 16.0%,P0.05;0 vs 12.0%,P0.05);两组急产、胎儿宫内窘迫、相对性头盆不称发生率无明显统计学差异;两组均无产后出血、新生儿窒息。结论:足月胎膜早破且宫颈条件未成熟的初产孕妇,应用欣普贝生促宫颈成熟安全、有效,且效果优于直接催产素引产,但用药期间应加强母儿监护。     

Bishop score versus ultrasound of the cervix before induction of labor for prolonged pregnancy: which one is better for prediction of Cesarean delivery

Abstract

Objectives: To find an effective way to predict Cesarean section (CS) before induction of labor.

Methods: Nulliparous women at ≥41 weeks of pregnancy were enrolled in the study. Bishop score (BS), cervical length (CL), posterior cervical angle (PCA), quantification of the cervical stromal echogenicity by tissue histograms and opening of the internal cervical os (funnelling) were recorded. The vaginal delivery and CS groups were then compared in terms of the clinical and ultrasonographic cervical findings.

Results: BS, CL, PCA and funnelling were the significant predictors of CS, whereas no such relationship existed for the quantitative echogenicity of the cervical stroma. Although the difference was not statistically significant, the area under the curve was higher for the BS than that for sonographic CL and PCA in the prediction of all CSs. The best cut-off values to predict CS for BS, CL and PCA were <5, >27?mm and <98°, respectively. Combination of all three parameters had a sensitivity of 83.3%, specificity of 100%, positive predictive value of 100% and a negative predictive value of 82% for the prediction of CS.

Conclusions: In nulliparous women with prolonged pregnancy, the BS predicts the need for CS better than the ultrasonographic assessment of the cervix.     

Pre-induction sonographic assessment of the cervix in the prediction of successful induction of labour in nulliparous women

OBJECTIVE: To compare the efficacy of ultrasonographic cervical assessment with Bishop score before induction of labour in predicting the success of labour induction in nulliparous women. METHODS: This is a prospective study conducted in 138 women who underwent cervical assessment with transvaginal sonography followed by digital cervical assessment using Bishop score before induction of labour. Ultrasonographic parameters evaluated were cervical length, posterior cervical angle and funnelling were blinded to the managing physicians. Statistical analysis was carried out using Mann-Whitney test, chi2 test, receiver operating characteristics curves and logistic regression analysis. RESULTS: Induction of labour was successful in 106 (76.8%) of the women. Multiple logistic regression analysis demonstrated cervical length and posterior cervical angle assessed by transvaginal sonography as independent predictors of successful outcome after induction of labour. Neither Bishop score nor its individual parameters were found to be significant in the regression analysis. The area under the receiver operating characteristic curve for cervical length and posterior cervical angle was greater than that of the Bishop score in predicting a successful labour induction. The best cut-off point for the parameters in receiver operating characteristics curve was 3.0 cm for cervical length and 100 degrees for posterior cervical angle. Cervical length of 3.0 cm had a sensitivity of 84.9%, and a specificity of 90.6% and a posterior cervical angle of 100 degrees with 65% and 72%, respectively. CONCLUSIONS: Transvaginal sonographic assessment of cervical length and posterior cervical angle is better than conventional Bishop score in predicting successful labour induction in nulliparous women.     

Comparison of the Bishop score, body mass index and transvaginal cervical length in predicting the success of labor induction

Purpose  To evaluate the role of ultrasonographic and various maternal and fetal parameters in predicting successful labor induction. Methods  Body mass index, cervical length, dilatation, effacement, Bishop score, parity, maternal age and birth weight were evaluated in 189 singleton pregnant women at 37–42 weeks of gestation and having induction of labor. All underwent induction of labor with oxytocin. Body mass index was calculated using the formula weight (kg)/height² (m), cervical measurement was performed by transvaginal ultrasonography and Bishop score was determined by digital examination of cervix. Results  Logistic regression analysis indicated that the cervical length and body mass index were independent variables in determining the risk of cesarean section (OR = 1.206, P = 0.000, CI 95% = 1.117–1.303; OR = 1.223, P = 0.007, CI 95% = 1.058–1.414 respectively). In multiple linear regression analysis, the effect of cervical length and body mass index on induction delivery interval was found to be statistically significant (t = 5.738, P = 0.000; t = 2.680, P = 0.009, respectively). ROC curve showed that the best parameter in predicting the risk of cesarean section was cervical length and that cervical length and body mass index were better parameters compared to the Bishop score (the areas under the curve are 0.819, 0.701 and 0.416, respectively). Conclusions  Body mass index and transvaginal cervical length were better predictors compared to the Bishop score in determining the success of labor induction.     

PGE2 gel for enhancement of priming and induction of labour at term in patients with unfavorable cervix

Fifty women (25 nulliparae and 25 multiparae) with unfavourable cervix at term were enrolled in a clinical experiment to evaluate the safety and efficacy of the intracervical application of 0.5 mg PGE₂ gel for cervical softening and eventual induction of labour; duration of pregnancy (38–42 wk) was confirmed by ultrasonic records. Global analysis revealed 48 (96%) vaginal deliveries, 43 (86%) being spontaneous labour and 5 (10%) instrumentally assisted deliveries (forceps). Caesarean section was required in 2 cases (4%). Three patients, having registered no Bishop score (above 5) progress after the first treatment, went into labour upon the second application of PGE₂ gel. Mean induction-delivery time was 11 h 50 min for nulliparae and 7 h 50 min for multiparae. Mean ROM/amniotomy-delivery time was 5 h 59 min for nulliparae and 3 h 11 min for multiparae. Four neonates with initial Apgar scores below 7 registered immediately higher values after adequate reanimation manouvres.     

Outcome of induction of labour using maternal characteristics,ultrasound assessment and biochemical state of the cervix

Objective.?To assess pre-induction sonographic, digital examination and biochemical changes in the cervix to predict induction outcome.

Methods.?Transvaginal and abdominal scans were performed in 460 women at 37–41 weeks of gestation to determine cervical length (CL), posterior cervical angle (PCA) and foetal occipital position. The Bishop Score (BS) and the absence/presence of phosphorylated form of insulin-like growth factor-binding protein-1 (phIGFBP-1) in cervical secretions were assessed. Independent parameters significantly associated with a vaginal delivery were identified.

Results.?A total of 340 (73.9%) women achieved a vaginal delivery following induction. Multivariate analysis indicated that significant independent predictors of vaginal delivery were CL (adjusted odds ratio [AOR]: 0.59, 95% confidence interval [CI]: 0.45–0.79), PCA (AOR: 1.89, 95% CI: 1.09–3.28) and multiparae (AOR: 10.02, 95% CI: 5.10–19.69). For a specificity of 75%, the sensitivity for prediction of vaginal delivery using the BS, the CL and the multivariate model using the identified significant independent predictors were 37.1, 46.8 and 68%, respectively.

Conclusion.?The combination of sonographic assessment of the cervix and maternal characteristics was superior to the either BS or CL alone in the prediction of the induction outcome. Inclusion of the absence/presence of phIGFBP-1 did not further improve induction outcome.     

Comparison of elective induction of labor with favorable Bishop scores versus expectant management: A randomized clinical trial

Objective.?To determine if elective induction (IND) increases the risk of cesarean delivery compared to expectant management (EM).

Methods.?A randomized clinical trial involving women ?39 weeks' gestation, according to strict dating criteria, with a Bishop score of 5 or more in nulliparous patients and 4 or more in multiparous patients. The control group was expectantly managed and delivered for obstetric indications, but not later than 42 weeks' gestation. The study had 80% power to detect a three-fold increase in cesarean delivery.

Results.?One-hundred-and-sixteen patients (45 nulliparous) were randomized to IND and 110 (58 nulliparous) to EM. Demographic characteristics were no different between the groups. The cesarean delivery rate in the IND group was 6.9% (8/116) compared to 7.3% (8/110) in the EM group (p?=?NS). Rates of cesarean delivery for nulliparous patients randomized to IND compared to EM were also not significantly different: 13.3% (6/45) versus 10.3% (6/58) respectively (p?=?NS). Neonates delivered of IND patients weighed less than those of the EM group (3459?±?347 versus 3604?±?438, p?=?0.006).

Conclusion.?In women with favorable Bishop scores, elective induction of labor resulted in no increase in cesarean delivery compared to expectant management.     

The fast-reacting fetal fibronectin test: A screening method for better prediction of the time of delivery

OBJECTIVE: Our aim was to determine from what time onward fetal fibronectin is consistently detectable in the cervicovaginal secretions before delivery and to what extent the actual time of delivery can be better determined by this procedure than by the sole use of the Bishop score.STUDY DESIGN: A fast-reacting fetal fibronectin test was performed on 206 women on their expected date of confinement. In addition, the cervical status was evaluated with use of a modified Bishop score. Follow-up evaluations were subsequently carried out in the course of the routine examinations.RESULTS: Women with a positive fetal fibronectin test result and a high Bishop score were delivered after a median of 1.7 days. Conversely, women with a negative fetal fibronectin test result and a low Bishop score were delivered after a median of 7.1 days.CONCLUSION: Determination of fetal fibronectin in combination with the Bishop score makes it possible to predict the actual time of delivery with a greater degree of accuracy.(Am J Obstet Gynecol 1997;177:1478-82.)     

妊娠晚期引产指征和成功率的探讨

目的通过回顾性分析妊娠晚期引产和自然临产的临床资料,探讨引产指征的掌握和引产方式对分娩过程和结局的影响。方法将2008年1月1日至4月15日在北京大学第一医院非选择性剖宫产分娩的587例单胎孕足月初产妇作为研究对象,引产组258例,自然临产组329例。比较两组的年龄、体重指数、分娩孕周,总产程时间,分娩方式和剖宫产指征。比较引产组的引产指征及单纯因孕龄超过预产期引产的64例与自然临产组的剖宫产率。比较不同宫颈条件和新生儿体重对分娩方式的影响以及两种促宫颈成熟的方法即缩宫素静脉点滴和阴道内放置普贝生对宫颈条件的改善情况。统计方法：计数资料采用卡方检验和Fisher′s精确概率法,计量资料采用t检验。结果引产组和自然临产组孕妇比较年龄、体重指数、分娩孕周和总产程时间均无统计学差异。引产指征包括妊娠合并症、胎膜早破、孕41周及其他。引产组剖宫产率明显高于自然临产组（48.1%vs17.0%,P〈0.05）。引产组剖宫产指征第一位为引产失败,自然临产组剖宫产指征主要为胎儿窘迫和产程停滞。引产组宫颈评分越低,剖宫产率越高。两种促宫颈成熟的方法比较,采用普贝生对宫颈条件改善程度明显高于缩宫素。结论在临床密切监测下,应严格掌握引产指征,减少引产,降低剖宫产率。勿因当前医疗环境影响而扩大引产范围。对于宫颈条件差的引产患者应首先选择有效的促宫颈成熟剂即前列腺醇制剂改善宫颈条件,可降低引产失败率。     

Vaginal fetal fibronectin evaluation before and immediately after ultrasonographic vaginal cervical length measurements in symptomatic women at risk of preterm birth: A pilot study

Objective.?To determine if vaginal ultrasound for cervical length measurement induces the release of vaginal fetal fibronectin (fFN), leading to a false-positive fFN test.

Methods.?Participants included women with singleton pregnancies at 24–34 weeks' gestation who presented with uterine contractions without bleeding or membrane rupture. Women who had had intercourse or underwent pelvic examination less than 24?h previously were excluded. The first fFN test was followed immediately by vaginal ultrasonography with a transvaginal probe (three images per patient) and, thereafter, a second fFN test.

Results.?The first fFN test was positive in three patients, and in all, the second, post-ultrasound, fFN test was also positive. In all women with a negative baseline fFN test (n?=?25), the second, post-ultrasound, fFN test was also negative.

Conclusion.?Vaginal ultrasound examination does not artificially change the fFN status. This is in contrast to common understanding and may permit the performance of ultrasound examination before fFN, which can be restricted to cases of short cervix.     

Evaluation of quantitative ultrasound tissue characterization of the cervix and cervical length in the prediction of premature delivery for patients with spontaneous preterm labor

OBJECTIVE: This study was to evaluate the predictive value of the uterine cervix tissue with the use of quantitative ultrasound gray level analysis for preterm delivery. STUDY DESIGN: Sixty-eight patients with preterm labor between 20 and 35 weeks of gestation were included. When two-dimensional transvaginal ultrasound measurement of cervical length was completed, a region of interest of constant size was defined in the midsection of the posterior wall, and the tissue-specific gray scale was determined. Preterm delivery of <37 weeks of gestation was sought. RESULTS: Twenty-eight patients (41.2%) were delivered preterm. The risk for preterm delivery was increased significantly in patients with cervical length of /=4 (odds ratio, 3.44; 95% CI, 1.21-9.75), and with decreased mean gray scale value (odds ratio, 12.13; 95% CI, 3.69-39.88). Parity and uterine contractions were not significant as predictors for preterm delivery, although the risk for preterm delivery increased with higher parity (odds ratio, 1.8; 95% CI, 0.68-4.79). The risk for preterm delivery remained nearly the same by uterine contractions (odds ratio, 0.92; 95% CI, 0.28-3.01). A mean scale value of 相似文献   

Comparison of clinical estimation of fetal weight at the beginning and end of labor.

OBJECTIVE: To compare the accuracy of clinically estimated fetal weight (EFW) obtained at the beginning and end of labor. METHODS: The clinical EFWs obtained by obstetricians at the beginning (initial EFW) and end (repeat EFW) of labor were compared to determine the accuracy of the estimates in 138 women with term pregnancies. RESULTS: The initial clinical EFW was changed by obstetricians in 65% of patients over the course of their labor. There was a 66% chance that the repeat EFW was more accurate than the initial EFW (P=0.003). This increased to 78% when the difference between the initial and repeat EFW was more than 300 g (P=0.04). Duration and speed of labor, and change in fetal station were not correlated with a lower, higher, or more accurate EFW. CONCLUSION: The improved accuracy of a clinical EFW obtained at the end of labor is important for management decisions, such as whether to attempt operative vaginal delivery.     

Comparison of elastosonography and digital examination of cervix for consistency to predict successful vaginal delivery after induction of labor with oxytocin

Objective: To compare elastosonography and digital examination of cervix for consistency in the prediction of successful vaginal delivery.

Methods: A total of 64 pregnant women with the indication of induction of labor (IOL) were enrolled to the study. The uterine cervix is evaluated before and after the IOL with elastosonography and digital examination for consistency and sonography for length. Methods were compared in regard to the prediction of successful vaginal delivery.

Results: The median of gestational age was 41.00 (IQR?=?2.32). Out of 64 participants, 40 (62.5%) had vaginal delivery and 24 (37.5%) had cesarean delivery. The preinduction and postinduction elastosonographic indices were insignificant in delivery groups. The preinduction and postinduction evaluations of cervical consistency with digital examination were significant within vaginal delivery group (p?=?0.046), whereas it was insignificant within cesarean delivery group and between the delivery groups. The preinduction and postinduction Bishop scores were significant within vaginal delivery group (p?=?0.005), whereas it was insignificant within cesarean delivery group and between the delivery groups. Postinduction Bishop score was significant between the delivery groups.

Conclusion: Evaluation of cervix for consistency with either elastosonography or digital examination was found to be insignificant in prediction of successful vaginal delivery after IOL with oxytocin.     

Comparative efficacy and safety of vaginal misoprostol versus dinoprostone vaginal insert in labor induction at term: a randomized trial

Objective  To compare efficacy and safety of vaginal misoprostol (PGE₁ analog) with dinoprostone (PGE₂ analog) vaginal insert for labor induction in term pregnancies. Study design  A total of 112 women with singleton pregnancies of ≥37 weeks of gestation, and low Bishop scores underwent labor induction. The subjects were randomized to receive either 50 μg misoprostol intravaginally every 4 h to a maximum of five doses or a 10 mg dinoprostone vaginal insert for a maximum of 12 h. Time interval from induction to vaginal delivery, vaginal delivery rates within 12 and 24 h, requirement of oxytocin augmentation, incidence of tachysystole and uterine hyperstimulation, mode of delivery, rate of cesarean section due to fetal distress and neonatal outcome were outcome measures. Student’s t test, Chi square test, Fischer’s exact test were used for statistical analysis. Results  Time interval from induction to vaginal delivery was found to be significantly shorter in misoprostol group when compared to dinoprostone subjects (680 ± 329 min vs. 1070 ± 435 min, P < 0.001). Vaginal delivery rates within 12 h were found to be significantly higher with misoprostol induction [n = 37 (66%) vs. n = 25 (44.6%); P = 0.02], whereas vaginal delivery rates in 24 h did not differ significantly between groups [n = 41 (73.2%) vs. n = 36 (64.2%); P = 0.3]. More subjects required oxytocin augmentation in dinoprostone group [n = 35 (62.5%) vs. n = 20 (35.7%), P = 0.005] and cardiotocography tracings revealed early decelerations occurring more frequently with misoprostol induction (10.7 vs. 0%, P = 0.03). Tachysystole and uterine hyperstimulation, mode of delivery, rate of cesarean sections due to fetal distress and adverse neonatal outcome were not demonstrated to be significantly different between groups (P = 1, P = 0.5, P = 0.4, P = 0.22, P = 0.5). Conclusion  Using vaginal misoprostol is an effective way of labor induction in term pregnant women with unfavorable cervices, since it is associated with a shorter duration of labor induction and higher rates of vaginal delivery within 12 h. Misoprostol and dinoprostone are equally safe, since misoprostol did not result in a rise in maternal and neonatal morbidity, namely, tachysystole, uterine hyperstimulation, cesarean section rates and admission to neonatal intensive care units as reported previously in literature.     

Ultrasound and clinical predictors for Caesarean delivery after labour induction at term

OBJECTIVE: To assess the relationship of ultrasound assessment for amniotic fluid, fetal weight, cervical length, cervical funneling and clinical factors on the risk of Caesarean delivery after labour induction at term. METHODS: On hundred and fifty-two women scheduled for labour induction at term agreed to participate. Sonography was performed to obtain fetal biometry, amniotic fluid index and cervical length and to detect funneling at the internal cervical os. The sonographic findings were concealed. Study women received standard care during labour induction. RESULTS: On univariate analysis using Fisher's exact test, parity, cervical length and Bishop score were associated with Caesarean delivery. Following multivariable logistic regression analysis, only nulliparity (adjusted odds ratio (AOR) 5.2 (95% CI 2.2-12.2): P<0.001) and transvaginal ultrasound-determined cervical length of more than 20 mm (AOR 2.8 (95% CI 1.0-7.4): P=0.04) were independent predictors of Caesarean delivery in labour induction. Maternal age, maternal height, gestational age, indication for labour induction, amniotic fluid index, cervical funneling and ultrasound-estimated fetal weight did not predict Caesarean delivery. CONCLUSION: In women who had undergone labour induction at term with a singleton fetus, nulliparity and cervical length of more than 20 mm on transvaginal sonography were independent predictors of Caesarean delivery. This information is helpful for pre-induction counselling.