Comparison of digital and ultrasonographic examination of the cervix in predicting time interval from induction to delivery in women with a low Bishop score

OBJECTIVE: To compare pre-induction ultrasonographic cervical length and Bishop score in predicting time to delivery after labour induction with prostaglandins. DESIGN: Prognostic cohort study. SETTING: Tertiary referral maternity unit in a teaching hospital. POPULATION: Two hundred and sixty-six women with singleton pregnancies at between 34(+0) and 41(+3) weeks of gestation requiring induction of labour with prostaglandins for medical indications. METHODS: A secondary analysis of a trial comparing two prostaglandins. Assessment of the Bishop score and measurement of the cervical length by transvaginal sonography were performed by two operators, blinded to each other's results. We estimated the predictive effects on the outcomes of ultrasonographic cervical length and Bishop score. MAIN OUTCOME MEASURE: Time intervals from induction to delivery and to vaginal delivery. RESULTS: Cervical length and Bishop score were associated with the time interval from induction to delivery, based on univariable analyses. When considered jointly in a multivariable model, only the Bishop score was significantly related to the outcome: The higher the Bishop score, the higher the hazard to delivery [hazard ratio (HR): 1.2, 95% confidence interval (CI): 1.1-1.3], illustrating that once the Bishop score is taken into account, further knowledge of cervical ultrasound length (HR: 0.99, 95% CI: 0.98-1.0) did not add any predictive information. Also, Bishop score was predictive of time interval between induction and vaginal delivery (HR: 1.2, 95% CI: 1.1-1.4) while cervical length had no additional predictive value (HR: 0.99, 95% CI: 0.98-1.0) when both cervical length and Bishop score were introduced in the model. CONCLUSIONS: The Bishop score appears to be a better predictor of the time interval from induction to delivery and to vaginal delivery than cervical length after induction of labour for medical reasons.     

Factors affecting the likelihood of successful induction after intravaginal misoprostol application for cervical ripening and labor induction

OBJECTIVE: Our purpose was to determine whether maternal age, height and weight, parity, duration of pregnancy, cervical dilatation or Bishop score, and birth weight could be used to predict the likelihood of successful induction in women given intravaginal misoprostol. STUDY DESIGN: A computerized database was compiled of 1373 pregnancies in which intravaginal misoprostol was given for cervical ripening and labor induction. Most of these women were placed on investigational protocols in which the dose of misoprostol administered was 25 to 50 microg and the dosing intervals ranged from 3 to 6 hours. No more than 24 hours of administration was permitted. Induction was undertaken in women with unfavorable cervical examinations (Bishop scores of 4 or less) and without spontaneous labor or ruptured membranes. Univariate and stepwise multiple regression analyses were performed to identify those factors associated with successful induction, defined as vaginal delivery within 24 hours of induction. RESULTS: Six hundred fifty-seven (48%) had successful induction. Parity (odds ratio [OR] 2.5, 95% CI 2.0-2.9, P <.0001), initial cervical dilatation (OR 1.9, 95% CI 1.6-2.3, P <.0001), Bishop score (OR 1.6, 95% CI 1.3, 1.8, P <.0001), and gestational age at entry (OR 1.3, 95% CI 1.1-1.5, P =.002) were significant at the.05 level for predicting successful induction. A multivariate stepwise logistic regression was then performed to evaluate each of these as independent predictors. Parity (OR 2.4, 95% CI 2.0-3.0, P <.0001), initial cervical dilatation (OR 1.7, 95% CI 1.4-2.1, P <.0001), and estimated gestational age (OR 1.3, 95% CI 1.1-1.6, P =.003) are significant independent predictors for successful induction, but initial Bishop score is not significant (P =.19) after adjustment for other significant predicting factors. CONCLUSIONS: The clinical characteristics of parity, initial cervical dilatation, and gestational age at entry are predictors of the likelihood of success of cervical ripening and labor induction with intravaginal misoprostol administration.     

Transvaginal ultrasound and digital examination in predicting successful labor induction.

OBJECTIVE: To compare transvaginal ultrasound and digital cervical examination in predicting successful induction in post-term pregnancy. METHODS: Transvaginal ultrasound and digital vaginal examinations were performed on 122 women at 41 or more weeks' gestation, immediately before labor induction. Ultrasound assessments of cervical length, dilatation, and presence of funneling were compared with the components of the Bishop score. The primary outcome was the rate of vaginal delivery. Secondary outcomes assessed included the rates of active labor in 12 hours, vaginal delivery in 12 and 24 hours, mean duration of latent phase, and induction to vaginal delivery interval. Linear and multiple logistic regression models were generated to identify factors independently associated with successful induction. RESULTS: No ultrasound characteristic predicted primary or secondary outcomes. Bishop score (odds ratio [OR] 2.98, 95% confidence interval [CI] 1.71, 5.20), cervical position (OR 4.35, 95% CI 1.41, 12.50), and maternal age (OR 1.15, 95% CI 1.01, 1.30) independently predicted vaginal delivery. Maternal weight (OR 0.96, 95% CI 0.94, 0.98), cervical dilatation (OR 6.08, 95% CI 1.70, 21.68), and effacement (OR 2.34, 95% CI 1.16, 4.73) independently predicted active labor in 12 hours. Independent predictors of vaginal delivery in 12 hours were induction method (P <.001), cervical dilatation (OR 11.16, 95% CI 3.17, 39.29), gravidity (OR 2.06, 95% CI 1.13, 3.77), and maternal weight (OR 0.96, 95% CI 0.93, 0.99). Cervical effacement (OR 2.70, 95% CI 1.59, 4.57) and parity (OR 7.10, 95% CI 2.22, 22.72) independently predicted vaginal delivery in 24 hours. Maternal weight, cervical position, and cervical dilatation were independently associated with latent phase labor duration. Factors independently associated with length of induction to delivery interval were parity, cervical effacement, and maternal weight. CONCLUSION: Transvaginal ultrasound does not predict successful labor induction in post-term pregnancy as well as digital cervical examination.     

Predictors of perinatal outcomes and economic costs for late-term induction of labour

Objective

We aimed to predict the perinatal outcomes and costs of health services following labour induction for late-term pregnancies.

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.     

Bishop score and risk of cesarean delivery after induction of labor in nulliparous women

OBJECTIVE: To quantify the risk and risk factors for cesarean delivery associated with medical and elective induction of labor in nulliparous women. METHODS: A prospective cohort study was performed in nulliparous women at term with vertex singleton gestations who had labor induced at 2 obstetrical centers. Medical and elective indications and Bishop scores were recorded before labor induction. Obstetric and neonatal data were analyzed and compared with the results in women with a spontaneous onset of labor. Data were analyzed using univariate and multivariable regression modeling. RESULTS: A total of 1,389 women were included in the study. The cesarean delivery rate was 12.0% in women with a spontaneous onset of labor (n = 765), 23.4% in women undergoing labor induction for medical reasons (n = 435) (unadjusted odds ratio [OR] 2.24; 95% confidence interval [CI] 1.64-3.06), and 23.8% in women whose labor was electively induced (n = 189) (unadjusted OR 2.29; 95% CI 1.53-3.41). However, after adjusting for the Bishop score at admission, no significant differences in cesarean delivery rates were found among the 3 groups. A Bishop score of 5 or less was a predominant risk factor for a cesarean delivery in all 3 groups (adjusted OR 2.32; 95% CI 1.66-3.25). Other variables with significantly increased risk for cesarean delivery included maternal age of 30 years or older, body mass index of 31 or higher, use of epidural analgesia during the first stage of labor, and birth weight of 3,500 g or higher. In both induction groups, more newborns required neonatal care, more mothers needed a blood transfusion, and the maternal hospital stay was longer. CONCLUSION: Compared with spontaneous onset of labor, medical and elective induction of labor in nulliparous women at term with a single fetus in cephalic presentation is associated with an increased risk of cesarean delivery, predominantly related to an unfavorable Bishop score at admission. LEVEL OF EVIDENCE: II-2.     

Elective induction of labor: failure to follow guidelines and risk of cesarean delivery

BACKGROUND: Estimate the frequency of failure to follow the French consensus guidelines for elective induction, and assess how failure affects the rate of cesarean delivery. METHODS: We compared cesarean rates according to mode of onset of labor among 5,046 low-risk patients. Violation of the guidelines was defined as induction before 38 weeks or with a Bishop score <5 or with prostaglandins. The cesarean risk was analysed with a bivariable and then a multivariable analysis, which used a multilevel logistic model. RESULTS: Women with electively induced and spontaneous labor had identical cesarean rates (4.1%). The guidelines were not followed in 23.2% of elective inductions. The risk of cesarean was higher after induction with a Bishop score <5, than after spontaneous labor (adjusted OR=4.1, 95% CI [1.3-12.9]), while elective induction with a favourable cervix did not increase the cesarean risk. In nulliparas, failure to follow the guidelines tripled the risk of cesarean (adjusted OR=3.2 [1.0-10.2]). On the other hand, elective induction of labor for women with a favourable cervix did not increase the risk of cesarean over the risk with spontaneous labor. CONCLUSION: Elective induction does not appear to increase the cesarean rate when the guidelines are met. Electively inducing labor with a low Bishop score increased the risk of cesarean, especially in nulliparas.     

Models for the prediction of successful induction of labor based on pre-induction sonographic measurement of cervical length.

OBJECTIVE: To examine the effect of pre-induction cervical length, parity, gestational age at induction, maternal age and body mass index (BMI) on the possibility of successful delivery in women undergoing induction of labor. METHODS: In 822 singleton pregnancies, induction of labor was carried out at 35 to 42(+6) weeks of gestation. The cervical length was measured by transvaginal sonography before induction. The effect of cervical length, parity, gestational age, maternal age and BMI on the interval between induction and vaginal delivery within 24 hours was investigated using Cox's proportional hazard model. The likelihood of vaginal delivery within 24 hours and risk for cesarean section overall and for failure to progress was investigated using logistic regression analysis. RESULTS: Successful vaginal delivery within 24 hours of induction occurred in 530 (64.5%) of the 822 women. Cesarean sections were performed in 161 (19.6%) cases, 70 for fetal distress and 91 for failure to progress. Cox's proportional hazard model indicated that significant prediction of the induction-to-delivery interval was provided by the pre-induction cervical length (HR=0.89, 95% CI 0.88-0.90, p<0.0001), parity (HR=2.39, 95% CI 1.98-2.88, p<0.0001), gestational age (HR=1.13, 95% CI 1.07-1.2, p=or<0.0001) and birth weight percentile (HR=0.995, 95% CI 0.99-0.995, p=0.001), but not by maternal age or BMI. Logistic regression analysis indicated that significant prediction of the likelihood of vaginal delivery within 24 hours was provided by pre-induction cervical length (OR=0.86, 95% CI 0.84-0.88, p<0.0001), parity (OR=3.59, 95% CI 2.47-5.22, p<0.0001) and gestational age (OR=1.19, 95% CI 1.07-1.32, p=or<0.0001) but not by BMI or maternal age. The risk of cesarean section overall was significantly associated with all the variables under consideration, i.e., pre-induction cervical length (OR=1.09, 95% CI 1.06-1.11, p<0.0001), parity (OR=0.25, 95% CI 0.17-0.38, p<0.0001), BMI (OR=1.85, 95% CI 1.24-2.74, p=0.0024), gestational age (OR=0.88, 95% CI 0.78-0.98, p=0.0215) and maternal age (OR=1.04, 95% CI 1.01-1.07, p=0.0192). The risk of cesarean section for failure to progress was also significantly associated with pre-induction cervical length (OR=1.11, 95% CI 1.07-1.14, p<0.0001), parity (OR=0.26, 95% CI 0.15-0.43, p<0.0001), gestational age (OR=0.83, 95% CI 0.73-0.96, p=0.0097) and BMI (OR=2.07, 95% CI 1.27-3.37, p=0.0036). CONCLUSION: In women undergoing induction of labor, pre-induction cervical length, parity, gestational age at induction, maternal age and BMI have a significant effect on the interval between induction and delivery within 24 hours, likelihood of vaginal delivery within 24 hours and the risk of cesarean section.     

Variables that predict the success of labor induction

BACKGROUND. To analyze the clinical and sonographic variables that affect the success of labor induction. METHODS. Bishop score, cervical length, and parity were studied in 196 pregnant women in the prediction of successful vaginal delivery within 24 hr of induction. Logistic regression and segmentation analysis were performed. RESULTS. Cervical length [odds ratio (OR) 1.089, P<0.001], Bishop score (OR 0.751, P=0.001), and parity (OR 6.85, P<0.001) predict the success of labor induction. The best cut-off points for cervical length were <16.5, 16.5--27, and >27 mm (P=0.0016). In the analysis of the Bishop score, we also obtained three discriminatory points, 0, 1--4, and >4 (P=0.0006), that best predict the labor induction. Finally, in a global analysis of the variables studied, the best statistic sequence that predicts the labor induction was found when we introduced parity in the first place. The success of labor induction in nulliparous was 50.77 and 83.33% in multiparous (P=0.0001). CONCLUSIONS. Cervical length, Bishop score, and parity predict the success of labor induction.     

Transvaginal ultrasonography of the uterine cervix before induction of labor]

OBJECTIVE: To compare the Bishop score and transvaginal ultrasonographic measurement of cervical length for predicting the mode of delivery following medically indicated induction of labor in term patients. METHOD: The study was conducted prospectively among 134 women who required medically indicated induction of labor. Inclusion criteria were singleton pregnancy, gestational age > or = 37 weeks of amenorrhea, cephalic presentation, and intact fetal membranes. Transvaginal ultrasonography was performed for measurement of the cervical length but the patients were managed without considering this parameter. A receiver-operating characteristic curve was constructed to determine the best cut-of value of cervical length for predicting the risk of cesarean section following induction of labor. RESULTS: Thirty six patients (26.9%) underwent cesarean section and cervical dilatation at time of the cesarean section was < 8 cm in 25 cases. The Bishop score was not predictive for the mode of delivery in this study. In contrast, the cesarean section rate was significantly lower in women with a uterine cervix < 26 mm (18.9 vs 36.6%, p = 0.02). Moreover, the difference has concerned only the cesarean sections performed before 8 cm dilatation (9.5 vs 30.0%, p = 0.002). CONCLUSION: Cervical length measured with transvaginal ultrasonography is a better predictor than the Bishop score for predicting the risk of cesarean section following medically indicated induction of labor.     

Extra-amniotic saline infusion increases cesarean risk versus other induction methods and spontaneous labor

Extra-amniotic saline infusion (EASI) via a Foley catheter has been thought to be comparable in efficacy to other induction and cervical ripening methods. This study examines the risk of cesarean delivery associated with EASI compared with spontaneous labor and other methods of cervical ripening. A retrospective cohort study based upon deliveries at Bellevue Hospital Center from August 2000 to December 2002 was conducted. Three groups were identified: EASI, other methods of induction such as prostaglandins and oxytocin administration, and spontaneous labor. Pairwise comparisons were performed using analysis of variance and multivariate logistic regression analysis to control for confounding variables. There were 625 charts evaluated: including 171 with EASI, 190 with other induction methods, and 264 with spontaneous labor. The rates of cesarean section were 33.9%, 17.9%, and 7.2%, respectively. When compared with spontaneous labor, there was a higher risk of cesarean delivery for subjects induced with other methods (adjusted odds ratio [OR], 2.4; 95% confidence interval [CI], 1.3 to 4.5; P < 0.001), and for those induced with EASI (adjusted OR, 5.5; 95% CI, 3.1 to 9.9; P < 0.001). When EASI was compared with other methods of induction, the risk of cesarean delivery was still increased (adjusted OR, 2.3; 95% CI, 1.4 to 3.8; P = 0.001). EASI is associated with an increased risk of cesarean delivery compared with spontaneous labor and other methods of cervical ripening.     

The labor induction: integrated clinical and sonographic variables that predict the outcome.

OBJECTIVE: To analyze the clinical and sonographic variables that predicts the success of labor induction. STUDY DESIGN: We studied the Bishop score, cervical length and parity in 196 pregnant women in the prediction of successful vaginal delivery within 24 h of induction. Logistic regression and segmentation analysis were performed. RESULTS: Cervical length (odds ratio (OR) 1.089, P<0.001), Bishop score (OR 0.751, P=0.001) and parity (OR 4.7, P<0.001) predict the success of labor induction. In a global analysis of the variables studied, the best statistic sequence that predicts the labor induction was found when we introduced parity in the first place. The success of labor induction in nulliparous was 50.8 and 83.3% in multiparous women (P=0.0001). CONCLUSIONS: Cervical length, Bishop score and parity, integrated in a flow chart, provide independent prediction of vaginal delivery within 24 h of induction.     

Sonographic cervical length measurement before labor induction in term nulliparous women

OBJECTIVE: The purpose of the study was to determine if transvaginal sonographic measurement of the cervical length is a useful method to predict successful labor induction in nulliparas. METHODS: 137 women who were scheduled for medically indicated induction of labor had a transvaginal sonographic measurement of the cervical length before labor induction. Inclusion criteria were: (1) singleton pregnancy; (2) gestational age between 37-42 weeks; (3) live fetus in cephalic presentation; (4) intact membranes; (5) no vaginal bleeding; (6) no previous history of uterine surgery; (7) nulliparous women, and (8) no allergy or asthma in response to prostaglandins. Induction of labor was performed within 6 h of the ultrasonographic examination, by inserting 2 mg of dinoprostone in the posterior vaginal fornix, repeated if needed every 6 h for up to three doses. When the cervix became favorable and no regular contractions were observed, amniotomy and oxytocin augmentation, starting at 1 mIU/min and increasing 1 mIU every 30 min as necessary, was performed. RESULTS: All women were Caucasians and the mean age was 24.3 years (range 19-37 years). The mean cervical length was 28 mm (range 11-39 mm). The Bishop score was < or =5 in 101 women and >5 in the 36 others. Vaginal delivery occurred in 92 women (67.1%), and the vast majority of them (89 women; 96.7%) gave birth within 24 h of induction. Forty-five women (32.8%) had a cesarean section. The Bishop score was not predictive of the mode of delivery. Thirty-six of 101 women (35.6%) with a Bishop score < or =5 delivered by cesarean section, compared to 9 of 36 women with a Bishop score >5 (25%) (p = NS). Women with a cervical length <27 mm were more likely to deliver vaginally. Using this cutoff value the sensitivity of a successful labor induction was 76% and the specificity was 75.5%. CONCLUSIONS: Transvaginal sonographic measurement of cervical length is a good predictor of a successful labor induction at term in nulliparas.     

Ultrasonographic cervical length measurement is not a better predictor of preterm delivery than digital examination in a population of patients with idiopathic preterm labor

OBJECTIVE: To compare digital and ultrasonographic cervical examination for the prediction of preterm delivery in patients hospitalized for preterm labor. STUDY DESIGN: Fifty-nine patients were included. The Bishop score was evaluated upon admission, weeks gestational age. Ultrasonographic measurement of cervical length was done within 24h after entry. Delivery before 37 weeks gestational age was the primary endpoint. Attending obstetricians were blinded to the results of echography. RESULTS: Preterm delivery rate was 39% (23/59). The risk of preterm delivery was significantly increased when the Bishop score was greater than or equal to 6 (OR = 4.45 [1.41-14.01]) or when ultrasonographic cervical length was less than or equal to 27 mm (OR = 4.04 [1.32-12.3]), but digital examination was the only independent risk factor in multivariate analysis. Sensitivity, specificity, positive and negative predictive value for digital examination and ultrasonography were respectively 74, 61, 55 and 79%, 70, 64, 55 and 77%. Combination of digital examination and ultrasonography did not yield better results. CONCLUSION: In our series, prediction of preterm delivery was not improved by ultrasonography compared to digital examination. The size of the cervical shift observed in most patients hospitalized for preterm labor may render ultrasonography less relevant in identifying patients anticipated to deliver prematurely.     

Transvaginal ultrasonographic cervical measurement as a predictor of successful labor induction

OBJECTIVE: Our purpose was to compare transvaginal cervical measurement and the Bishop score as indicators of duration of labor and successful induction of labor at term.Study Design: This prospective observational study recruited women with singleton gestations scheduled for induction of labor at > or =37 weeks. Transvaginal ultrasonographic measurement of cervical length was performed and the Bishop score was determined, each by operators masked to the other measurement. Data were collected on parity, gestational age, mode of delivery, induction agent, induction-to-delivery interval, Bishop score, and cervical length measurement. RESULTS: A total of 77 women were analyzed. Vaginal delivery occurred in 69%. Both Bishop score and cervical length showed linear correlation with duration of labor (R(2) = 0.43, P <. 001; R(2) = 0.48, P <.001; respectively). Women with cervical length <3.0 cm had shorter labors (P <.001) and were more likely to be delivered vaginally (P <.001). Women with a Bishop score >4 also had shorter labors and were more likely to be delivered vaginally, with similar P values. A logistic regression model identified cervical length and parity as the only independent predictors of vaginal delivery. CONCLUSIONS: Both ultrasonographically measured cervical length and Bishop score predict duration of labor and likelihood of vaginal delivery. However, only cervical length and parity were independent predictors of mode of delivery.     

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.     

Unsucessful labour induction in women with unfavourable cervical scores: predictors and management

BACKGROUND: Misoprostol fails to induce labour in 5-20% of women at term. AIM: To analyse possible predictors of unsuccessful induction with 50 microg vaginal misoprostol and effectiveness and the safety of intracervical Foley catheter application in induction failures. METHODS: An observational study was conducted on 1030 women with singleton, live fetuses, vertex presentation, > 34 weeks of gestation and Bishop score < 5. Induction of labour with 50 microg vaginal misoprostol repeated every 6 h was attempted. Women without regular uterine contractions and cervical changes at the end of 24 h were considered to be unsuccessful, and a transcervical Foley balloon catheter was placed and inflated with 50 mL saline. Possible predictors of induction failures were analysed via logistic regression analysis. Neonatal outcomes and vaginal delivery achieved after Foley catheter were also determined. RESULTS: Induction was successful in 918 cases (89.1%) and Foley catheter was placed in 112 (10.8%) women. Increasing gestational age in weeks (odds ratio [OR] 0.77, 95% confidence interval [CI] 0.68-0.88) and increasing Bishop score (OR 0.73, 95% CI 0.60-0.90) decreased the risk of failed induction. Failure rates were 16% (27/169) in post-term nulliparous women with Bishop score 相似文献   

Prostaglandin E2 induction of labor for isolated oligohydramnios in women with unfavorable cervix at term

OBJECTIVE: To evaluate the maternal and neonatal outcomes of pregnancies complicated with isolated oligohydramnios at term, managed by induction of labor. METHODS: We conducted a retrospective case-control study. 138 women with uncomplicated oligohydramnios at term [amniotic fluid index (AFI) < or =5 cm] and a low Bishop score (< or =6) underwent induction of labor with prostaglandin E2. These women were compared to 67 women who underwent induction of labor at 42 weeks' gestation and 276 women at low-risk pregnancy and spontaneous onset of labor, matched for parity and race. RESULTS: Cesarean section (CS) rate was similar in the study and the post-date group (17.4 and 17.9%, respectively), but significantly higher than the spontaneous labor group (5.8%, OR 3.42, 95% CI 1.75-6.68). No differences were found with other outcomes. CONCLUSION: Pregnancies with isolated oligohydramnios at term apparently are not at higher risk of perinatal complications, but induction of labor is associated with increased rate of CS.     

Short-term maternal and neonatal outcomes by mode of delivery. A case-controlled study

OBJECTIVE: Side-by-side comparisons of short-term maternal and neonatal outcomes for spontaneous vaginal delivery, instrumental vaginal delivery, planned caesarean section and caesarean section during labor in patients matched for clinical condition, age, and week of gestation are lacking. This case-controlled study was undertaken to evaluate short-term maternal and neonatal complications in a healthy population at term by mode of delivery. STUDY DESIGN: Four groups of healthy women, with antenatally normal singleton pregnancies at term, who underwent instrumental vaginal delivery (no. 201), spontaneous delivery (no. 402), planned caesarean section without labor (no. 402) and caesarean section in labor (no. 402) have been retrospectively selected. Outcome measures were maternal and neonatal short-term complications. Odds ratios (OR) and 95% confidence intervals (CI) were calculated. RESULTS: Maternal complications were mostly associated with forceps-assisted and vacuum-assisted instrumental deliveries (OR: 6.9; 95% CI: 2.9-16.4 and OR 3.0; 95% CI 1.1-8.8, respectively, versus spontaneous deliveries). No significant differences in overall complications were observed between spontaneous vaginal deliveries and caesarean sections, whether planned or in labor. By comparison with caesarean sections in labor, instrumental deliveries significantly increased the risk of complications (OR: 3.2; 95% CI: 1.6-6.5). Neonatal complications were also mostly correlated with forceps-assisted and vacuum-assisted instrumental deliveries (OR: 3.5; 95% CI: 1.9-6.7 and OR 3.8; 95% CI 2.0-7.4, respectively, versus spontaneous deliveries). By comparison with caesarean sections in labor, instrumental vaginal deliveries significantly increased the risk of complications (OR: 4.2; 95% CI: 2.4-7.4). CONCLUSIONS: In healthy women with antenatally normal singleton pregnancies at term, instrumental deliveries are associated with the highest rate of short-term maternal and neonatal complications.     

Association and risk factors between induction of labor and cesarean section

Abstract

Objective: To determine risk factors and to quantify the risk of cesarean section (CS) associated with labor induction.

Method: A prospective controlled study of women admitted for labor induction with PGE2 in a single tertiary medical center. Outcome was compared with women who presented with spontaneous onset of delivery.

Results: The induction group were characterized by a higher body mass index (BMI), lower Bishop score and a higher cervical length at presentation compared with controls. Labor induction with PGE2 was associated with increased risk of CS (14.8% versus 4.5%, p?=?0.02). This association persists after adjustment for potential confounders including Bishop score at presentation (OR?=?2.9, 95% CI 1.03–11.8). The risk of CS was especially high for nulliparous (24.4% versus 5.1%, p?=?0.02), overweight (21.2% versus 3.7%, p?=?0.047), induction at <40 weeks of gestation (22.2% versus 2.2%, p?=?0.004), in Bishop score <4 (18.2% versus 4.5%, p?=?0.03), cervical length >25?mm (19.2% versus 4.5%, p?=?0.005), or intact membranes (25.0% versus 4.5%, p?=?0.02) at presentation.

Conclusions: Labor induction with PGE2 is associated with increased risk of CS. These data should be taken into consideration when deciding on labor induction, especially in the absence of clear medical indication.