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Background: Induction of labor is carried out in approximately 20% of pregnancies. However, approximately 20% of women having induction of labor end up having a Cesarean delivery. The traditional method of predicting whether an induced labor will result in successful vaginal delivery is based on the preinduction "favorability" of the cervix as assessed by the Bishop score. However, this assessment is subjective and several studies have shown a poor predictive value for the outcome of induction., Objectives: To examine the relationship between preinduction sonographically measured cervical length and the Bishop score and to compare the two measurements in the prediction of successful vaginal delivery within 24 h of induction., Methods: In this multicenter study, preinduction cervical assessment was undertaken in 240 women with singleton pregnancies at 37-42 weeks of gestation. The Bishop score was assessed by digital examination and the cervical length was measured by transvaginal sonography., Results: Multiple regression analysis demonstrated that cervical length, Bishop score and parity provided independent contribution in the prediction of the likelihood of delivering vaginally within 24 h. Further examination of the different components of the Bishop score showed that only cervical length provided a significant contribution in the prediction of the likelihood of vaginal delivery within 24 h. In the receiver operating characteristic curves, the best cut-off point for the prediction of successful induction was 28 mm for cervical length and 3 for the Bishop score. However, cervical length appears to be a better predictor than the Bishop score, with a sensitivity of 0.87 and a specificity of 0.71 compared to 0.58 and 0.77, respectively. Similarly, the Kaplan-Meier survival curves indicate that better discriminatory results in the prediction of vaginal delivery within 24 h are achieved using cervical length rather than the Bishop score., Conclusion: Transvaginal sonographic measurement of cervical length provides a useful prediction of the likelihood of vaginal delivery within 24 h of induction.

Study objectives: To evaluate the three commonly used indices of Doppler blood flow resistance in clinical practice for the uterine artery. By assessing the measures of central tendency, dispersion, and variation, to determine the most appropriate index for clinical use transabdominally in the second half of pregnancy. Methods: A prospective study of uterine artery Doppler measurement in singleton pregnancies between 18 and 32 weeks gestation. Using previously described methods, two independent measurements were obtained transabdominally from each side in all subjects. The systolic/diastolic ratio (SD ratio), pulsatility index (PI), and resistance index (RI) were recorded from both the right and left uterine artery in turn. All measurements were obtained by a single operator (MOT) using the same machine (Philips SD 800). The results were analyzed statistically for the measures of dispersion, distribution, and the variation explained. Results: There were 1796 observations from 449 subjects in total, with the SD ratio showing the widest dispersion. The PI measurements were intermediate with respect to both, while the RI showed the least dispersion. The RI distribution was the closest to a naturally distributed (Gaussian) pattern, followed by the PI. The SD ratio did not appear to conform to a normal distribution. The interquartile ranges (IRQ) for the SD ratio were 0.71, 0.73 (left- and right-uterine artery, respectively); PI: 0.42, 0.41; and RI: 0.15, 0.17. The mean of three derived measurements of the RI was sufficient to account for over 99% of the observed variation. Conclusions: Differences reported between the different resistance and pulsatility Doppler indices could be due to either random or systematic error, or a combination of both. The observations from this study suggest that when the RI is used, these are kept to a minimum. These findings may be helpful in selecting the appropriate index for uterine artery Doppler screening and clinical applications... [ABSTRACT FROM AUTHOR]