The value of the combined clinical and ultrasonographic findings as useful predictive parameters for the risk of cesarean delivery follwing the induction of labor

الملخص EN

Background: several studies addressed the value of the ultrasonography (cervical length) as predictive parameters for the risk of cesarean delivery following the induction of labor.

In this respect, studies that bear directly on the value of the combined clinical and ultrasonography findings as useful predictive parameters are lacking.

Objectives : this combined retrospective and prospective investigation examines the value of the combined clinical (factors in the maternal history) and ultrasonography findings as useful predictive parameters for the risk of cesarean delivery following the induction of labor.

Methods: We reviewed the clinical (maternal age, height, body mass index, parity) and ultrasonography findings (gestational age, Bishop score, ultrasonic amniotic fluid volume, fetal head position, estimated fetal weight, and transvaginal cervical length) in 458 (retrospectively)and in 32 women (prospectively) at 38 or more weeks of gestation.

This was done immediately before the induction of labor.

Logistic regression analysis was used to determine which factors could best predict the risk of cesarean delivery.

Receiver operating characteristic curves (ROC) and a re-sampling technique were used to evaluate the model's performance.

The risk scores can be converted into the probability of Cesarean delivery using the following relationship : P= 1 / 1 + e–log it (p); P = 1 / 1 + exponent [- log it (p)] and Probability of CS (Ps) as percent = 100 / 1 + exponent t [- log it (p)].

RESULTS: Complete data were obtained from a total of 458 women including 258 nulliparous and 198 multiparous women, with a mean maternal age of 31.6 ± 6.0 years ; mean height of 164.6 ± 6.8 cm; mean body mass index of 24.3 ± 5.1 and mean gestational age at delivery of 40.1 ± 1.4 weeks.

A total of 149 cesarean deliveries (32%) were performed with an overall cesarean delivery rate of 30%.

A total of 14% of these cesarean deliveries were emergency cesarean deliveries, and the rate of induction of labor was 14%.

Maternal height, BMI, parity, and transvaginal ultrasound length of cervix showed statistically significant associations with the chance of having a cesarean delivery.

There was no evidence of nonlinear association between the continuous predictors and outcome.

There were no statistically significant interactions between Bishop Score and parity and Bishop Score and transvaginal ultrasound cervical length. Conclusion: here we report that the combined clinical (parity, body mass index and height), and ultrasonography (ultrasonic transvaginal cervical length) findings are the most accurate parameters in predicting the risk of cesarean delivery following induction of labor.

A predictive model based on these parameters would allow more accurate counseling and better informed consent in the decision-making process regarding induction of labor.