Improving Labor Induction With Ultrasound: A Systematic Review

IntroductionLabor induction is performed when continuing the pregnancy poses a greater risk than ending it. Elastography is emerging as an increasingly relevant technique to predict the success of labor induction. ObjectiveTo evaluate the relevant literature regarding elastography as a predictive tool for the success of labor induction, resulting in an uncomplicated vaginal delivery. MethodologyA systematic review was conducted on the predictive accuracy of elastography in labor induction, using PubMed, Scopus, and the Cochrane Library. A total of 10 studies were selected, covering the period from 2007 to 2022. The included studies were clinical trials and observational studies that analyzed elastography in predicting the success of induced labor. Success was defined as the completion of labor via vaginal delivery without maternal or neonatal complications. ResultsThe elastography technique demonstrates an increased accuracy in predicting successful labor induction and vaginal delivery compared to the traditional use of Bishop score. Among other predictors of labor induction failure, defined as labor ending in a cesarean delivery, are: cervical length (Odds Ratio [OR] OR = 1.916; 95% Confidence Interval [1.451-2.530]), maternal age [≥]35 years, and body mass index (BMI) [≥]30 kg/m2 (OR = 2.257; 95% CI [1.353-3.767]). However, parity decreases the probability of labor induction failure (OR = 0.129; 95% CI [0.063-0.265]). DiscussionThe reviewed scientific evidence suggests that the use of elastography before induction improves the chances of a successful labor induction. Therefore, the right moment for the labor induction based on a clinical decision should be supplemented with other objective methods such as the elastography helping to evaluate the potential success of the induction and therefore, helping to improve maternal and infant health outcomes. Further research is recommended on the comparative effectiveness of different methods to identify the optimal time for labor induction, as well as to validate its clinical utility.