Aim: To determine the accuracy of cervical elastography in predicting labor induction success.
Materials and methods: A systematic search, review, and meta-analysis of observational studies published in English language between January 2000 and October 2014 was performed. It included studies considering cervix sonoelastography as the index test and successful labor or vaginal delivery as the reference standard. As cervix length and Bishop score were considered comparator tests, the quality of the included studies was assessed using quality assessment tool for diagnostic accuracy studies (QUADAS) tool.
Results: A total of four studies assessing 323 women before medical induction of labor were included. Cervical elastography, cervical length, and Bishop score showed a diagnostic odds ratio (DOR) with 95% confidence interval (CI) for successful labor prediction of 3.50 (1.93-6.35), 3.35 (1.94-5.77), and 1.45 (0.33-6.41), respectively. In addition, cervical elastography, cervical length, and Bishop score showed a DOR with 95% CI for successful vaginal delivery prediction of 5.24 (3.23-8.50), 4.94 (2.72-8.98), and 4.62 (0.69-30.94), respectively. Considering the summary of receiver operating characteristic curves we show that cervical elastography or length are similarly reliable, and both are more reliable to predict successful labor than the Bishop score. Two studies were excluded because it was not possible to retrieve data for the meta-analysis. Among the excluded studies, one found no significant contribution from elastography for prediction of successful labor induction.
Conclusions: Even though there is a limited number of studies included and the heterogeneity of the methods used, cervical elastography seems to be a promising tool for predicting successful labor induction and vaginal delivery in women treated by medical induction of labor.