Cervical ripening and labour induction: A critical review of the available methods.

Induction of labour is one of the most common interventions experienced by pregnant women. There are two overlapping components to labour induction, which include cervical ripening and the initiation of regular contractions. A large number of clinical studies have been conducted for evaluating the methods used for induction of labour, their effectiveness and safety, and pregnancy outcomes. Randomised controlled trials (RCTs) provide the strongest form of evidence for clinical practice. These data are brought together in systematic reviews and have been incorporated into national and international guidelines. Despite this, there is considerable variation in the recommendations between guidelines. Heterogeneity between studies, inconsistency in the definitions of trial outcomes, and underpowered sample size contribute to the difficulty in making robust recommendations. There are pharmacological and non-pharmacological approaches that can be compared with each other and with placebo or no treatment. There are also complementary therapies that may appeal to women but lack evidence of their effectiveness. These issues have been addressed in the current chapter, with a critical review of the research evidence presented in clinical trials and systematic reviews.