Recommendations from the American College of Obstetricians and Gynecologists (ACOG) and Society for Maternal-Fetal Medicine (SFMF) about clinical practices to avoid the first cesarean birth include suggestions about oxytocin during the active phase of the first stage of labor. "Cesarean [birth] for active-phase arrest in first stage of labor should be reserved for women >6 cm of dilation with ruptured membranes who fail to progress despite 4 h of adequate uterine activity, or at least 6 h of oxytocin administration with inadequate uterine activity and no cervical change" (ACOG & SFMF, 2014. p. 183). Maternal and fetal wellbeing is continuously assessed and maintained.

Several recent studies suggest for some women, an oxytocin "rest" or discontinuing oxytocin once active labor has been established is worth consideration. In a systematic review of oxytocin discontinuation after the active phase of induced labor that included nine randomized controlled trials (RCTs), uterine "hyperstimulation," cesarean birth, and "nonreassuring" fetal heart rate (FHR) tracings were significantly higher among women with continued oxytocin in active labor compared with women with discontinued oxytocin at active labor (Hernandez-Martinez et al., 2019). A Cochrane review of 10 RCTs (Boie et al., 2018) found discontinuing oxytocin once reaching active labor was associated with less uterine tachysystole with "abnormal" FHR tracings and a possible reduction in cesarean birth. Discontinuing oxytocin at 5 cm was associated with reduced tachysystole and cesarean birth when compared with continuing oxytocin based on a meta-analysis and systematic review of nine RCTs (Saccone et al., 2017). In an RCT, excessive uterine activity and FHR abnormalities were decreased when oxytocin was discontinued at 5 cm (Bor et al., 2016). McAdow et al., (2020) results suggest an oxytocin rest of >=8 hours may be beneficial in decreasing risk of cesarean birth for women in prolonged latent phase labor.

It has long been known that there can be unintended consequences of continued increases in oxytocin during prolonged labor such as oxytocin receptor desensitization (making oxytocin less effective in producing normal uterine contractions), dysfunctional uterine activity patterns, and uterine tachysystole (Dawood, 1995; Phaneuf et al., 1998; Phaneuf et al., 2000; Robinson et al., 2003). Some researchers have found prolonged high-dose oxytocin infusions can be counterproductive to augmentation of established labor (Robinson et al.). Carefully titrating oxytocin during labor induction and augmentation is essential in supporting safe labor management. An oxytocin rest or discontinuation may be beneficial for some women in helping to achieve vaginal birth.

References