LAUSR

OBJECTIVE This study sought to describe how the implementation of recent labour guidelines may affect the cesarean delivery rate in a population in Alberta. METHODS This retrospective study was conducted on primiparous women who were in labour with singleton term fetuses with cephalic presentation in Alberta from 2007 to 2016 (n = 181 738), and it used data from a perinatal database. Modelled cesarean delivery rates were calculated to determine the potential impact of the recent guidelines on the cesarean delivery rate by using the percentage of cesarean deliveries that occurred outside the threshold of the recent labour guidelines. RESULTS A total of 21.7% of the cesarean deliveries for dystocia occurred outside of the guidelines related to the first stage of labour arrest for spontaneous labour (n = 9282), and 45.4% occurred outside of the guidelines related to the first stage of labour arrest for induced labours (n = 11 712). A total of 69.0% of the cesarean deliveries for dystocia occurred outside of the failed induction of labour guidelines (n = 4921), and 55.4% occurred outside of the second stage labour arrest guidelines (n = 6632). Assuming that the labour arrest guidelines are effective at reducing the cesarean delivery rate 25% of the time, the cesarean delivery rate for primiparous women in labour would be reduced from 22.5% to 20.7%. Assuming a 75% adherence/effectiveness rate, the cesarean delivery rate would be reduced to 17.1%. CONCLUSION The recent labour guidelines have the potential to have a substantial impact on the intrapartum cesarean delivery rate in primiparous women with singleton fetuses with cephalic presentation at term if the guidelines are put into practice.