Practices regarding the management of the 2nd stage of labor are divergent throughout the world, with even controversy concerning the best timing for the onset of pushing efforts, i.e. immediate versus delayed pushing [1]. Studies, conducted in the context of immediate pushing observe an increase in operative deliveries, i.e. instrumental and cesarean deliveries, with the increase of the 2nd stage [2], [3], [4], [5]. Conversely, delayed pushing is mainly associated with an increase in the rate of spontaneous vaginal delivery compared with immediate pushing [6], [7], [8]. However, one study by Cahill and al. did not find any difference in the rate of spontaneous vaginal delivery between immediate pushing and 1 hour delayed pushing on nulliparous women under epidural analgesia [1].

Regarding the morbidity associated with delayed pushing, studies show an increase in maternal morbidity with duration of delayed pushing, including an increase in postpartum hemorrhage and perineal tears after 3 hours [2,3,5,[9], [10], [11], [12]]. Nevertheless, delaying pushing under 3 hours does not seem to be associated with an increased risk of maternal or neonatal morbidity [2,3,5,[9], [10], [11], [12]]. Thus, recent international recommendations (RCOG 2020, WHO 2018) have suggested delaying pushing for one or two hours at most after diagnosis of full dilation [13,14] in women delivering with epidural analgesia.

In France, delayed pushing is recommended and classical practice, in women under epidural analgesia, is to delay pushing with expecting periods of one to two hours. But, the latest French guidelines did not establish a limit to duration of delayed pushing, and stated that maternal risks increased after 3 hours, particularly the risk of post-partum hemorrhage [15,16]. Consecutively, several maternity units modified their protocol allowing a third hour of passive 2nd stage before starting the pushing efforts. It, therefore, seems important to evaluate whether a third hour of delayed pushing could decrease the rate of operative deliveries without increasing perinatal morbidity.

Thus, the objective of this study was to compare two strategies of passive second stage management: three-hour vs two-hour delayed pushing after the diagnosis of full cervical dilation on mode of delivery and perinatal outcomes.