Impact of clinical practice guidelines for vacuum-assisted delivery on maternal and neonatal outcomes in Japan: A single-center observational study.

Aim: Practice guidelines for vacuum-assisted delivery in Japan were revised in 2014 to improve clinical safety. We aimed to determine the success rates of vacuum delivery before and after the release of the revised guidelines.

Methods: This retrospective observational study included singleton deliveries at term gestation. Success rate of vacuum delivery, duration of extraction, number of tractions and maternal and neonatal injuries were compared between 2011-2014 and 2015-2019.

Results: Vacuum extraction was attempted in 249 (15%) of 1657 deliveries. Duration of extraction was shorter in 2015-2019 (median, 3.0 min; interquartile range [IQR], 1.0-5.8 min) than in 2011-2014 (median, 4.0 min; IQR, 2.0-6.5 min; P = 0.0045). No significant differences were seen in success of vacuum extraction (98%), prolonged (>20 min) duration of extraction (1.5%) and repeated (>5 pulls) tractions (3.1%) in vacuum deliveries during 2011-2014, compared to success of vacuum extraction (94%), prolonged duration of extraction (1.6%) and repeated tractions (1.1%) in those during 2015-2019. Likewise, no significant differences were identified in maternal or neonatal injuries.

Conclusion: Successful vacuum-assisted deliveries and shortened duration of extraction were still confirmed after guideline revision. However, because of consistent safe practice with vacuum delivery from before the revision, improvements in maternal and neonatal injuries were not observed.