Kiwi omnicup handheld versus Mityvac M-style conventional vacuum system: a retrospective observational study

Abstract

Introduction: To improve the choice of vacuum-assisted delivery (VAD) system, we compared the outcomes of Kiwi handheld system and Mityvac M-style conventional system (both use disposable plastic cups).

Materials and methods: Retrospective observational study with data collection from electronic medical records. The study was conducted at a tertiary medical center, with approximately 7000 deliveries annually. Categorical and continuous variables were analyzed using chi-square test and t-test, respectively. p value < .05 was considered significant. The main outcomes assessed were the overall failure rate of each system, failure rates for occipito-anterior (OA) versus occipito-transverse/occipito-anterior (OT/OP) positions, +1 versus +2 fetal stations, and early maternal/neonatal outcomes.

Results: During a 10-month period, there were 507 (8.4%) attempted VADs, 36 failed (7.1%), and eight (1.5%) converted to cesarean section. Of these, 364 were Kiwi-assisted and 143 Mityvac-assisted. Background characteristics were similar. The handheld system had more failures overall (9.6 versus 0.7%), at OA (7.6 versus 0.9%), and non-OA positions (17.3% versus none), at +1 (13.25 versus 0.96%) and at +2/3 stations (6.1% versus none), than the conventional system did, respectively. There was a higher rate of early post-partum hemorrhage (15.3 versus 7.4%) in the conventional group. Both systems had similar rates of third/fourth degree perineal tears, shoulder dystocia and adverse neonatal outcomes.

Conclusions: Our results suggest more failures with Kiwi compared to Mityvac, overall and at any fetal position/station, without a significant difference in adverse outcome profile.

Keywords:

• Conventional vacuum system
• hand-held vacuum system
• Kiwi omnicup
• M-style Mityvac cup
• vacuum assisted delivery

View correction statement:

Notice of duplicate publication: ‘Kiwi OmniCup Handheld vs. Mityvac M-Style Conventional Vacuum System: a Retrospective Observational Study’

Acknowledgements

We would like to thank Ms. Nava Jelin for data analysis and Ms. Faye Schreiber for editing. They are employees of Meir Medical Center. The study was approved by the Institutional Ethics Committee in July 2016, registration number 0116-16-MMC.

Disclosure statement

The authors report no conflicts of interest.