Effect of a perineal protection device in vacuum-assisted vaginal births – a prospective, randomized-controlled interventional trial

Introduction Birth tears are common in vaginal births, especially in vaginal-assisted births. As birth trauma can cause short- and long-term maternal morbidity, effort should be made to improve maternal outcomes. One option is the improvement of perineal protection during birth. With our study, we planned to evaluate the effect of a perineal protection device in vacuum-assisted births on the rate of birth tears in the posterior compartment, as well as its feasibility and safety.

Material and Methods In a prospective, randomized-controlled interventional trial from 7/2020 to 10/2022 we evaluated the application of a perineal protection device in vacuum-assisted vaginal births in a tertiary care center, including 1574 women with singletons≥37 weeks of gestation. The primary composite outcome was the rate of low-grade perineal and vaginal tears in the posterior compartment. Secondary outcomes were the rate of high-grade perineal tears, and the feasibility and safety of the device for mother and child. Descriptive statistics and a logistic regression analysis were performed in an "intention-to-treat" (ITT), a "per-protocol" (PP) and an "as-treated" (AT) analysis, using SPSS version 29.0.0.0 (IBM SPSS, Armonk, New York, USA). A p-value<0.05 was considered statistically significant.

Results 1574 women gave their written informed consent for study participation. At birth, 249 women had an indication for vacuum-assisted vaginal birth, of which 217 were randomized. Another eight women were excluded because of birth ending without vacuum-assistance. Of the remaining 209 women, 105 formed the intervention group (application of the device), whereas 104 formed the control group (without application of the device). No differences in primary and secondary outcomes were found in the ITT and PP analysis. For the AT analysis, 68 of the 105 women (65%) remained in the intervention group after exclusion of 37 (35%) women with failed application of the device. By this, 141 formed the control group. In the AT analysis, no differences in primary and secondary outcomes were found, but significant less women in the intervention group received a mediolateral episiotomy (29% vs 45%, p-value 0.034). No adverse outcomes for mother and child were seen. In some cases the device was difficult to place correctly and/or keep in place.

Conclusion The perineal protection device is mostly easy to apply and without harm for the mother and child. It was not able to reduce spontaneous birth tears in the posterior compartment in women giving birth by vacuum-assistance, but was associated with a lower rate of episiotomies, if the device has been used correctly.

Publication History

Article published online:
15 November 2023