Maternal and neonatal outcomes in vacuum-assisted delivery with the Kiwi OmniCup and Malmström metal cup

Maternal and Neonatal Outcomes of Operative Vaginal Deliveries at a Single Tertiary Center

Objectives

Our study sought to assess the maternal and neonatal outcomes of operative vaginal deliveries (OVDs) at Sultan Qaboos University Hospital (SQUH). We assessed the proportion of OVDs along with the proportion of maternal and neonatal outcomes of kiwi OmniCup vacuum, metal cup vacuum, and forceps deliveries.

Methods

We conducted a retrospective cohort study in the Obstetrics and Gynecology Department at SQUH from June 2015 to March 2018. The hospital information system was utilized to obtain records of all women who delivered at SQUH by vacuum or forceps during the study period. We collected data on maternal demographics, maternal and neonatal outcomes, and total number of deliveries.

Results

During the study period, 3.8% of deliveries were OVDs. The most common instrument used was the Kiwi OmniCup vacuum device. No significant difference was found between the type of tears and instrument used except perineal tears (p = 0.003), which was seen more in the vacuum group, particularly Kiwi OmniCup. Neonatal birth weight (p = 0.046) was significantly higher in the metallic vacuum cup group. Thirty-one neonates (6.6%) were admitted to the neonatal intensive care unit, and most were born using Kiwi OmniCup vacuum (67.7%).

Conclusions

OVD is an ideal alternative to cesarean section with fewer maternal and neonatal complications in women who cannot deliver spontaneously if performed by a well-trained obstetrician.

An engineering perspective of vacuum assisted delivery devices in obstetrics: A review

Complications during childbirth result in the need for clinicians to use 'assisted delivery' in over 12% of cases (UK). After more than 50 years in clinical practice, vacuum assisted delivery (VAD) devices remain a mainstay in physically assisting child delivery; sometimes preferred over forceps due to their ease of use and reduced maternal morbidity. Despite their popularity and enduring track-record, VAD devices have shown little evidence of innovation or design change since their inception. In addition, evidence on the safety and functionality of VAD devices remains limited but does present opportunities for improvements to reduce adverse clinical outcomes. Consequently in this review we examine the literature and patent landscape surrounding VAD biomechanics, design evolution and performance from an engineering perspective, aiming to collate the limited but valuable information from a disparate field and provide a series of recommendations to inform future research into improved, safer, VAD systems.

Birth tears after spontaneous and vacuum-assisted births with different vacuum cup systems - a retrospective cohort study

Objectives Birth tears are a common complication of vaginal childbirth. We aimed to evaluate the outcomes of birth tears first by comparing the mode of vaginal birth (VB) and then comparing different vacuum cups in instrumental VBs in order to better advise childbearing women and obstetrical professionals. Methods In a retrospective cohort study, we analyzed nulliparous and multiparous women with a singleton pregnancy in vertex presentation at ≥37 + 0 gestational weeks who gave birth vaginally at our tertiary care center between 06/2012 and 12/2016. We compared the distribution of tear types in spontaneous births (SBs) vs. vacuum-assisted VBs. We then compared the tear distribution in the vacuum group when using the Kiwi Omnicup or Bird's anterior metal cup. Outcome parameters were the incidence and distribution of the different tear types dependent on the mode of delivery and type of vacuum cup. Results A total of 4549 SBs and 907 VBs were analyzed. Birth tear distribution differed significantly between the birth modes. In 15.2% of women with an SB an episiotomy was performed vs. 58.5% in women with a VB. Any kind of perineal tear was seen in 45.7% after SB and in 32.7% after VB. High-grade obstetric anal sphincter injuries (OASIS) appeared in 1.1% after SB and in 3.1% after VB. No significant changes in tear distribution were found between the two different VB modes. Conclusions There were more episiotomies, vaginal tears and OASIS after VB than after SB. In contrast, there were more low-grade perineal and labial tears after SB. No significant differences were found between different vacuum cup systems, just a slight trend toward different tear patterns.

Adverse neonatal and maternal outcome following vacuum-assisted vaginal delivery: does indication matter?

PURPOSE

To estimate the impact of indication for vacuum-assisted vaginal delivery on neonatal and maternal adverse outcome.

METHODS

Retrospective analysis of women carrying singleton-term pregnancies undergoing vacuum-assisted vaginal delivery in a tertiary hospital (2007-2014). Cohort was stratified by indication: non-reassuring fetal heart rate or prolonged second stage. Primary outcome was adverse neonatal outcome and secondary outcome was maternal morbidity. Logistic regression analysis was utilized to adjust for potential confounders.

RESULT

Overall, 4931 women met inclusion criteria. Delivery indication was prolonged second stage in 3143 (64%) cases and non-reassuring fetal heart rate in 1788 (36%). In the non-reassuring fetal heart rate group, there were higher rates of cephalohematoma, low 5-min Apgar-score, and asphyxia. In the prolonged second-stage group, there were higher rates of sepsis and post-partum hemorrhage. Composite neonatal birth trauma and maternal morbidity were higher for vacuum-assisted vaginal delivery following prolonged second stage. Following adjustment for confounders cephalohematoma (aOR 1.21, 95% CI 1.04-1.41), low 5-min Apgar-score (aOR 2.91, 95% CI 1.26-4.67) and asphyxia (aOR 1.81 95% CI 1.35-2.44) remained significant in the non-reassuring fetal heart rate group and neonatal sepsis remained significant for the prolonged second-stage group (aOR 1.77, 95% CI 1.38-2.27), p < 0.05 for all. However, there was no longer difference in the composite birth trauma, other neonatal or maternal morbidity.

CONCLUSION

The indication for vacuum-assisted vaginal delivery has an impact on neonatal outcome. While cephalohematoma, low 5' Apgar score, and asphyxia were more common in the non-reassuring fetal heart rate group, neonatal sepsis was more common in cases of prolonged second stage of labor.

Obstetric management in vacuum-extraction deliveries

OBJECTIVE

The aim of this observational study was to describe the obstetric management in vacuum extraction (VE) deliveries and to compare these findings to instructions in clinical guidelines on VE.

METHODS

In 2013, detailed data on management of 600 VE cases were consecutively collected from six different delivery units in Sweden. Each unit also contributed their own clinical VE guideline.

RESULTS

In total, 93% of the VEs ended with a vaginal delivery while 7% failed and were converted to an emergency cesarean section. In 2.3% extraction time exceeded 20 minutes, and in 6% more than six pulls were used to deliver the fetus. Cup detachment occurred in 14.6%, and fundal pressure was used in 11% of the deliveries. In 2.3%, fetal station was assessed as above the level of the maternal ischial spines. The clinical guidelines on VE varied in scope and content between units, and were often incomplete according to best practice.

CONCLUSION

The vast majority of the VEs were conducted in accordance with safety recommendations. However, in a few extractions, safety rules were disregarded and more than six pulls or an extraction time of more than 20 minutes were used to complete the delivery.