Duration of Operative Vaginal Delivery and Adverse Obstetric Outcomes

The Association between the Number of Vacuum Pop-Offs and Adverse Neonatal Outcomes

OBJECTIVE

Obstetrical vacuum manufacturers have long recommended a maximum of two to three pop-offs be allowed before abandoning the procedure. However, there is a paucity of evidence on the safety of vacuum-assisted vaginal delivery in relation to the number of pop-offs to support this recommendation. Our objective was to examine whether the number of pop-offs in a vacuum-assisted vaginal delivery was associated with adverse neonatal outcomes.

STUDY DESIGN

This is a retrospective cohort study of women who underwent a trial of a vacuum-assisted vaginal delivery at a single tertiary care institution between October 2005 and June 2014. Maternal and fetal factors associated with the number of pop-offs were examined in bivariable analyses. Multivariable analyses were performed to determine the independent association of the number of pop-offs with adverse neonatal outcomes.

RESULTS

Of the 1,730 women who met inclusion criteria, 1,293 (74.7%) had no pop-offs, 240 (13.9%) had one pop-off, 128 (7.4%) had two pop-offs, and 69 (4.0%) had three or more pop-offs. Neonatal scalp/facial lacerations, intracranial hemorrhage, seizures, central nervous system depression, and neonatal intensive care unit admission were all associated with the number of pop-offs in bivariable analyses. In multivariable analyses, compared to no pop-offs, having any vacuum pop-offs was associated with an increased odds of adverse neonatal outcomes. However, there was not a consistent dose-response relationship.

CONCLUSION

While having vacuum pop-offs in a vacuum-assisted vaginal delivery was associated with an increased risk of adverse neonatal outcomes, there did not appear to be a dose-dependent association with the number of pop-offs.

KEY POINTS

· There are no specific guidelines on how many pop-offs can be allowed before abandoning a vacuum-assisted vaginal delivery.. · Having any vacuum pop-offs was associated with an increased risk of adverse neonatal outcomes.. · There was no dose-dependent association between number of pop-offs and adverse neonatal outcomes..

Secundiparas following a failed vacuum delivery-factors associated with a successful vaginal delivery: a historical prospective cohort

Background

Few studies have focused on the delivery subsequent to a failed vacuum delivery (failed-VD) in secundiparas. The objective of the current study was to examine the factors associated with a vaginal delivery following a failed-VD.

Methods

An historical prospective cohort. Obstetric characteristics of secundiparas who underwent a planned caesarean delivery (CD) were compared to those who elected a trial of labour (TOLAC) at single medical-centre, throughout 2006–2019. The latter were further analysed to study for factures associated with successful vaginal birth (VBAC).

Results

Among the 115 secundiparas included, 89 (77%) underwent TOLAC. Compared to women who underwent an elective CD, those who underwent TOLAC were younger by a mean of 4 years, were more likely to have conceived spontaneously, and had a more advanced gestation by a mean of 10 days. VBAC was achieved in 62 women (70%). New-borns of women with VBAC had in average a lower birth weight compared to those with failed TOLAC, (-)195 g ± 396 g versus ( +)197 g ± 454 g respectively, P < 0.01. Having a higher neonatal birthweight at P2 by increments of 500 g, 400 g or 300 g was associated with a failed TOLAC; OR of 9.7 (95%CI; 2.3, 40.0), 11.5 (95%CI; 2.8, 46.7) and 4.5 (95%CI; 1.4, 13.9), respectively.

Conclusions

Among secundiparas with a previous CD due to a failed-VD, the absolute difference of neonatal BW was found to be significantly associated with achieving VBAC.

Adverse outcomes in vacuum-assisted delivery after detachment of non-metal cup: a retrospective cohort study

PURPOSE

To evaluate neonatal and maternal outcomes associated with detachment of non-metal vacuum cup during delivery and to identify risk factors for these detachments.

METHODS

This retrospective cohort study included women with singleton pregnancy, who underwent vacuum-assisted vaginal delivery with a non-metal vacuum cup in a single academic institution, January 2014-August 2019. Failed vacuum deliveries were excluded. Primary outcomes were defined as subgaleal hematoma (SGH) and cord blood pH < 7.15. Secondary outcome included other neonatal complications and adverse maternal outcomes. Outcomes were compared between vacuum-assisted deliveries with and without cup detachment during the procedure.

RESULTS

A total of 3246 women had successful VAD and met the inclusion criteria. During the procedure, the cup detached at least once in 665 (20.5%) deliveries and did not detach in 2581 (79.5%). The cup detachment group experienced higher rates of SGH (8.9% vs. 3.5%, p = 0.001) and cord blood pH < 7.15 (9.8% vs. 7.1%, p = 0.03). There were also more neonatal intensive care unit admissions (NICU) (4.4% vs. 2.7%, p = 0.03) and more fetuses with occiput posterior position (70.8% vs. 79.4%, p = 0.001), the vacuum duration was slightly longer (6 ± 3.7 vs. 5 ± 2.9 min) and more neonates had birth weights > 3700 g (14.1% vs, 10.3%, p = 0.006). Interestingly, there were more males in that group (60.6 vs. 54.6, p = 0.005). All these factors remained significant after controlling for potential confounders.

CONCLUSIONS

Vacuum cup detachment has several predictive characteristics and is associated with adverse neonatal outcomes that should be incorporated into decisions made during the procedure.

Association between the number of pulls and adverse neonatal/maternal outcomes in vacuum-assisted delivery

OBJECTIVES

To determine the association between the number of pulls during vacuum-assisted deliver and neonatal and maternal complications.

METHODS

This was a single-center observational study using a cohort of pregnancies who underwent vacuum-assisted delivery from 2013 to 2020. We excluded pregnancies transitioning to cesarean section after a failed attempt at vacuum-assisted delivery. The number of pulls to deliver the neonate was categorized into 1, 2, 3, and ≥4 pulls. We used logistic regression models to investigate the association between the number of pulls and neonatal intensive care unit (NICU) admission and maternal composite outcome (severe perineal laceration, cervical laceration, transfusion, and postpartum hemorrhage ≥500 mL).

RESULTS

We extracted 480 vacuum-assisted deliveries among 7,321 vaginal deliveries. The proportion of pregnancies receiving 1, 2, 3, or ≥4 pulls were 51.9, 28.3, 10.8, and 9.0%, respectively. The crude prevalence of NICU admission with 1, 2, 3, and ≥4 pulls were 10.8, 16.2, 15.4, and 27.9%, respectively. The prevalence of NICU admission, amount of postpartum hemorrhage, and postpartum hemorrhage ≥500 mL were significantly different between the four groups. Multivariable logistic regression analysis found the prevalence of NICU admission in the ≥4 pulls group was significantly higher compared with the 1 pull group (adjusted odds ratio, 3.3; 95% confidence interval, 1.4-7.8). In contrast, maternal complications were not significantly associated with the number of pulls.

CONCLUSIONS

Vacuum-assisted delivery with four or more pulls was significantly associated with an increased risk of NICU admission. However, the number of pulls was not associated with maternal complications.

Simulation training program for vacuum application to improve technical skills in vacuum-assisted vaginal delivery

OBJECTIVE

evaluation of technical skills of the operators during the obstetrical device application for operative vaginal delivery, named kiwi-cup in a simulation training program.

METHODS

Thirty-five residents in obstetrics and gynecology of the University of Pisa, Italy were recruited and evaluated with an assessment scale on technical skills from 0 to 55 points. They performed various operative vaginal delivery simulations with kiwi-cup and were evaluated at time 0 by a tutor. After 8 weeks, simulation training was repeated and trainees were re-evaluated by the same tutor.

RESULTS

after 8 weeks from the first simulation session, trainees have been shown to increase technical skills (46.27 ± 4.6 with p-value < 0.0001), the successful application rate (85.71% with p-value 0.0161).) and to reduce the time to complete the procedure (86.2 ± 29.9 s with p-value < 0.0001).

CONCLUSION

simulation training on operational vaginal delivery significantly increases technical skills, improves successful rate, and reduces the time taken to complete the procedure.

CLINICAL TRIAL REGISTRATION

Not applicable.

Perinatal outcome after vacuum assisted delivery with digital feedback on traction force; a randomised controlled study

Background

Low and mid station vacuum assisted deliveries (VAD) are delicate manual procedures that entail a high degree of subjectivity from the operator and are associated with adverse neonatal outcome. Little has been done to improve the procedure, including the technical development, traction force and the possibility of objective documentation. We aimed to explore if a digital handle with instant haptic feedback on traction force would reduce the neonatal risk during low or mid station VAD.

Methods

A two centre, randomised superiority trial at Karolinska University Hospital, Sweden, 2016–2018. Cases were randomised bedside to either a conventional or a digital handle attached to a Bird metal cup (50 mm, 80 kPa). The digital handle measured applied force including an instant notification by vibration when high levels of traction force were predicted according to a predefined algorithm. Primary outcome was a composite of hypoxic ischaemic encephalopathy, intracranial haemorrhage, seizures, death and/or subgaleal hematoma. Three hundred eighty low and mid VAD in each group were estimated to decrease primary outcome from six to 2 %.

Results

After 2 years, an interim analyse was undertaken. Meeting the inclusion criteria, 567 vacuum extractions were randomized to the use of a digital handle (n = 296) or a conventional handle (n = 271). Primary outcome did not differ between the two groups: (2.7% digital handle vs 2.6% conventional handle). The incidence of primary outcome differed significantly between the two delivery wards (4% vs 0.9%, p < 0.05). A recalculation of power revealed that 800 cases would be needed in each group to show a decrease in primary outcome from three to 1 %. This was not feasible, and the study therefore closed.

Conclusions

The incidence of primary outcome was lower than estimated and the study was underpowered. However, the difference between the two delivery wards might reflect varying degree of experience of the technical equipment. An objective documentation of the extraction procedure is an attractive alternative in respect to safety and clinical training. To demonstrate improved safety, a multicentre study is required to reach an adequate cohort. This was beyond the scope of the study.

Trial registration

ClinicalTrials.gov NCT03071783, March 1, 2017, retrospectively registered.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-021-03604-z.