Fetal head position and perineal distension associated with the use of the BD Odon Device™ in operative vaginal birth: a simulation study

Assisted vaginal birth in 21st century: current practice and new innovations

Assisted vaginal birth rates are falling globally with rising cesarean delivery rates. Cesarean delivery is not without consequence, particularly when carried out in the second stage of labor. Cesarean delivery in the second stage is not entirely protective against pelvic floor morbidity and can lead to serious complications in a subsequent pregnancy. It should be acknowledged that the likelihood of morbidity for mother and baby associated with cesarean delivery increases with advancing labor and is greater than spontaneous vaginal birth, irrespective of the method of operative birth in the second stage of labor. In this article, we argue that assisted vaginal birth is a skilled and safe option that should always be considered and be available as an option for women who need assistance in the second stage of labor. Selecting the most appropriate mode of birth at full dilatation requires accurate clinical assessment, supported decision-making, and personalized care with consideration for the woman's preferences. Achieving vaginal birth with the primary instrument is more likely with forceps than with vacuum extraction (risk ratio, 0.58; 95% confidence interval, 0.39-0.88). Midcavity forceps are associated with a greater incidence of obstetric anal sphincter injury (odds ratio, 1.83; 95% confidence interval, 1.32-2.55) but no difference in neonatal Apgar score or umbilical artery pH. The risk for adverse outcomes is minimized when the procedure is conducted by a skilled accoucheur who selects the most appropriate instrument likely to achieve vaginal birth with the primary instrument. Anticipation of potential complications and dynamic decision-making are just as important as the technique for safe instrument use. Good communication with the woman and the birthing partner is vital and there are various recommendations on how to achieve this. There have been recent developments (such as OdonAssist) in device innovation, training, and strategies for implementation at a scale that can provide opportunities for both improved outcomes and reinvigoration of an essential skill that can save mothers' and babies' lives across the world.

Safety and efficacy of the OdonAssist inflatable device for assisted vaginal birth: the BESANCON ASSIST study

BACKGROUND

The first feasibility study of the OdonAssist inflatable device for use in clinically indicated assisted vaginal birth reported a success rate of 48% with no significant safety concerns. Additional studies exploring the device performance in other clinical settings are warranted before definitive conclusions can be drawn about its safety and efficacy in current practice.

OBJECTIVE

This study aimed to investigate the safety and efficacy of the OdonAssist before conducting a randomized controlled trial.

STUDY DESIGN

This was an open-label, nonrandomized study of 104 women with a clinically indicated assisted vaginal birth using the OdonAssist at the Besancon University Hospital, France. Data, including those of a nested cohort group of women who had an assisted vaginal birth using vacuum or spatulas because a trained OdonAssist device operator was not available at the time of delivery, were collected. The primary outcome measure was the proportion of successful assisted vaginal births using the OdonAssist. Neonatal outcome data were reviewed at days 1 and 28, and maternal outcomes were investigated up to day 90.

RESULTS

Between December 2019 and May 2021, 2191 pregnant women were approached, and 83% (1636/1973) of them consented to participate in the study. Among them, 10.7% (176/1636) required an assisted vaginal birth owing to a vertex presentation at +1 and below. The OdonAssist was used in 59% of births (104/176), and 41.1% (72/176) of the participants were included in the nested cohort group. The rate of successful assisted vaginal births using the OdonAssist was 88.5% (92/104). No emergency cesarean deliveries were performed in the OdonAssist group. There were no serious adverse maternal or neonatal reactions related to the use of the device. The rate of third- and fourth-degree perineal tears with the OdonAssist was 3.8% (4/104). The maternal perception ratings of the birth experience with the OdonAssist (collected on days 1, 7, and 28 using a 15-point scale) were high. In addition, the operators reported a positive perception of the device, with ease of use across the different steps of the procedure. One single technique was used for all vertex fetal head positions.

CONCLUSION

The OdonAssist is a safe and effective alternative to other current devices for assisted vaginal births. The high acceptance rate (83%) among pregnant women and the high rate of successful assisted vaginal births using the OdonAssist confirm the feasibility of a future randomized controlled trial.

Global, regional, and national time trends in incidence, prevalence, years lived with disability for uterine fibroids, 1990-2019: an age-period-cohort analysis for the global burden of disease 2019 study

BACKGROUND

Uterine fibroids are the most common benign neoplasm of the uterus and a major source of morbidity for women. We report an overview of trends in uterine fibroids of incidence rate, prevalence rate, years lived with disability (YLDs) rate in 204 countries and territories over the past 30 years and associations with age, period, and birth cohort.

METHODS

The incident case, incidence rate, age-standardized rate (ASR) for incidence, prevalent case, prevalence rate, ASR for prevalence, number of YLDs, YLD rate, and ASR for YLDs were derived from the Global Burden of Disease 2019 (GBD 2019) study. We utilized an age-period-cohort (APC) model to estimate overall annual percentage changes in the rate of incidence, prevalence, and YLDs (net drifts), annual percentage changes from 10 to 14 years to 65-69 years (local drifts), period and cohort relative risks (period/cohort effects) between 1990 and 2019.

RESULTS

Globally, the incident cases, prevalent cases, and the number of YLDs of uterine fibroids increased from 1990 to 2019 with the growth of 67.07%, 78.82% and 77.34%, respectively. High Socio-demographic Index (SDI) and high-middle SDI quintiles with decreasing trends (net drift < 0.0%), and increasing trends (net drift > 0.0%) were observed in middle SDI, low-middle SDI, and low SDI quintiles in annual percentage change of incidence rate, prevalence rate and YLDs rate over the past 30 years. There were 186 countries and territories that showed an increasing trend in incidence rate, 183 showed an increasing trend in prevalence rate and 174 showed an increasing trend in YLDs rate. Moreover, the effects of age on uterine fibroids increased with age and peaked at 35-44 years and then declined with advancing age. Both the period and cohort effects on uterine fibroids showed increasing trend in middle SDI, low-middle SDI and low SDI quintiles in recent 15 years and birth cohort later than 1965.

CONCLUSIONS

The global burden of uterine fibroids is becoming more serious in middle SDI, low-middle SDI and low SDI quintiles. Raising awareness of uterine fibroids, increasing medical investment and improving levels of medical care are necessary to reduce future burden.

Novel device for assisted vaginal birth: using integrated qualitative case study methodology to optimise Odon Device use within a feasibility study in a maternity unit in the Southwest of England

OBJECTIVE

When novel devices are used 'in human' for the first time, their optimal use is uncertain because clinicians only have experience from preclinical studies. This study aimed to investigate factors that might optimise use of the Odon Device for assisted vaginal birth.

DESIGN

We undertook qualitative case studies within the ASSIST Study, a feasibility study of the Odon Device. Each 'case' was defined as one use of the device and included at least one of the following: observation of the attempted assisted birth, and an interview with the obstetrician, midwife or woman. Data collection and thematic analysis ran iteratively and in parallel.

SETTING

Tertiary referral National Health Service maternity unit in the Southwest of England.

PARTICIPANTS

Women requiring a clinically indicated assisted vaginal birth.

INTERVENTION

The Odon Device, an innovative device for assisted vaginal birth.

PRIMARY AND SECONDARY OUTCOME MEASURES

Determining the optimal device technique, device design and defining clinical parameters for use.

RESULTS

Thirty-nine cases involving an attempted Odon-assisted birth were included in this study, of which 19 resulted in a successful birth with the device. Factors that improved use included optimisation of device technique, device design and clinical parameters for use. Technique adaptations included: applying the device during, rather than between, contractions; having a flexible approach to the application angle; and deflating the air cuff sooner than originally proposed. Three design modifications were proposed involving the deflation button and sleeve. Although use of the device was found to be appropriate in all fetal positions, it was considered contraindicated when the fetal station was at the ischial spines.

CONCLUSIONS

Case study methodology facilitated the acquisition of rapid insights into device function in clinical practice, providing key insights regarding use, design and key clinical parameters for success. This methodology should be considered whenever innovative devices are introduced into clinical practice.

TRIAL REGISTRATION NUMBER

ISRCTN10203171.

Women's experiences of the Odon Device to assist vaginal birth and participation in intrapartum research: a qualitative study in a maternity unit in the Southwest of England

OBJECTIVE

To investigate women's experiences of having a birth assisted by the Odon Device (an innovative device for assisted vaginal birth) and participation in intrapartum research.

DESIGN

Qualitative semistructured interviews and observations undertaken in the context of case study work embedded in the ASSIST feasibility study.

SETTING

A tertiary referral National Health Service (NHS) maternity unit in the Southwest of England, between 8 October 2018 and 26 January 2019.

PARTICIPANTS

Eight women, four operators and 11 midwives participated with eight observations of the assisted vaginal birth, eight interviews with women in the postnatal period, 39 interviews/reflections with operators and 19 interviews with midwives. Women in the case study research were recruited from participants in the main ASSIST Study.

INTERVENTION

The Odon Device, an innovative device for assisted vaginal birth.

RESULTS

Thirty-nine case studies were undertaken. Triangulation of data sources (participant observation, interviews with women, operators and midwives) enabled the exploration of women's experiences of the Odon Device and recruitment in the intrapartum trial. Experiences were overwhelmingly positive. Women were motivated to take part by a wish for a kinder birth, and because they perceived both the recruitment and research processes (including observation) to be highly acceptable, regardless of whether the Odon-assisted birth was successful or not.

CONCLUSIONS

Interviews and observations from multiple stakeholders enabled insight into women's experiences of an innovative device for assisted vaginal birth. Applying these qualitative methods more broadly may illuminate perspectives of key stakeholders in future intrapartum intervention research and beyond.

TRIAL REGISTRATION NUMBER

ISRCTN10203171; ASSIST Study registration; https://doi.org/10.1186/ISRCTN10203171.

Outcomes of the novel Odon Device in indicated operative vaginal birth

BACKGROUND

No new method of assisting vaginal birth has been introduced into clinical practice since the development of the vacuum extractor in the 1950s. The Odon Device is a new device that employs a circumferential air cuff over the fetal head to assist birth. In this study, the Odon Device has been used to assist vaginal birth for standard clinical indications.

OBJECTIVE

This study aimed to investigate the clinical impact, safety, and acceptability of the Odon Device to women, their babies, and clinicians and to assess the feasibility of recruiting women to an interventional intrapartum research study.

STUDY DESIGN

This is a nonrandomized, single-arm interventional feasibility study of the Odon Device for operative vaginal birth undertaken in a single maternity unit: Southmead Hospital, Bristol, United Kingdom. The Odon Device was used to assist birth in 40 women who required the birth to be assisted for suspected fetal compromise and/or prolonged second stage of labor. The primary clinical outcome was the proportion of births successfully assisted with the Odon Device, and the primary feasibility outcome was the proportion of eligible women who were approached and who agreed to participate. Neonatal outcome data were reviewed at day 28, and maternal outcomes were investigated up to day 90.

RESULTS

Between October 2018 and January 2019, 298 of 384 approached, eligible women (77.6%) consented to participate. Of these women, 40 received the intervention-the use of the Odon Device. Birth was assisted in all cephalic (occiput anterior, occiput transverse, and occiput posterior) fetal positions, at all stations at or below the ischial spine and with or without regional analgesia. The Odon Device was effective in 19 of 40 cases (48%). Of the 40 births, 21 (52.5%) required additional assistance: 18 of 40 births (45%) were completed using nonrotational forceps, 1 of 40 births (3%) required rotational forceps, and 2 of 40 births (5%) required an emergency cesarean delivery. There was no serious maternal or neonatal adverse event related to the use of the device, and there was no serious adverse device effect. There were 4 devices (10%) that were ineffective because of a manufacturing fault. Furthermore, 39 of 40 women (98%) reported a high birth perception score. All practitioners were able to use the device as intended, although some steps in using the device were reported to be easier to perform (setup and deflation of air chamber) than others (application of the device and withdrawal of the applicator).

CONCLUSION

Recruitment to an interventional study of a new device for operative vaginal birth was feasible; 78% of eligible women were willing to participate, often expressing an aspiration for an alternative to forceps and vacuum. The success rate of the Odon Device was lower than reported success rates of vacuum and forceps; however, in this study, the device had been used to assist birth for standard clinical indications. There was no significant maternal or neonatal safety concern associated with the use of the device, although the number of births studied was small. Further feasibility study to establish iterative changes to the device, technique, and clinical indications is necessary.

The Odon Device™ for assisted vaginal birth: a feasibility study to investigate safety and efficacy-The ASSIST II study

BACKGROUND

The Odon Device™ is a new device for assisted vaginal birth that employs an air cuff around the fetal head for traction. Assisted vaginal birth (AVB) is a vital health intervention that can result in better outcomes for mothers and their babies when complications arise in the second stage of labour. Unfortunately, instruments for AVB (forceps and ventouse) are often not used in settings where there is most clinical need often due to lack of training and resources, resulting in maternal and neonatal morbidity and mortality which could have been prevented. This is often due to a lack of trained operators as well as difficulties in the sterilisation and maintenance of AVB devices. This novel, single use device has the potential to mitigate these difficulties as it is single use and is potentially simpler to use than forceps and ventouse. All the studies of the Odon Device to date (pre-clinical, preliminary developmental and clinical) suggest that the Odon Device does not present a higher risk to mothers or babies compared to current standard care, and recruitment to intrapartum research exploring the device is feasible and acceptable to women. The first study in which the Odon Device was used in clinically indicated conditions (the ASSIST Study) reported a lower efficacy than those reported with established devices. The reasons need to be explored, specifically focussing on learning curve, the technique of the doctors using this new device and potential modifications to device design. A follow-on clinical study to further investigate the efficacy and safety of the Odon Device in its indicated use, the ASSIST II Study, is therefore being undertaken.

METHODS

The primary feasibility outcome is study feasibility (recruitment and retention rates) whilst the primary clinical outcome successful vaginal birth completed with the Odon Device. Key secondary feasibility outcomes include participant withdrawal, compliance in data collection and acceptability of the device to women and operators. Secondary clinical outcomes include maternal, neonatal and device outcomes. Safety data will be reviewed following every birth exploring maternal, neonatal and device risks. Using A'Hern approach for sample size calculation, we aim to recruit 104 women requiring an assisted vaginal birth for a recognised clinical indication. Assuming an AVB success rate of 65% or more, a one-sided alpha risk of 5% and power of 90%.

DISCUSSION

The data from the ASSIST II Study will provide the information required regarding acceptability, recruitment, outcome data collection, device design, technique of device use and operator learning curve in order to design a future randomised controlled trial of the Odon Device versus current modes of assisted vaginal birth.

TRIAL REGISTRATION

ISRCTN registration: 38829082 (prospectively registered July 26, 2019).

The BD Odon Device™: an update of its current state

The BD Odon Device™ was designed as an alternative to conventional methods for assisting vaginal delivery, especially in low-resource settings. This a systematic review of published data concerning the BD Odon Device™ until March 2020 listed in Pubmed, Google Scholar, SCOPUS and Web of Science.Five studies testing the device were found, three in models and two in women with uncomplicated deliveries. According to their results, the device seems easy to use, safe, effective and requires simple and fast training, so it may become a good alternative to vacuum extractor or forceps, especially in places where there is less specialised staff, low-resources settings. The study protocol of the first study in complicated second stages has already been published. There is still few information about the BD Odon Device™ in scientific literature, however more research concerning the device is expected to take place in a near future.Impact StatementWhat is already known on this subject? The Odon Device^TM is a device under development that aims to be a useful tool to assist vaginal deliveries.What do the results of this study add? This is a review of the current state of the development of the Odon Device^TM. Further tests in humans are planned in the future in order to evaluate its safety and efficacy.What are the implications of these findings for clinical practice and/or further research? The Odon Device^TM may be a promising tool to assist vaginal deliveries, especially in low-resource countries and countries with high rates of C-section during second stage of labour, but further research is needed to evaluate its safety and efficacy.

Simulation for intrapartum care: from training to novel device innovation

Improving maternal and perinatal care is a global priority. Simulation training and novel applications of simulation for intrapartum care may help to reduce preventable deaths worldwide. Evaluation studies have published details of the effectiveness of simulation training for obstetric emergencies, exploring clinical and non-clinical factors as well as the impact on patient outcomes (both maternal and neonatal). This review summarized the many uses of simulation in obstetric emergencies from training to assessment. It also described the adaption of training in low-resource settings and the evidence behind the equipment recommended to support simulation training. The review also discussed novel applications for simulation such as its use in the development of a new device for assisted vaginal birth and its potential role in Cesarean section training. This study analyzed the financial implications of simulation training and how this may impact the delivery of such training packages, considering that simulation should be developed and utilized as a key tool in the development of safe intrapartum care in both emergency and non-emergency settings, in innovation and product development.

[Focus on the Odon Device™: Technical improvements, mechanical principles and progress of the clinical research program]

The Odon Device™ has been described in the literature since 2013 and the World Health Organization supports its development through the Human Reproduction Program. This innovative device could be easier to use than usual instruments and could be an alternative to caesarean section during the second stage of labor, especially in countries where access to obstetric care is limited. The aim of the Odon Device™ is to position an air cuff over the fetal head, past its widest point (around the level of the fetal mouth anteriorly and the nape of the fetal neck posteriorly). Three mechanical principles favor the progression of the fetal head with the Odon Device™: partial propulsion, limited flexion and traction. Preliminary clinical studies on animals and simulators are reassuring and show that an appropriate use is no more at risk than the vaccum or forceps. A phase 1 study was conducted in Argentina and South Africa between 2011 and 2017. The reported failure rate was 29%, of which 77% was secondary to a mechanical failure of one of the components of the device. Improvements concerning the applicator, the handles and the inflatable air cuff have been made to the device. Phase II of the clinical research program began in 2018 and includes two studies in two different centers: The ASSIST Study in Bristol, England, and The BESANCON ASSIST Study, Besançon, France.

The ASSIST Study - The BD Odon Device for assisted vaginal birth: a safety and feasibility study

BACKGROUND

Assisted vaginal birth is a vital health intervention that can result in better outcomes for mothers and their babies when complications arise in the second stage of labour. Unfortunately, instruments for assisted vaginal birth (forceps and ventouse) are often not utilised in settings where there is most clinical need, resulting in maternal and neonatal morbidity and mortality which could have been prevented. The BD Odon Device is a new device for assisted vaginal birth that may be able to address this unmet need. However, before dissemination, the device requires evaluation in robust clinical trials. A feasibility study to investigate the clinical impact, safety, and acceptability of the BD Odon Device for assisted vaginal birth is therefore planned. This will provide further information on acceptability, recruitment, and the outcome data required to design a future randomised controlled trial of the BD Odon Device versus Kiwi ventouse.

METHODS

Forty women who require an assisted vaginal birth for a recognised clinical indication will have the birth assisted with the BD Odon Device. The primary outcome is successful vaginal birth completed with the BD Odon Device. Secondary clinical outcomes include maternal and neonatal outcomes, and maternal and practitioner satisfaction. Safety data will be reviewed following every birth.

DISCUSSION

A future randomised controlled trial of the BD Odon Device versus the current standard instrument (the Kiwi ventouse) is planned. The findings of the ASSIST Study will inform the randomised controlled trial design.

TRIAL REGISTRATION

ISRCTN, ISRCTN10203171 . Prospectively registered on 27 July 2018.

Odon device for instrumental vaginal deliveries: results of a medical device pilot clinical study

Background

A prolonged and complicated second stage of labour is associated with serious perinatal complications. The Odon device is an innovation intended to perform instrumental vaginal delivery presently under development. We present an evaluation of the feasibility and safety of delivery with early prototypes of this device from an early terminated clinical study.

Methods

Hospital-based, multi-phased, open-label, pilot clinical study with no control group in tertiary hospitals in Argentina and South Africa. Multiparous and nulliparous women, with uncomplicated singleton pregnancies, were enrolled during the third trimester of pregnancy. Delivery with Odon device was attempted under non-emergency conditions during the second stage of labour. The feasibility outcome was delivery with the Odon device defined as successful expulsion of the fetal head after one-time application of the device.

Results

Of the 49 women enrolled, the Odon device was inserted successfully in 46 (93%), and successful Odon device delivery as defined above was achieved in 35 (71%) women. Vaginal, first and second degree perineal tears occurred in 29 (59%) women. Four women had cervical tears. No third or fourth degree perineal tears were observed. All neonates were born alive and vigorous. No adverse maternal or infant outcomes were observed at 6-weeks follow-up for all dyads, and at 1 year for the first 30 dyads.

Conclusions

Delivery using the Odon device is feasible. Observed genital tears could be due to the device or the process of delivery and assessment bias. Evaluating the effectiveness and safety of the further developed prototype of the BD Odon Device™ will require a randomized-controlled trial.

Trial registration

ANZCTR ACTRN12613000141741 Registered 06 February 2013. Retrospectively registered.