ASSIST Ethiopia: Feasibility Clinical Investigation of the Odonassist™ Medical Device

INTRODUCTION

The OdonAssist™ inflatable device for assisted vaginal birth (AVB), is a frugal innovation from the southern hemisphere and an unconventional environment as it was invented by an Argentinian car mechanic, Jorge Odon. The device has been developed with the intention to be safe, easy to use and more acceptable than currently used AVB devices (forceps and vacuum extractor) because of its innovative mechanism of action. Its potential for improving maternal and neonatal health is now recognized based on the results of three clinical trials conducted in France and UK.

The investigation proposal is to conduct a feasibility study of OdonAssistTM at Saint Luke's Hospital in Wolisso, Ethiopia, to determine the feasibility of using the OdonAssistTM in a low-income country and assess its acceptability in those settings. In addition, with a view to researching the efficiency and budgetary impact of this innovation, data will be collected on its cost and effectiveness, for comparison with reference interventions at local level (vacuum extractor and emergency second stage caesarean section).

Improving the health of mothers and newborns is among the main priorities of the Ethiopian Health Sector Strategic Plan (HSDP IV). The 2016 Ethiopian Demographic and Health Survey preliminary report indicated that Ethiopia has made good progress in reducing neonatal, infant and under five mortalities reporting respectively 29, 48 and 67 deaths per 1,000 live births in years 0-4 prior to the survey, while these figures were 47, 78 and 116 deaths per 1,000 live births 10-14 years prior to the survey. However, the neonatal mortality rate has not declined significantly, nor has the infant and under-five mortality rate and the maternal mortality rate, which is still high at 557 maternal deaths per 100,000 live births caused by pregnancy-related complications (https://data.worldbank.org/indicator/SH.STA.MMRT.NE).

Complications in childbirth are a major cause of maternal and infant mortality and morbidity, accounting for 4-13% of maternal deaths and 25% of neonatal deaths worldwide. Approximately 10-15% of the 134,000,000 births worldwide each year require assistance with forceps or vacuum extractor or emergency caesarean section at full cervical dilation to avoid serious maternal and neonatal complications. In Ethiopia, it is estimated that 12% of pregnant women have a complicated labor, which, according to published studies, causes between 17% and 36% of maternal deaths, 24% of neonatal deaths, 36% of stillbirths and high rates of obstetric fistulas.

The Ethiopian government has made improving maternal and neonatal health a national priority and has identified limited access to AVB as an obstacle to be overcome. The use of innovations has been advocated as a solution to increase access to medical care. These government policies, aimed at improving maternal and newborn health, will be conducive to future efforts to scale up OdonAssistTM in Ethiopia. In addition, the International Federation of Gynecology and Obstetrics (FIGO), which issues globally adopted medical guidelines, has expressed in an official letter its interest in supporting the adoption of OdonAssistTM globally.

PROBLEM STATEMENT AND SIGNIFICANCE OF THE STUDY

Prolonged and complicated labor is a major cause of maternal and neonatal mortality and long-term morbidity. Prolonged or complicated second stage of labor requiring an AVB with forceps or vacuum extractor, or an emergency caesarean section (CS) occurs in approximately 10-15% of births and contributes to 4-13% of all maternal deaths. AVB can be safer than an emergency CS in the short and long term for mothers and babies. AVB is associated with a reduced risk of maternal hemorrhage, intrapartum stillbirth, admission to intensive care for newborns, abnormally invasive placenta (a life-threatening condition for the mother), stillbirth and preterm birth in subsequent pregnancies; AVB is also more cost effective than a cesarean section. The current options for AVB, forceps and vacuum extractor, require time and practice to acquire sufficient skills for use and, if performed inappropriately, can be associated with significant trauma to both mothers and babies. Insufficient training, limited availability of functioning devices, and pervasive concerns about complications are supply side factors that have all reduced access to AVB, particularly in low and middle income countries where there is the most potential benefit (given the growing concentration of maternal & perinatal mortality, as well as the increasing proportion of births, in these settings). Although the World Health OrganisationTM lists AVB as a vital function for all basic emergency obstetric care facilities, African countries commonly report AVB as the least available of these functions. In sub-Saharan African countries, AVB rate is approximately 1% as compared to up to 16% in Western Europe.21 Women living in low resource settings who experience prolonged labor are either: left untreated with dire consequences, or referred for an emergency CS with additional risks associated with the requirement for transfer, the potentially less safe/more invasive surgery and the anesthesia required for laparotomy.29 The OdonAssist™ is an innovation that, because of its innovative simple and potentially less traumatic mechanism of action, is designed to improve women's access to AVB by overcoming the entrenched obstacles and barriers that limit its use with the presently available options of forceps and vacuum extractor.

The mechanism of the OdonAssist is based on inflating an air chamber around the fetal head to act as an anchor point, allowing the practitioner to apply traction. The positive safety profile, as observed in the clinical trials conducted so far, will also reduce the concerns with potential maternal and newborn complications presently associated with AVB. We envisage that, with appropriate but less demanding training than for forceps and vacuum, this device could be used by both doctors and midlevel providers such as midwives when allowed by local laws, health policies and guidelines. In addition, the device is single use and provided sterile and ready to use, thereby eliminating the need to ensure maintenance and functionality.

Given these considerations, the specific aim of the proposed study is to assess the feasibility of the OdonAssist in Ethiopia by collecting preliminary data on efficacy rate, safety profile and acceptability to women and health workers and relate them to the outcomes of AVB with vacuum extractor or cesarean section in the second stage of labor. In addition, data will be collected to inform a future evaluation of the cost utility of the OdonAssist in relation to vacuum and second stage cesarean section.

THE ODONASSIST(TM)

An innovative mechanism of action Because of its innovative mechanism of action, the OdonAssistTM is intended to represent an advance in obstetrics which could enhance the safety of AVB and reduce the training requirements. Differently from the forceps and vacuum extractors, the OdonAssistTM mechanism of action works by inflating an air chamber circumferentially around the fetal head to evenly distribute the pressure needed to establish the anchor point for traction. By using a more flexible and softer anchor point, the pressure is evenly distributed 360 degrees around the fetal head. This mechanism represents a potential advantage relative to the focalized pressure applied by the rigid metal blades of the forceps. The lack of need for negative pressure is expected to reduce the risk of both mild and serious negative-pressure related adverse events associated with vacuum extractors, such as subgaleal hemorrhage. Notably, no typical device related pattern of neonatal superficial injury was observed with the OdonAssist in clinical trials, in contrast to the well-known typical effects seen with the use of forceps (e.g. facial marks) and vacuum extractor (e.g. caput succedaneum and circular bruising). The absence of superficial signs and marks on the baby's head and face associated with the use of AVB devices was appreciated by women and health professionals involved in the clinical studies of OdonAssistTM who reported this differentiating characteristic of OdonAssistTM as one of the reasons to prefer it over forceps.

In addition, the mechanism of action and softness of materials of the OdonAssistTM is likely to cause less pain for the newborn than other AVB devices. Fetal pain receptors and nerve tracts are developed by 20-24 weeks gestation in quantities similar to those found in adults, therefore newborns experience pain which can be assessed using validated pain scales such as the EDIN (Échelle de Douleur Inconfort Nouveau-Née, Neonatal Pain and Discomfort Scale) and the NIPS (Neonatal Infant Pain Scale). AVB with vacuum extractor has been associated with a proportion of EDIN scores indicative of pain (39%) much higher than the levels below 5% reported in the safety and efficacy clinical studies of OdonAssist.

Another important difference and potential advantage of OdonAssist over currently used AVB devices is that the application of OdonAssist is not dependent on the position (occipito-anterior, occipito-transverse and occipito-posterior) of the fetal occiput in the birth canal. The OdonAssist device can be used in all possible occiput positions, therefore increasing ease of use, and minimizing the risk of misapplication. During the clinical trials of the OdonAssist, this characteristic prevented the risk of harming the woman and/or the baby because of incorrect application of the device.

Clinical evidence In the clinical studies conducted until now with the OdonAssistTM, there were no severe adverse events causally related to the device, no serious device-related adverse reactions and no serious adverse device effects. In addition, results emerging from the clinical studies are indicative of high maternal and operator satisfaction and acceptability. Operators found the device easy to use for several reasons including the fact that the same application technique is used for all fetal positions meaning there is no risk of incorrectly positioning the device in relation to vulnerable fetal or maternal anatomies. Satisfaction of mothers regarding the use of the device was very high, as women wanted an alternative device for AVB and were keen for a 'kinder' AVB. The observed effectiveness rate of the device improved progressively over time, increasing in each subsequent study and reaching levels of effectiveness consistent with the range of values for AVB reported in the scientific literature.

STUDY OBJECTIVES

The objectives of the study are:

• To assess the feasibility of the OdonAssist (new intervention) in terms of preliminary data on safety, efficacy, acceptability at the hospital Saint Luke's in Ethiopia and relate them to the performance of vacuum extractor and second stage cesarean section (reference interventions).
• To perform a cost analysis of the OdonAssist (new intervention) at the hospital Saint Luke's in Ethiopia in comparison with vacuum extractor and second stage Cesarean section (reference interventions).

Inclusion criteria

Women will be able to participate in the ASSIST Ethiopia Study if all of the following apply at initial consent:

• ≥18 years of age;
• singleton pregnancy of at least 36 weeks' gestation,
• negative antenatal screen for HIV and Hepatitis B,
• in active labour and requiring an assisted vaginal birth for a clinical indication (as per local guidelines),
• the vertex is 1 cm or more below the ischial spines and there is no obstetric indication for an alternative method of AVB.

Exclusion criteria

Women will not be able to take part in the ASSIST Ethiopia Study if:

• the fetal vertex is at or above the ischial spines,
• there is a diagnosis of a fetal skull abnormality (i.e. macrocephaly) or osteogenesis imperfecta,
• there is a suspicion of a fetal bleeding disorder (von Willebrand's disease, AITP, haemophilia),
• there is an intrauterine fetal death in the current pregnancy,
• the woman is sensitive to latex,
• the woman is currently serving a prison sentence,
• there is a fetal bradycardia which is on-going and has not recovered.