Maternity nurse with patient & baby

Women & Children's Completed Research

The Women and Children’s Research Unit conducts research that aims to improve the care of women and children using Obstetrics and Gynaecology services. This includes pre-conception services though to postnatal care.

The Unit collaborates widely with other disciplines and professions, as well as with women and their companions, to develop ground-breaking research and care, for our patients and throughout the NHS.

Please speak to the person treating you to find out if there is a research study that may be able to help you.

Completed Studies:


Around one in eight women in the UK require assistance to give birth to their baby vaginally. Currently, doctors use either forceps or a ventouse (a suction cup) to help women have their babies in this manner. This is known as an assisted vaginal birth (AVB). Most mothers and babies do very well after an AVB, and the procedure is usually much better for both mothers and babies than the alternative, an emergency Caesarean section.

However, women and their babies can sometimes be harmed by an AVB. Mothers have a greater tendency to have severe tears of the vagina, and, sometimes, the rectum (back passage) compared to a spontaneous vaginal birth. Mothers may have more pain while healing (usually for one to two weeks) following a birth that has been assisted by forceps or ventouse. Babies may develop bruising over the scalp or face where the forceps or ventouse have been applied. Babies can also, very rarely (around 1 in 1000), sustain more serious harm, such as nerve injuries or bleeding into the brain or eye. Therefore, although AVB is generally very safe and usually better than the alternative (an emergency caesarean section), it is sensible to try to improve the technique to assist a vaginal birth and reduce the risks to both mothers and their babies., No new types of devices to assist vaginal birth have been introduced into practice since the ventouse in the 1950s.

The BD Odon Device is a new device for AVB that has been designed by a team of midwives, doctors and engineers. The BD Odon Device works by placing a cuff of air which is attached to a sleeve, around the baby’s head. The doctor then gently pulls on this sleeve and air cuff to assist the birth of the baby.

In this study, we used the BD Odon Device to help women give birth in cases where it is necessary to assist the birth of the baby. Our study evaluated the safety and effectiveness of the BD Odon device and sought the views of women and healthcare professionals on its use. The information gained from the study has since been used for the large comparative study, ASSIST II.

Project Details
Principal Investigator: Jo Crofts
Study Completion: TBC
Local Ref: TBC


The ASSIST II Study was available to women who planned to have a vaginal birth at Southmead or Cossham Maternity Units and who may have required help assisting the birth of their baby vaginally during the final stages of labour. The study used a novel alternative device to the forceps or suction cup called the Odon Device. The Odon Device uses a soft inflated cuff of air around the baby’s head to help move the baby down the birth canal.

After a 3-month period of follow-up assessments, the study will complete data collection in September 2021.

The ASSIST II Study team aim to publish the results of this research in 2022 and will share the findings with previous participants and members of the public via this website.

Thank you to everyone who has expressed an interest in ASSIST II, to the 900 women who consented to take part, and to the 126 women who allowed us to support their births and follow their postnatal journeys.

To find out more about ASSIST II, please contact the study team via

Project Details
Principal Investigator: Jo Crofts
Study Completion: TBC
Local Ref: TBC

IMOX Study

The IMOX study is a multi-centre, double blinded, randomised controlled trial which is comparing the three medicines used for the active management of the third stage of labour.

The third stage of labour is the period of time between the birth of the baby and the delivery of the placenta. There are two ways of managing the third stage of labour, and this study applies to women who are choosing to have an active management of the third stage of labour, following a vaginal birth. Active management involves a one-off injection of a medicine which is designed to help keep the womb contracted thus reducing the risk of a post-partum haemorrhage.

The purpose of the study was to find out which of the 3 medicines, that are currently in use, is the most effective and which allows women to feel as well as possible in the first few hours after their birth.

The study was completed in July 2018. The results are in the process of publication.

Project Details
Principal Investigator: TBC
Study Completion: TBC
Local Ref: TBC


The aim of the PARENTS Study was to evaluate how parental engagement in Perinatal (Stillbirth and Neonatal) death hospital reviews could work in practice and to establish a ‘gold-standard’ for this process that could support this parental engagement across the NHS (and internationally).

In the UK, more than 5,000 babies die before or shortly after birth each year. This can result in a wide range of negative outcomes for parents, families and healthcare staff. 

Parents are rarely involved in the perinatal death hospital review process that takes place after the death of a baby (the Perinatal Mortality Review or “PNMR) and many are largely unaware that it even takes place. However, engaging parents in this process can help them deal with their grief more effectively. Their unique perspective also has the potential to improve care, going forward, by highlighting good practice and areas for improvement.  

The PARENTS Study actively involved parents in the perinatal death review process at NBT’s Southmead Hospital. Involving parents in such a sensitive area is a genuinely novel, yet urgently needed and recommended approach.

The Study was led by our Consultant Senior Clinical Lecturer, Christy Burden, hosted by North Bristol NHS Trust, funded by the Health Foundation and supported by Sands Stillbirth and Neonatal death charity.

PARENTS Study Results:

The impact on patient care was assessed using questionnaires and focus group discussions. The views and experiences of parents, staff and stakeholders was considered to enable the development of a standardised process that is sustainable, useful and has a positive impact on patient care and improve longer term outcomes following bereavement. Approaches such as ours are also helping to promote further transparency and an open culture within the NHS.

The lessons learnt allowed the team to develop a ‘gold-standard’ for engaging bereaved parents in the PNMR following their baby’s death. This gold-standard can be followed using the resources produced as part of the study which are under NBT copyright. To request a copy of the summary and results, please email

This improved and innovative review process, that now gives parents the opportunity to be engaged, has been adopted as part of the Perinatal Mortality Review Tool (PMRT), that is being implemented nationally by our collaborators at the National Perinatal Epidemiology Unit (NPEU) at the University of Oxford.

We want MPs and commissioners to invest in parental engagement. Our vision is to have the option for parental involvement mandated in every hospital and properly resourced.

Project Details
Principal Investigator: TBC
Study Completion: TBC
Local Ref: TBC

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About Research & Innovation

NBT Researcher

Find out more about our research and how we're working to improve patient care.

Contact Research & Innovation

Research & Innovation
North Bristol NHS Trust
Floor 3, Learning & Research Centre
Southmead Hospital
Bristol, BS10 5NB

Telephone: 0117 4149330