The ASSIST Study is exploring the safety and effectiveness of a new device for assisted birth, called the BD Odon Device.


Instead of using suction or forceps, the BD Odon Device has an inflatable air cuff that is placed on the baby’s head to assist birth. The device has undergone rigorous testing in both simulation and in births.

What is the purpose of the ASSIST Study?

The BD Odon Device is a new, single-use instrument that can assist the birth of babies, using an inflatable air cuff. We wish to compare the BD Odon Device with the ventouse (suction cup) or forceps, which are devices that are routinely used to assist birth. We would like to find out which device is best for women and babies. In the first phase of the study, if a woman needs assistance to give birth and has agreed to participate in the study, then she will have this performed using the BD Odon Device instead of a ventouse or forceps.

What do we know about the safety of the BD Odon Device?

The BD Odon Device has been designed by a team to midwives, doctors and engineers to be as safe as possible. During development, the BD Odon Device has undergone rigorous testing in both simulation and for a small number of births.

Why may I be invited to take part?

All women who are pregnant with one baby (not twins) and are planning for a vaginal birth at North Bristol NHS Trust are being invited to take part in this study. Only a small number of women in labour will require an assisted vaginal birth, and at Southmead hospital this is approximately one in 8 women.

Further Information?

If you would like to hear more about the study, please let your midwife or doctor know when you next come to the hospital, or tell your community midwife at your next appointment. We will be able to talk to you in detail and give you more information from when you are 28 weeks pregnant. Alternatively, you can email us on or telephone: 0117 414 6764

More information is available in our ASSIST Study Participant Information Leaflet and Video, and also from the research midwives and doctors.