Diagnostic accuracy of handheld ultrasound, performed in community and hospital settings at 36 weeks to determine fetal presentation: the Sono-breech study protocol.

INTRODUCTION: Around 4% of babies are in breech presentation at the end of pregnancy but up to 43% of these are missed by abdominal palpation alone. Since women in the UK without additional risk factors do not routinely receive a scan in the third trimester, around 1%-2% of women present with undiagnosed breech presentation in labour, which is associated with poorer outcomes for both mothers and babies. Research suggests a point-of-care ultrasound (PoCUS) scan in late pregnancy could improve the rate of breech presentation detection. The Sono-breech study aims to determine the diagnostic accuracy and acceptability of handheld scans performed by midwives for fetal presentation at 36 weeks and how cost-effective this would be to implement in routine antenatal care in the National Health Service (NHS). METHODS AND ANALYSIS: Prior to delivering the study, midwives receive training for the detection of presentation and fetal heart rate using handheld ultrasound equipment.The study will take place in at least 10 NHS Trusts across England selected to ensure a diverse participant population and to include under-researched settings. Between 35+0 and 36+6 weeks' gestation, women who consent to the study will receive a scan for fetal presentation performed by a midwife using a handheld PoCUS device alongside routine antenatal checks, including palpation. Before the end of the next day, they will receive a conventional ultrasound scan performed by a practitioner deemed already competent at obstetric scanning. This scan will be considered the gold standard for presentation. All results will be recorded in the Sono-breech REDCap database. Women with babies in non-cephalic presentations will be referred to their local NHS Trust pathway for further management. Diagnostic accuracy (sensitivity and specificity) will be computed from the comparison between findings at the midwife-performed scan and the conventional ultrasound scan.Birth outcome data will be collected from the participants' medical notes after they have given birth. Aggregate birth data regarding the rate of undiagnosed non-cephalic births will be collected from all women who deliver at each site.Midwives who take part in the study will be invited to participate in focus groups or interviews about the implementation of the scan into routine care. Non-participant observation will take place during midwife training sessions and antenatal clinics in specific participating trusts.6-12 weeks after birth, some women will be invited to take part in an interview to explore their experience with the handheld scan.6 weeks after birth, all women will be sent two questionnaires by email. These questionnaires will be used in combination with the birth outcome data and NHS tariffs to calculate the cost-effectiveness of introducing the handheld scan into routine antenatal care in the NHS.Study registration ISRCTN11748052. ETHICS AND DISSEMINATION: The study has obtained approval from the West Midlands-South Birmingham Research Ethics Committee and was approved by the Health Research Authority and Health and Care Research Wales. Publication will be in line with the National Institute of Health and Care Research (NIHR) Open Access policy.