NHS England is rolling out a national alert system across all maternity services in England to identify emerging safety concerns more quickly and prompt action.
The Maternity Outcomes Signal System (MOSS) scans routinely collected maternity data in near real time for unusual patterns or trends that could indicate a developing safety problem. When the system detects a statistically significant change, it issues a signal that requires the affected maternity unit to carry out an urgent safety check and report actions to regional and national teams within eight working days.
Signals are colour coded: amber alerts reflect about 95% confidence that an increase is real and merits attention, while red alerts indicate roughly 99% confidence and need immediate response. MOSS runs every day of the week and makes data and signals visible at trust, Integrated Care Board (ICB), regional and national levels so concerns can be seen from ward to boardroom. National leaders have told hospital executives to raise any MOSS-identified issues at public board meetings.
Retrospective reviews suggest MOSS would have flagged concerns in units that later experienced serious incidents, including East Kent, Shrewsbury & Telford, Leeds and Nottingham. The system is intended to strengthen a positive safety culture in maternity services, encouraging staff to identify and address problems openly and quickly.
Duncan Burton, Chief Nursing Officer for England, said MOSS will help spot early warning signs and avert harm by enabling faster intervention. He stressed that maternity teams and hospital leaders must act promptly on warnings so problems are not overlooked or delayed.
Cambridge University Hospitals NHS Foundation Trust was an early pilot site. Cathy Bevens, lead safety and governance midwife there, said the system has helped teams feel more responsive: it focuses attention on specific issues, brings staff and leaders together, and fosters trust by listening to women’s experiences on the labour ward.
MOSS was developed after the Reading the Signals report, which followed the independent inquiry into East Kent maternity and neonatal services led by Dr Bill Kirkup. An expert group that shaped MOSS included Dr Kirkup, Professor David Spiegelhalter, families and service users. Dr Kirkup described the tool as a positive outcome of the investigation and credited families who raised concerns.
Service user representative Chris Binnie, whose son was stillborn in 2014 from undetected growth restriction, said the system promotes a “culture of curiosity” that supports learning and could prevent avoidable stillbirths and neonatal deaths.
The statistical method behind MOSS is the cumulative sum control chart (CUSUM) approach, already used in children’s cardiac and paediatric intensive care services. CUSUM is designed to detect trends in rare but serious events, allowing earlier investigation and action, and MOSS focuses particularly on intrapartum care safety.
Health and Social Care Secretary Wes Streeting described the rollout as a key step to improve maternity care, noting every signal will be visible from bedside to boardroom and investigated. He also announced a maternity and neonatal taskforce and a rapid national investigation process to support sustained improvements.
The launch of MOSS is part of wider NHS efforts to strengthen maternity and neonatal services, including programmes such as the Perinatal Equity and Anti-Discrimination Programme, and reflects a drive to ensure safety issues are detected early and acted on consistently across the country.
