Mothers and babies in England are set to benefit from safer care as the NHS rolls out a pioneering safety signal system across maternity services nationwide.
The Maternity Outcomes Signal System (MOSS) is a first-of-its-kind tool designed to rapidly analyse routinely recorded data from maternity wards. Its purpose? To detect emerging safety concerns early—before they escalate into serious incidents.
If MOSS identifies unusual patterns or trends in the data, it issues an alert prompting an urgent safety review within the affected unit. Once a signal is generated, maternity teams must complete a critical safety check within eight working days and share their actions with regional and national teams.
Signals are colour-coded for clarity:
- Amber alerts indicate a 95% confidence level that an increase in events is real.
- Red alerts represent a 99% confidence level, requiring immediate attention.
This robust online system will operate seven days a week across all NHS maternity services. Retrospective analysis suggests MOSS could have flagged early warning signs in units later linked to serious incidents, including East Kent, Shrewsbury & Telford, Leeds, and Nottingham.
Data and alerts will be visible at every level—trust, Integrated Care Board (ICB), regional, and national—ensuring transparency and rapid action from ward to boardroom. NHS leaders have instructed hospital executives to raise any MOSS-identified safety issues at public board meetings.
Duncan Burton, Chief Nursing Officer for England, emphasised the significance of this development:
“There have been too many times where safety issues in maternity could have been detected earlier, and we have seen the devastating impact this has had on families.”
“Having a signalling system for maternity which can carefully look at data in near real-time and spot early warning signs if something is potentially going wrong will help to avert safety incidents and prevent tragedies.
It is the first national system of its kind in maternity to be able to signal potential safety issues as they emerge and allow them to be acted on faster by maternity services.
And it will be the responsibility of staff in maternity services and hospital’s board executives to urgently act on warning signals so problems can’t be ignored or delayed.”
Cambridge University Hospitals NHS Foundation Trust was among the first to pilot MOSS. Cathy Bevens, lead safety and governance midwife, shared her experience:
“We have had really positive experiences using the signal system – colleagues feel like we are being responsive. The system and safety check brings us together as a team and makes us really focus on what the issues are and where care can improve.
It’s encouraged senior leaders and executives to come and talk to staff and services users, to listen their issues and concerns. This has prompted a building of trust and teamwork, and acknowledgement of the lived experiences of women on the labour ward. Overall, a really positive experience.”
Health leaders believe the visibility of early signals at all levels will foster a culture of openness and continuous improvement in maternity care.
The Origins of MOSS
MOSS was developed in direct response to recommendations from the “Reading the Signals” report, following Dr Bill Kirkup’s independent investigation into East Kent maternity and neonatal services. The report called for a system capable of distinguishing meaningful safety signals from background noise and displaying significant trends for mandatory national use.
The development team included Dr Bill Kirkup, Professor David Spiegelhalter—an authority on statistical risk—alongside families and service users. Dr Kirkup commented:
“This is a really positive development that originated directly from the investigation into East Kent maternity services. The families there who did so much to bring this to light deserve great credit for the improvements it will bring.”
Chris Binnie, a national service user representative whose son Henry was stillborn at 38 weeks due to undetected intrauterine growth restriction, added:
“The culture of curiosity that MOSS enables gives maternity services the opportunity to learn well and to drive through change.
This is hugely important to service users and can help prevent the tragedy of avoidable stillbirths and neonatal deaths happening to families in future.”
A Proven Approach
Safety signal systems are already used in other areas of healthcare, such as children’s cardiac services and paediatric intensive care, employing cumulative sum control chart methodology to detect trends in rare but serious events. MOSS applies this proven statistical approach specifically to intrapartum care safety.
Government Commitment
Health and Social Care Secretary Wes Streeting reinforced the government’s commitment to improving maternity care:
“For the past 18 months, I have met with bereaved and harmed families across the country who have lost babies or suffered serious harm during what should have been the most joyful time in their lives.
What these families have experienced is deeply upsetting – painful stories of loss, trauma, and a lack of basic compassion. For too long, maternity warning signs have been missed.
Now, this is a key step we are taking to improve maternity care. We have a sophisticated early warning system that will sound the alarm when patterns emerge that need urgent attention. Every signal will be visible from ward to boardroom, and every signal will be investigated.
Alongside this, the rapid national investigation will also help us deliver long-lasting change to maternity and neonatal care across the country, and I am setting up a maternity and neonatal taskforce to ensure this change is delivered.
We are making sure failures of the past cannot be repeated, and that every mother and baby receives the safe care they deserve. I will do everything in my power to ensure no family has to suffer like this again.”
Clea Harmer, Chief Executive, added:
“Early detection of serious safety issues is vital in saving babies’ lives so it’s very important that all maternity services have access to this data and that boards have oversight and act swiftly on any concerns flagged by the Maternity Outcomes Signal System (MOSS).
This rollout is a welcome step to improve safety monitoring across NHS maternity services and it’s encouraging to see recommendations from Reading the Signals being implemented, reinforcing the importance of learning from data to drive continuous improvement in maternity safety.”
Looking Ahead
The rollout of MOSS is part of NHS England’s broader strategy to improve maternity and neonatal care, which also includes initiatives like the Perinatal Equity and Anti-Discrimination Programme. Together, these measures aim to ensure every mother and baby receives the safe, compassionate care they deserve.
Image credit: iStock
