One in eight health bodies have higher-than-expected rates of stillbirths and neonatal death, a new report suggests.
Hospitals with higher-than-expected perinatal mortality - stillbirths and deaths after up to 28 days of life - have been highlighted in the new MBRRACE-UK (Mothers and Babies: Reducing Risk through Audits and Confidential Enquires across the UK) report.
Experts grouped broadly similar organisations together by their type and size to compare mortality rates.
After examining UK perinatal deaths for births from January to December 2015, they came up with a traffic light system to highlight those where action needs to be taken to improve outcomes.
Of 165 NHS trusts and health boards across Britain, 21 of 165 (12.7%) have been labelled as "red" - meaning that they have a mortality rate which is over 10% greater than the average for that type of organisation.
The authors of the report have called on these organisations to investigate the possible causes behind the higher rates.
Researchers said 54 organisations fell into the amber category - meaning they had a mortality rate up to 10% higher than their group's average; 78 were in the yellow category - meaning their mortality rate was up to 10% lower than the average for similar organisations and 12 were green - indicating that their mortality rates were more than 10% lower than average for their group.
Dr Brad Manktelow, associate professor at the University of Leicester, who led the statistical analysis, said: "Those trusts and health boards identified with high rates of stillbirth or neonatal death rates should review the quality of the care they provide.
"Work commissioned by the Healthcare Quality Improvement Programme is under way to develop a standardised perinatal mortality review tool to support and improve the quality of review of all stillbirths and neonatal deaths within all trusts and health boards in the future".
Overall, researchers found that the rate of stillbirth in the UK reduced by 8% between 2013 to 2015.
In 2015, the stillbirth rate was 3.87 per 1,000 total births, a fall from 4.20 per 1,000 total births in 2013.
But the authors said that despite the fall, UK stillbirth rates still remain high compared with many similar European countries and there remains "significant variation" across Britain.
The neonatal death rate remained fairly static with a fall between 2013 and 2015 from 1.84 to 1.74 deaths per 1,000 live births.
Commenting on the report, Mandy Forrester, head of quality and standards at the Royal College of Midwives (RCM), said: "This is a welcome reduction and things are moving in the right direction but there is still much more to do if we are going to match the lower stillbirth rates of other European countries.
"There is rightly a need to tackle neonatal death rates which have not fallen as much as the stillbirth rate. However, there is clearly a need to put even greater efforts into reducing both.
"The variation in stillbirth rates across the UK remains a concern. This could be because of the socio-economic wellbeing of communities, and we know inequality is linked to higher stillbirth rates and poorer outcomes for the baby. It may also be in the quality of local services and this needs investigation.
"It is imperative that we learn from each of these tragic deaths. Health services must strive to learn from each other about the best ways to prevent this. Sharing success stories and strategies is key to this."
Professor Lesley Regan, president of the Royal College of Obstetricians and Gynaecologists, added: "Although the findings are welcome, there is still some way to go to address the high death rates and level of variation across the UK, which are still too high when compared to similar European countries.
"Disappointingly, the findings only show a small reduction in neonatal death rates.
"This week, we published the key clinical actions needed to improve quality of care and to prevent deaths and brain injuries that occur during childbirth, as part of our Each Baby Counts initiative.
"These key actions include adhering to best practice on foetal monitoring and neonatal care, as well as addressing potential human factors that lead to poor decision making in stressful situations.
"The RCOG also publishes maternity indicators, which describe patterns of care during labour and delivery, enabling trusts to examine their own practice in context and to ensure their services meet the needs of women and their families.
The college also works closely with hospitals which invite us to conduct external reviews of their maternity services to identify where improvements can be made."
The 21 organisations labelled as being "red" for their perinatal mortality rates are:
:: Belfast Health & Social Care Trust
:: Birmingham Women's NHS Foundation Trust
:: Cambridge University Hospitals NHS Foundation Trust
:: Guy's and St Thomas' NHS Foundation Trust
:: Liverpool Women's NHS Foundation Trust
:: Sheffield Teaching Hospitals NHS Foundation Trust
:: University Hospitals Bristol NHS Foundation Trust
:: East Lancashire Hospitals NHS Trust
:: Homerton University Hospital NHS Foundation Trust
:: The Royal Wolverhampton NHS Trust
:: Royal Berkshire NHS Foundation Trust
:: Sandwell & West Birmingham Hospitals NHS Trust
:: Southern Health & Social Care Trust
:: The Dudley Group NHS Foundation Trust
:: The Shrewsbury and Telford Hospital NHS Trust
:: Worcestershire Acute Hospitals NHS Trust
:: Countess of Chester Hospital NHS Foundation Trust
:: Kettering General Hospital NHS Foundation Trust
:: Royal United Hospitals Bath NHS Foundation Trust
:: Salisbury NHS Foundation Trust
:: Dorset County Hospital NHS Foundation Trust
A spokeswoman for NHS England said: "Last year, we focused the NHS's efforts around four key areas specifically aimed at tackling stillbirth which will build on the improvements which have seen more than 600 children alive today compared to ten years ago.
"We are on track to meet the national ambition and the vast majority of maternity services are reporting they are taking forward improvements, meaning fewer families are likely to suffer the terrible tragedy of stillbirth and neonatal death."
Health Secretary Jeremy Hunt said: "I want to make the NHS one of the safest places in the world to give birth by halving rates of stillbirth and neonatal deaths by 2030, and this report shows we are making significant progress towards achieving this.
"However, there is still more to do to ensure fewer families suffer the heartache of losing a baby - that's why we have invested millions in training for staff and new safety equipment, as well as making sure hospitals review and learn from every tragic case."