Problems monitoring the heart rate of babies during labour are contributing to brain damage and stillbirths, according to a new report.
The study, from the Royal College of Obstetricians and Gynaecologists (RCOG), calls for a raft of actions to immediately reduce the numbers of babies dying or suffering brain injury due to problems or mistakes in labour.
Experts said there were an average of six factors that contributed to poor outcomes for each of the 1,136 babies born in 2015 that were studied for the RCOG's Each Baby Counts initiative.
Of these babies,126 were stillborn, 156 died within the first seven days after birth and 854 babies suffered severe brain injury.
Some 76% of 727 babies where full information was available may have had a "different outcome with different care", the RCOG said.
The Each Baby Counts initiative aims to halve the number of babies who die or are left severely disabled as a result of preventable incidents occurring during full-term labour by 2020.
Among the problems identified are mistakes with foetal heart rate monitoring.
The RCOG is calling for NHS trusts to ensure all staff have documented evidence of appropriate annual training in this area.
It also wants all low-risk women to be assessed on admission to the labour ward for whether they need intermittent or continuous monitoring.
Mistakes in foetal heart rate monitoring are at the centre of a probe into seven baby deaths between 2014 and 2016 at Shrewsbury and Telford Hospital NHS Trust.
Dr Ed Prosser-Snelling, the quality improvement lead for Each Baby Counts, said interpreting heart rate traces can be difficult.
He said: "The main problem is that if you show two people the same the monitoring trace, they are likely to give you two separate answers."
However, he said there were were "countless reports" detailing failings in interpreting heart rate traces.
"We know that people do get it wrong," he said. "Whether it's because they are not properly trained or whether it's because it's difficult is hard to pin down.
"I think it's probably a bit of both."
Dr Prosser-Snelling said there was a need for staff to "make a holistic assessment" during labour, looking at all factors such as the mother's heart rate, whether she has a temperature and facts that are already known, such as the woman's body mass index.
An analysis of local reviews for the babies in the study found that a quarter did not contain sufficient information to draw conclusions about the quality of care provided.
Of 727 thoroughly conducted local reviews, parents were only invited to be involved in 34% of them, with 19% of parents not even told an investigation was going on.
Major recommendations in the report include senior staff such as the senior registrar, consultant or senior midwife, having a "helicopter view" of what is going on at the time of delivery.
The report also calls for improved "situational awareness", such as seeking different points of view if staff feel stressed or tired.
External panel members - such as from another trust or a non-executive director - should also sit on local reviews.
At present, this figure is 9%, which could lead to the "perception that people could be marking their own homework," Dr Prosser-Snelling said.
Co-principal investigator Professor Zarko Alfirevic said: "Problems with accurate assessment of foetal well-being during labour and consistent issues with staff understanding and processing of complex situations, including interpreting foetal heart rate patterns, have been cited as factors in many of the cases we have investigated."
Janet Scott, research and prevention lead at the charity Sands, said: "I am deeply shocked by this unacceptable rate of harm to babies in labour. The failure to carry out thorough reviews of what happened is inexcusable and must change."
Mandy Forester, head of quality and standards at the Royal College of Midwives, called for "immediate improvements" in the investigation of such baby deaths but also said many more midwives were needed across England.
"It is only through thorough investigation and implementation of recommendations that lessons can be learned from these tragic events," she said.
"We must do everything possible to prevent them, and improve care and safety.
"Too often the focus is on individual actions. All healthcare professionals must of course be rigorous in their practice. However, they are often working in systems that do not support best practice, and the safest and highest quality care as well as they should."