Hundreds of stillborn babies can be saved if their mothers are given better care in pregnancy, according to a major report.
More than 1,000 babies without any congenital abnormality die at or near term, before labour begins, in Britain every year.
Experts reviewed in detail a representative sample of 85 of these stillbirths and found there were failures in the care of half of them.
The team found that warning signs were missed. Half the pregnant women whose babies died had told medical staff they were worried that the baby in the womb was no longer moving.
In half of those cases, there was either no investigation, the baby's heart rate was monitored but misinterpreted, or staff in the maternity unit failed to respond correctly to warning signs.
Tests that would have alerted staff to the need to monitor the pregnancy more closely were not carried out. Women at risk of developing diabetes were not tested. National guidance for checking that the baby in the womb was growing normally was not followed.
Opportunities to learn from the deaths were not taken - in only a quarter of cases was there an internal review of what had happened and the quality of the reviews was highly variable, said the experts.
Sands, the charity supporting parents whose babies are stillborn or die soon after birth, which took part in the investigation, said there appeared to have been little progress over the last 15 years.
"One in three babies who are stillborn die at term, a time when they are likely to have survived outside the womb had they been safely delivered earlier," said Ms Judith Abela, the acting chief executive.
"But this report tells us hundreds of deaths could be avoided today simply by applying existing antenatal guidelines. It's particularly worrying that so many women's concerns about changes in their baby's movements are not being taken seriously and that a baby's poor growth is not being spotted by simple checks," she said.
The investigations were carried out by a team of academics, clinicians and charity representatives called MBRRACE-UK (Mothers and Babies: Reducing Risk Through Audits and Confidential Enquiries Across the UK).
The panel had identified several areas where care could be improved, said lead author Elizabeth Draper, a professor in perinatal and paediatric epidemiology at University of Leicester. But not all the findings were negative.
"We found examples of excellent bereavement care where midwives had provided long-term support for families in a way that surpassed normal expectations, high-quality interpreter services when these were needed, as well as a high standard of post-mortems," she said.
Royal College of Paediatrics and Child Health president Neena Modi said: "The report indicates that opportunities to prevent this may be being missed."
But she also called for more to be done to help pregnant women reduce risky behaviours such as smoking. "Smoking during pregnancy is a major concern as it causes higher rates of stillbirth, premature birth, low birth weight and sudden infant death in babies," said Professor Modi.