Babies and mothers are at risk of injury and death because too many maternity units have not improved care despite a string of childbirth scandals, the NHS watchdog has warned.

In a highly critical report published on Tuesday, the Care Quality Commission (CQC) voiced serious concern that lessons are not being learned and that many incidents involving patients’ safety are still not being recorded.

Some hospitals have been “too slow” to take the steps needed to make labour and birth safer, despite multiple inquiries, reports and recommendations to do so, it said.

The CQC also found other persistent weaknesses in maternity care, including tension and difficulties between obstetric doctors and midwives and poor oversight of risks to patients during an in-depth inspection of maternity care at nine hospitals in England. The NHS has been criticised for major maternity scandals involving poor care, which sometimes persisted for many years, at trusts such as Morecambe Bay, East Kent and Shrewsbury and Telford.

The government, NHS leaders and patients have pressed the NHS in England to overhaul maternity safety to reduce the number of babies being left brain-damaged or dead and mothers injured or dead as a result of poor care during childbirth.

The watchdog also criticised hospitals for doing too little to seek the views from black, minority ethnic and poorer communities about how to improve their experience of giving birth. Black women are four times more likely to die in childbirth than white women, and Asian women twice as likely.

“We know that many maternity services are providing good care, but we remain concerned that there has not been enough learning from good and outstanding services,” said Ted Baker, the regulator’s chief inspector of hospitals.

He stressed that the CQC’s findings were not representative of the quality and safety of maternity care across England as a whole because the nine hospitals it visited were chosen because evidence suggested patients were being put at risk.

However, he added: “But we cannot ignore the fact that the quality of staff training; poor working relationships between obstetric and midwifery teams, and hospital and community-based midwifery teams; a lack of robust risk assessment; and a failure to engage with and listen to the needs of local women all continue to affect the safety of some hospital maternity services today.”

Baker also castigated staff in some units for a lack of transparency when things go wrong, which denies families explanations and makes the changes that are necessary less likely to occur. “The death or injury of a new baby or mother is devastating and something that everyone working in the health and care system has a responsibility to do all they can to prevent.

“It is essential that we have a system that is open, and that recognises, investigates and learns when things go wrong, so that families get the truth and safety continually improves”, he said.

In the report, a woman named only as Tinuke explains how she was diagnosed with pre-eclampsia – dangerously high blood pressure – very late in her pregnancy.

After being admitted to hospital as an emergency case, “my labour progressed really quickly, but the midwife refused to believe that I was actually in labour. I was left alone for hours without any pain relief.

“By the time I was told I could push, I was so exhausted that I had to have an assisted delivery. It’s not how I wanted to bring my son into the world. The whole experience was extremely traumatic and could have been avoided if I had been listened to,” she added.

The report says that despite a renewed focus in recent years on maternity care, “the pace of progress has been too slow and action to ensure all women have access to safe, effective and personalised maternity care has not been sufficiently prioritised to mitigate risk and help prevent future tragedies from occurring”.

In 2018 the CQC disclosed that it had rated 50% of maternity units as either “requires improvement” or “inadequate”. Although that proportion had fallen to 39% by March 2020, it has risen again since to 41%, the new report says.

The Royal College of Midwives said it backed the drive for safer care. But Dr Mary Ross-Davie, its director for professional midwifery, highlighted the serious NHS-wide shortage of midwives.

“We also need to be realistic and ensure there are enough midwives to implement this [personalised care] safely. Right now, right across the UK, most services are understaffed, with some shifts barely at 50% capacity. That is why the RCM has called on the government to ensure we have enough midwives, so women are getting the maternity care they need and deserve,” she said.

An NHS spokesperson said: “The NHS is committed to providing safe, compassionate maternity services, and has invested an additional £95m into workforce numbers and training programmes to improve leadership.

“We continue to tackle poorer outcomes including by introducing our new equality strategy and fast-tracking our continuity of carer programme, which is proven to significantly improve their overall experience of care.”