Almost 20% of NHS trusts have been branded "red" for infant mortality rates.
The 23 trusts were labelled red in 2020 because their infant death rate was more than five per cent above average.
The shocking statistic was highlighted in a report from by the Mothers and Babies: Reducing Risk through Audit and Confidential Enquiries (MBRRACE).
Another report from the group discovered that the number of women who died within six weeks of having their child was up by a quarter over five years.
Some 229 mums died along with 27 of their children from 2018 to 2020 - and many of the deaths were "avoidable", the Daily Mail reports.
The MBRRACE's audit found that six NHS trusts were rated red for both stillbirth and neonatal births.
The other 17 trusts marked red after the two separate measures were combined for an overall rating.
The trusts branded red for both stillbirth and neonatal births were: University Hospitals Coventry & Warwickshire, University Hospitals of Leicester, Buckinghamshire Healthcare, Gloucestershire Hospitals, Sandwell and West Birmingham Hospitals and University Hospitals Dorset.
UK mums are over three times more likely to die during pregnancy compared with mothers in Norway and Denmark, according to a study published in the BMJ.
The rates of death among mothers in pregnancy and up to 42 days after the birth of their child varied from 2.7 per 100,000 live births in Norway to 10.9 per 100,000 in Slovakia.
There were 9.6 maternal deaths for every 100,000 babies born in the UK, meaning Britain had the second highest rate of the eight European countries involved in the study.
Across all eight nations, maternal deaths were higher in the youngest and oldest mothers.
In seven countries mothers born abroad or with an ethnic minority background had a 50% or greater risk of maternal mortality.
The finding did not hold true in Norway. Researchers said heart disease and suicide were the leading causes of death.
In the UK blood clots were also a leading cause of death among new mothers.
"Despite its rarity in high-income countries, maternal mortality remains an important health indicator of the quality of the care provided and health system performance," the authors wrote in their new study, published in The BMJ.
"Maternal mortality ratios up to 42 days after the end of pregnancy varied by a factor of four, from 2.7 and 3.4 per 100,000 live births in Denmark and Norway to 9.6 in the UK and 10.9 in Slovakia."
NHS England has been approached for comment.
