This week, the Government's healthcare inspectorate is expected to say that an acute shortage of midwives, equipment shortages and dirty wards has contributed to the deaths of mothers or babies.
These findings from Sir Ian Kennedy, the head of the Healthcare Commission, are the result of an investigation into three maternity units.
At Northwick Park in North London 10 women died during or after birth in three years, which is five times the national average. Among those who died was 27-year-old Premalatha Jeevagan. The new mother had been healthy but died at the hospital in February when doctors failed to realise that she had suffered a womb haemorrhage.
A review by commission inspectors at New Cross hospital in Wolverhampton found that half of the 20 babies that died there might have survived with better care.
At Ashford and St Peter's NHS trust in Surrey, no evidence of unnecessary baby deaths was found but the inspectors concluded that poor working relations between consultants was jeopardising patient care.
The Government is expected to respond by publishing its own action plan for improving maternity care on Wednesday. This will include the establishment of an expert advisory group to devise a new system of standards for maternity units.