Elizabeth Maddocks died after caesarean section at Maelor hospital
Lessons must be learned following the death of a mother less than 24 hours after giving birth to a daughter by caesarean section, an inquest was told.
Elizabeth Maddocks, 42, from Wrexham, was not given blood-thinning medication for more than 12 hours after surgery.
She died due to deep vein thrombosis at Wrexham Maelor Hospital despite complaining of a swollen leg, the hearing at Ruthin was told.
Hospital's bosses said they were "very sorry".
After the inquest, Mother-of-three Ms Maddocks's family released a statement via their solicitor.
In it, her fiancee Wayne Jones said: "Amy and Oliver have lost their mum. Lily will never know her mother.
"Had Liz received the proper care, her death could have been avoided."
The inquest was told that Betsi Cadwaladr University Health Board had produced a report making a number of recommendations following the case.
But assistant coroner David Lewis said he was not able to conclude that all the recommendations had been implemented since the death in February last year.
Reaching a narrative conclusion, Mr Lewis said he would be writing to health officials to highlight his concerns and asking for a response on what lessons had been learned.
A health board spokesperson said: "We are very sorry that the level of care we provided to Miss Maddocks was not sufficient to prevent this tragic outcome.
"We are waiting to receive the coroner's comments, and will ensure that any issues that are raised are addressed in full."