Concerns have been raised about the healthcare provided to a South Yorkshire mum who died weeks before she was due to give birth to her third child.
Lyndsey Holt was 37 weeks pregnant when she died on April 3, 2016, of shock and haemorrhage caused by a perforated gastric ulcer.
An inquest into her death heard she had been prescribed methadone over the phone, which she used to reduce the pain of her varicose veins.
The 36-year-old also took paracetamol and other painkillers in the run-up to her death.
The inquest also heard how ambulance controllers failed to pass on important information to Rotherham Hospital, which may have helped them prepare better for her arrival, after she collapsed at home.
Nicola Mundy, senior coroner for South Yorkshire, has written to both Dinnington Group Practice, in Rotherham, and to Yorkshire Ambulance Service to raise concerns which she believes could lead to future deaths if they are not addressed.
In her report to the practice at The Medical Centre, in New Street, Dinnington, she said she was concerned about the methadone being prescribed over the phone, with no face-to-face consultation.
She also expressed concern about what she said was a lack of detail about how the drugs were being taken by Ms Holt, the degree - if any - of her dependence, and the decision to provide a 'methadone naive patient' with a seven-day supply of the drug.
Writing to the ambulance service, she raised concerns about the training of control room staff and the lack of systems in place to audit the effectiveness of the pre-alert system to help hospitals prepare to receive critically ill patients.
In the reports, dated March 29 but only just published, she asked both the practice and the ambulance service to provide details of any action they have taken or propose to take to address her concerns.