An unnamed family doctor breached patient rights by prescribing an oral contraceptive pill to a high-risk patient without carefully reviewing the risks, according to a report.
The medical centre where the doctor worked and not identified is also faulted in the report from the Health and Disability Commissioner.
Anthony Hill says the woman in her late 30's was prescribed the combined oral contraceptive pill Estelle over three-and-a-half years without adequate review or discussion of her risk factors.
The woman had an ovary condition for which Estelle is used, but was also obese and a smoker with a family history of blood clots - all risk factors for those taking the drug.
Mr Hill says the woman's GP prescribed the pill without properly assessing her suitability or recording her blood pressure.
The woman later had gall bladder surgery, developed a blocked artery and died.
Mr Hill says the risks needed to be discussed and monitored, and proper records kept.
"There were a series of unsatisfactory and sub-optimal aspects to the care over time. And one of those was because the system itself was not reminding people, assumptions were being made that the things that ought to have been done had been done previously, without the system being checked or, in fact, asserting they had been."