Leading patient advocate Mark Molloy has resigned from the Health Service Executive Board.
Mr Molloy was appointed by Minister for Health Simon Harris in January last year, along with several other members.
Mark and Roisín Molloy's son, Mark, died shortly after birth at the Midland Regional Hospital, Portlaoise, in 2012 and their case contributed to the major review into baby deaths at the hospital.
In 2014, the Offaly couple settled a legal action against the death of their son.
In a statement, the couple said it was "a very difficult decision to resign from the board".
They added: "However by not having a veto on significant board decisions that we had issue with given our in-depth knowledge of the intricacies of the workings of the HSE, of the processes by which they were made, we were by extension being complicit in these decisions.
"Our aim has always been to act at all times in the interests of patients above all and we believe that the integrity that we have built up over the past eight years would be eroded by our continued involvement on the board."
Mr Molloy is a quantity surveyor and a member of the Expert Group on Tort Reform and Management of Clinical Negligence Claims.
The appointment of patient advocates to the HSE Board was a recommendation by Dr Gabriel Scally in his report into the CervicalCheck controversy to ensure the board would have members with patient advocacy experience and expertise.
At the time of Mr Molloy's appointment, one of the stated priorities of the board was to develop a plan for building public trust and confidence in the HSE and the wider health service.
The resignation of Mr Molloy follows a number of concerns raised by patient advocates and campaigners in separate cases in recent months.
CervicalCheck campaigner Lorraine Walsh resigned from the CervicalCheck Steering Group late last year, after she said she had lost confidence in the UK review of slides by the Royal College of Gynaecologists.
Separately, the woman whose case last year led to details becoming public of an IT glitch, which caused test result delays in the CervicalCheck programme, has said she remains dissatisfied with the attitude of the Department of Health to her experience.
Sharon Butler Hughes' case was outlined in the Rapid Review report published last August by Professor Brian MacCraith and commissioned by HSE Chief Executive Paul Reid.
Ms Butler Hughes first raised concerns over significant delays in her test results in a series of emails to the Department of Health last April.
The MacCraith Report detailed how her account of a telephone conversation with a Department of Health official in July was disputed by the official.
Ms Butler Hughes recently wrote to the HSE to express her dissatisfaction about the matter.
A meeting between Ms Butler Hughes and Minister for Health Simon Harris, which was due to take place last November, was cancelled at short notice.
At the time, the department told Ms Butler Hughes that it had come to the minister's attention that a letter of claim had recently been issued on her behalf and the minister had been advised that it would be inappropriate to meet her and her legal representative.