The Connecticut Supreme Court will be deciding an issue that most people may think is already settled — whether medical providers have a duty to keep patients' medical records confidential.

A trial court judge in Bridgeport, Richard Arnold, ruled in 2015 that Connecticut law, unlike laws in many other states, has yet to recognize a duty of confidentiality between doctors and their patients, or that communications between patients and health care providers are privileged under common law.

The decision came in a paternity case where a doctors' office in Westport sent the medical file of a child's mother without her permission to a probate court under a subpoena issued by the father's lawyer — not a court — and the father was able to look at the file.

The mother, Emily Byrne, a former New Canaan resident now living in Montpelier, Vermont, sued the Avery Center for Obstetrics & Gynecology in 2007 for negligence in failing to protect her medical file and infliction of emotional distress. She alleges the child's father used her highly personal information to harass, threaten and humiliate her, including filing seven lawsuits and threatening to file criminal complaints.

But Arnold dismissed the claims, saying "no courts in Connecticut, to date, recognized or adopted a common law privilege for communications between a patient and physicians."

The state Supreme Court is scheduled to hear arguments in the case Monday. Byrne, a nurse, referred questions to her lawyer, Bruce Elstein, who said the case will result in an important, precedent-setting decision by the Supreme Court.

"The confidentiality of medical information is at stake," Elstein said. "If the court rules in the Avery Center's favor, the tomorrow for medical offices will be that no patient communications are privileged. Their private health information can be revealed without their knowledge or consent."

A lawyer for the Avery Center didn't return messages seeking comment. The concept of doctor-patient confidentiality dates back roughly 2,500 years to the ancient Greek physician Hippocrates and the famous oath named after him that includes a pledge to respect patients' privacy.