professional confidence

A woman confided to her psychologist in a treatment session that she has not been attending the mikvah for the last several months and doesn't plan to in the future, without the knowledge of her husband.

Question: Is the psychologist obligated to betray professional confidence and inform her husband that his wife is causing him to transgress a biblical prohibition?

("Thou shall not stand idly by…")

On the other hand, , betraying professional confidence will possibly 1) cause the client to discontinue vital psychological treatment; 2) discourage other people that are in need of psychological treatment from going to religious therapists; 3)significantly reduce potential referrals, and thereby, the therapist's income.

In addition to the above concerns,his reputation and position may be endangered; he may be liable to suits; he will be transgressing the state/country's laws ("Dina De'malchuta") and liable to punishment from a half to three years imprisonment.

I will greatly appreciate a response at your earliest convenience.