Hoag Memorial Hospital Presbyterian, Newport Beach, Calif., told its Orange County doctors this week that they'll no longer be allowed to perform elective abortions after finalizing its partnership with a Catholic hospital group.

Hoag's CEO Robert Braithwaite told the Orange County Register the new rule wasn't imposed by St. Joseph Health System, and was based on medical reasons, not religion.

Contraception and abortions are prohibited at St. Joseph's.

Some of Hoag's gynecologists and obstetricians say they're surprised and upset by the change, adding they were led to believe the new affiliation wouldn't change the nature of care they could offer. They're skeptical the change doesn't reflect St. Joseph's Catholic values.

Braithwaite says the hospital performs fewer than 100 such abortions a year, and low volume can mean low quality of care.