One of the region’s major providers of health care to children, Penobscot Pediatrics of Bangor, has ended a decades-old arrangement in which its doctors delivered checkups and routine care to newborn patients at Northern Light Eastern Maine Medical Center. When the group stopped sending pediatricians to the Bangor hospital’s newborn nursery at the beginning of February, it freed them up to provide more of the outpatient services that they regularly deliver at their office on Union Street and for which there has been an increasing need, according to Dr.