Stark, shared maternity rooms will go the way of outdated wards at North Shore University Hospital in Manhasset and Long Island Jewish Medical Center in New Hyde Park, where 161 new suites will each include a bassinet for the newborn and a private bathroom. The opening in September of 36 private rooms with hotel-like amenities at Stony Brook University Medical Center, the construction now under way of 88 single suites at Long Island Jewish and plans to build 73 such rooms at North Shore next year are part of a move toward single-occupancy maternity accommodations.