The 8-month-old baby was stabbed several times, but was listed in good condition at Johns Hopkins Children's Center and was expected to survive, Police Det. Donny Moses said.
"The baby should be OK," Moses said.
The mother was admitted to an area hospital for a mental health evaluation, police said.
Police spokesman Anthony Guglielmi said the stabbing occurred shortly before 10 a.m. at a Department of Social Services building where entering visitors must pass through metal detectors and have their bags screened.
The woman, the baby and a social worker were in a room together when the stabbing occurred, Moses said. He added that the woman became irate before the stabbing, but he didn't know why. The police spokesman did not provide other details.
Authorities did not immediately identify the woman. Moses said a decision on charges would be made after she is released from the hospital, but he did not know how long the evaluation would take.
Pat Hines, a spokesman for the state Department of Human Resources, said the office where the stabbing occurred is mainly focused on foster care services. Hines said the woman entered the building through normal procedures and the department has begun a review of security procedures at all of its buildings statewide.
