An Allegheny County judge today postponed a hearing for a woman accused of poisoning her baby with a salt overdose but not for a woman accused of cutting an unborn baby from another woman's uterus, killing that woman in the process.

Dr. Christine Martone, chief of psychiatry at the county jail, testified at competence hearings for both women today that both were mentally unfit to participate in their defenses.

Judge Jeffrey Manning ordered Amber Brewington to undergo 90 days of evaluation at Mayview State Hospital, thereby postponing her preliminary hearing. Ms. Brewington is accused of injecting her infant, Noah King, with saline solution, including while he was hospitalized at UPMC Children's.

Dr. Martone said Ms. Brewington is on a suicide watch and not capable of aiding her own defense.

Ms. Brewington, 21, of Tennessee, was arrested July 15 when she admitted to police that she injected salt water into her son's feeding tube, according to a criminal complaint.

She blamed "severe" post-partum depression for her decision to inject her infant son at Children's and, before that, a hospital in Nashville, Tenn., according to Pittsburgh police.

Judge Manning did order that a preliminary hearing for Andrea Curry-Demus will go forward tomorrow despite Dr. Martone's testimony.

Ms. Curry-Demus is accused of cutting a baby from the womb of Kia Johnson last week, taking the baby and killing Ms. Johnson.

The baby was not seriously hurt and has been released from a hospital.

During today's hearing, Judge Manning asked Ms. Curry-Demus some brief questions and determined she understood the charges against her.

Dr. Martone described her as "psychotically ill" and "very paranoid" and, although Ms. Curry-Demus denied having hallucinations, Dr. Martone believed that she was having them while being interviewed.

Ms. Curry-Demus, 38, of Wilkinsburg, is charged with homicide, kidnapping, unlawful restraint and endangering the welfare of a child.