HOUSTON -- Andrea Yates has again pleaded not guilty by reason of insanity in the drowning deaths of her children.

The plea came Monday in the Houston woman's first court appearance since her 2002 capital murder convictions were overturned.

Yates was clear-eyed, alert and heavier than she appeared in her last court appearance in November. State District Judge Belinda Hill read the charge and Yates' attorney George Parnham entered a plea of not guilty by reason of insanity for her.

A judge set the Yates case for a March 20 trial in Houston. Yates will remain in the custody until then.

During her time in prison, Yates' condition has improved as she has undergone constant mental health treatment. However, her attorneys said they are concerned that going through another trial might cause her to break down.

"My concern, of course, is that there is always a danger that she could decompensate given the surroundings of incarceration at the Harris County Jail," Parnham said.

Yates' mother was in court but did not answer questions from the media concerning Monday's events.

A plea bargain is expected to be worked out between prosecutors and Yates' attorneys to avoid a second trial.

"I don't know the parameters of any agreement that might work out because we don't have an agreement. There will be interim sessions and we will continue to talk with defense attorneys, as well as prepare for trial," prosecutor Joe Owmby said.

Jurors rejected Yates' insanity defense during her original trial and found her guilty in the 2001 deaths of three of the five children drowned in the family bathtub. She was sentenced to life in prison.

Evidence was presented about the drowning of the other two children, but Yates was not charged in their deaths.

A state appeals court in Houston overturned Yates' convictions last January because of false testimony from a prosecution expert.