One hit a pregnant teacher, another exposed himself and another stabbed a classmate with a pencil.

They've all been suspended from school this year. And they're all kindergartners.

In the first four months under new schools chief Paul Vallas, 33 kindergartners have been suspended from Philadelphia public schools, up from just one during the same period last year.

"The goal is to get the parents in," said Gwen Morris, who oversees alternative education for the 200,000-student district. "What it says is: We have a uniform policy that everyone will be held to."

The U.S. Department of Education does not break down school suspensions by grade level, but several researchers said they see anecdotal evidence that the youngest schoolchildren are being suspended more frequently.

Morris believes suspensions, combined with counseling and other measures, are an effective tool in the city's crackdown on school violence. None of the kindergartners has been suspended a second time, she said.

Walter Gilliam, a child psychologist at Yale University's Child Study Center, said he doubts young children make the connection between an action in school and the ensuing suspension, which can last 10 days.

"Ten days is a lifetime to a 3-, 4- or 5-year-old," said Gilliam, who is working on a study of preschooler suspensions. "They can't even fathom 10 days. It's like waiting for Christmas.

"I think it's a bad move, because it absolves the school from feeling that it's necessary to deal with that problem within the school building. You push it out to the community, you push it out to the family home, and that's where it started to begin with," Gilliam said.

Gilliam is studying suspensions in Connecticut, where 311 kindergartners were suspended in 1999-2000, about 92 percent of them out-of-school suspensions.

Gilliam said 79 percent of Connecticut's kindergarten suspensions went to boys, and about half involved allegations of physical violence, sexual harassment or verbal threats.

Nearly 52 percent of the suspensions went to black kindergartners, 35.2 percent to Hispanics and 12.1 percent to whites, he said.

"Those percentages do not match the demographics of Connecticut," Gilliam said, echoing criticism from the Rev. Jesse Jackson and others that "zero tolerance" policies and other disciplinary codes are disproportionately applied to minorities.

Among Connecticut kindergartners, 75 percent of the suspensions went to students from the lowest socioeconomic rung, Gilliam said.

That suggests to Peg Oliveira of Connecticut Voices for Children that low-income students are not getting high-quality preschool.

The pre-kindergarten experience probably isn't preparing them for what they need to do before they get to kindergarten," said Oliveira, whose child-advocacy group has researched the issue.