A state report says early academic gains by children in Iowa's preschool program have been lost by third grade.
The report says the preschool students made modest gains on a school readiness assessment, but the program impact vanishes later in reading and mathematics.
Iowa Education Department Director Jason Glass says the study echoes a 2012 report that shows children in the federal Head Start program don't retain long-lasting increases in achievement.
Glass says the report issued Wednesday shows the state should develop better instruction for its Statewide Voluntary Preschool Program.
He says "quality preschool programs do show long-term impacts. Our preschool is not showing an impact, at least after four years."
The study compared the academic performance of students who attended the preschool program to students who didn't attend.