—Judgment, Supreme Court, Bronx County (Gerald Sheindlin, J.), rendered August 30, 1991, convicting defendant, after a jury trial, of rape in the first degree (2 counts), sodomy in the first degree, sexual abuse in the first degree (2 counts) and endangering the welfare of a child and sentencing him to terms of from 8V3 to 25 years on each rape conviction, 8 Vs to 25 years on the sodomy conviction, 2Vs to 7 on each sexual abuse conviction and a determinate term of 1 year on the endangering the welfare of a child conviction, all sentences to run concurrently, unanimously affirmed.
Expert testimony concerning child sexual abuse syndrome *364was relevant and helpful to the jury’s understanding of child abuse victims, a subject not within the ken of the average juror (People v Keindl, 68 NY2d 410, 422; People v Cintron, 75 NY2d 249, 267). The evidence was not offered to show that the assaults took place (People v Taylor, 75 NY2d 277, 293), but was relevant to explain why the victim had difficulty pinpointing dates, failed to initially disclose the abuse, and her reaction to the courtroom procedures. We further note that defendant’s objection to this testimony, raised for the first time on appeal, is unpreserved as well as being substantively without merit.
We have examined defendant’s remaining claims and find them to be without merit. Concur — Carro, J. P., Wallach, Asch and Nardelli, JJ.