To mate or not to mate: a retrospective analysis of two-generation studies for evaluation of criteria to trigger additional mating in the extended one-generation design.

An extended one-generation study is proposed to replace the standard two-generation study, and would eliminate breeding F1 animals unless triggered by effects on parental reproduction or pup development. Nine two-generation studies in rats were reviewed to determine whether reproductive or developmental toxicity was more pronounced in the F2 generation… (More)