Reproduction study of caffeine administration to male Osborne-Mendel rats

The potential for caffeine, administered twice daily by gavage in a total dose of 40 or 80 mg/kg/day, to adversely affect the reproductive performance of male rats was investigated. Treatment was continued through 3 wk of serial mating; mating and dosing were terminated concurrently, after which the sires were autopsied and their testes weighed. Controls were treated similarly with distilled water. Significant dose-related differences were detected for sire body weight, but not for testes weight. The majority of the significant effects on the offspring were for those born to the low-dose sires. Statistically significant differences were sporadically detected for the number of pups born and their body weights and survival; however, these differences were not consistently detected in either a dose- or temporal-related fashion. Thus, caffeine appears to have little potential to produce adverse reproductive effects when administered by gavage to male rats at the levels tested in this study.