Abstract
Caffeine was given to pregnant mice subcutaneously at doses of 10 and 40mg/kg body weight, on the last four days of pregnancy. Subsequently, effects on the behaviour of their cross-fostered male offspring were studied using the "standard opponent" test. Significant decreases in threat, attack, displacement and number of fights, as well as an increase in latency to attack, were observed in the offspring exposed to the higher dose. Thus, excessive consumption of caffeine during pregnancy appears to have a lasting influence on the behaviour of offspring via a direct in utero action.