Long-term effects of delayed motherhood in mice on postnatal development and behavioural traits of offspring

BACKGROUND: Some epidemiological evidence tentatively suggests that children born to older parents may have lower intellectual development and maturity than children whose parents are younger. This study aims to analyse the long-term effects of delayed motherhood in mice on postnatal development and behavioural traits later in life. METHODS: Hybrid females, either at the age of 10 weeks or 51 weeks, were individually housed with a randomly selected 12-14 week old hybrid male. After a postweaning resting period of 1 week, dams were caged again with a new randomly selected 12-14 week old male. This sequence of events was repeated until old females reached the end of their reproductive life. RESULTS: Delayed motherhood in mice not only had negative effects on reproductive potential but also on preweaning development of offspring as evidenced by higher mortality, retarded sensorimotor integration and lower body weights as well as on behavioural traits of young adult offspring including decreased spontaneous motor activity, lower step-through latencies in the retention trial of a passive avoidance behaviour test, and no changes in escape latencies throughout five daily sessions in a Morris water maze test. CONCLUSION: Advanced maternal age at conception may influence preweaning development and learning capacity of offspring in the mouse model.