To investigate the effect of exercise during pregnancy on anxiety and depressive-like behaviors in adolescent male mice offspring and the underlying mechanisms. Methods: Pregnant female mice were subjected to controlled wheel running (1 h/d) starting from day 2 of pregnancy until the day of birth. Maternal behavior was assessed weekly after delivery. Adolescent male offspring (4 weeks postpartum) underwent 2 weeks of chronic restraint stress for 3 hours daily before behavioral testing, and hippocampal tissue was collected to measure levels of neuroinflammation and apoptosis. Results: Prenatal exercise increased maternal behavior in pregnant female mice, reduced anxiety and depressive-like behaviors in adolescent male offspring after chronic stress, and inhibited apoptosis and NLRP3-associated neuroinflammatory activation in the hippocampus. Conclusion: Wheel running during pregnancy increased maternal behavior in lactating female mice, reducing anxiety and depressive-like behaviors in adolescent male offspring after chronic stress, possibly by inhibiting hippocampal neuronal apoptosis and NLRP3 inflammasome-related neuroinflammatory activation.