Effect of advancing maternal age on some histomorphological characteristics and other parameters of the offspring of wistar rats

Background: The average age of mothers at the time of first childbirth has been increasing over the past decades. Delayed motherhood comes with several adverse outcomes. Objective: We investigated the effect of advancing maternal age on some histomorphological parameters in the litters of female Wistar rats. Materials and Methods: Twenty-seven female rats (11–40 weeks old) were divided into three groups (young-, mid-, and old aged) of 9 rats each and mated with 12 male rats. The morphological parameters of the litters were obtained and a classic maze task was performed. Data were analyzed using the Statistical Package for the Social Sciences version 23 and values at P < 0.05 were considered significant. Results: The litters of young-age mothers were significantly fewer (5.0 ± 0.4) compared to litters of mid- (8.0 ± 0.3) and old-aged (11.6 ± 0.8) mothers. Sex ratio significantly increased as the maternal age increases. Litters of young-aged mothers committed more errors (3.4 ± 0.5) and took longer to complete the maze task (147.0 ± 24.9s) compared to litters of the other groups. However, the biomarkers of oxidative stress (OS) in the brain homogenate were worse with advancing maternal age. Histologically, there was a significant decrease in the external pyramidal layer width with advancing maternal age (8.18 ± 0.23 mm in young aged; 4.16 ± 0.09 mm in the old aged). Conclusion: Advancing maternal age has an enhancing effect on the litters' size, sex ratio, and cognitive abilities but a negative effect on OS and cortical width.