The Effect of Maternal Age on Ovulation, Corpora Lutea of Pregnancy, and Implantation Failure in Mice

This is the authors' abstract. We don't add key points for this paper.

Summary. C57B1 female mice aged 4 to 7 months (controls) and 8 to 9, 10 to 11, 12 to 13, and 14 to 15 months were mated and killed at 12 hr, 60 hr or 7½ days post coitum (p.c.). Corpora lutea were counted and evaluated in serially sectioned ovaries. Implantation sites were counted in the animals killed 7½ days p.c. The mean number of implantations in 10- to 11-month-old mice was less than in the control animals. This decrease was closely associated with morphological degeneration of corpora lutea of pregnancy. By 12 to 13 months of age most animals had neither implantation sites nor recognizable corpora lutea of pregnancy 7½ days after mating. These two changes were highly correlated and were not due to a decrease in the number of ovulations as determined by examination of the ovaries of animals killed 12 or 60 hr p.c. It was concluded that the initial decline in fertility with increased maternal age in this strain of mouse may be due to failure of luteal support of the uterus.