Pregnancy During Perimenopause
A 30-year-old woman has a 20 percent chance of getting pregnant in any given month. At 40, that figure plummets to 5 percent. By the time you reach 45, your chance of a healthy pregnancy using your own eggs is 1 percent. That’s why women over 35 looking to conceive are encouraged to see a reproductive endocrinologist after just 6 months of trying, while younger couples are encouraged to try on their own for a full year.
source: https://www.healthline.com/health/menopause/pregnancy#3