Common wisdom seems to indicate that menopause signals the fact that a woman’s ovaries have “run dry” - in other words, menopause occurs when there are no more eggs. My mother used to joke about how she was “the last egg,” because she was born when her mother was her mid-40s, and after my grandmother gave birth her period never started again.
However, with a little bit of thought the idea that women menstruate until they run out of eggs makes no sense. If that were true, women who cease to menstruate for extended periods for any reason (being pregnant, using ovulation-supressing birth control, ceasing to ovulate due to low weight, etc.) but who then resume ovulating would have very late menopause.
In reality, this is not the case. Consider a woman who used “the pill” for 10 years from her teens to mid-20s, who then went on to carry six pregnancies to term. This would delay her menopause by 14+ years if she still had to release her eggs 1x/month for her menstruation to cease, so we would expect her to hit menopause at an average age of 65 (the “normal” age of 51 + 14 years of non-ovulation).
So what IS the relationship between eggs in the ovaries and menopause? Do the eggs die at some point and that is when menopause hits, regardless of how many eggs are left?