I started my periods when I was 11, I never took the pill, and I have never missed a period. I am now 41. I read that the average number of eggs a woman produces is 400, and if you figure out how many times you've ovulated, you can calculate when menopause will begin. I've had about 360 ovulations and that leaves only about three more years of ovulating. Is this theory a myth or should I expect menopause soon?

Gene

Great question! The maximum number of eggs we ever carry inside us is about 6-7 million, and we reach that maximum at about 20 weeks of gestation -- that is, about four and a half months before we are even born! By the time we are born, that number has already dropped to 2 million or less, and it continues to decrease, so that by puberty we have about 300,000 eggs. Between puberty and menopause, for every egg that is actually ovulated, many others will start the process and fail. For every egg ovulated, it's estimated that up to 1,000 are lost along the way. An average woman will ovulate less than 500 times in her reproductive lifespan.

Many factors influence the age of menopause. The average age is 51, and has remained the same over at least the last 100 years. Life expectancy in 1850 was only 40 (!) and now is around 79 for women, so we are living an increasing proportion of our lives in menopause. There is no relationship between the age of onset of periods and the age of menopause. Women who live at high altitudes, cigarette smokers, women who have had hysterectomies and very thin women tend to go into menopause earlier. There is probably some familial tendency to go into menopause at a certain age as well. Certain autoimmune diseases may contribute to premature ovarian failure and early menopause.

So, the bottom-line answer to your question is "no" -- we cannot predict the age of menopause based on how many ovulations a women "should" have in her lifetime. You will go through menopause when you go through menopause.