Study predicts speed of female biological clock
February 25th, 2010 Posted in News95% of women have lost as much as 88% of their original reserve of eggs in their ovaries by the age of 30 new research has shown. Collaborative efforts at the University of Edinburgh and the University of St Andrews employed mathematical models to predict the dynamics of the ovarian egg reserve, and its changes with age.
The human ovary contains a fixed number of eggs which is established before birth. This store declines with age, becoming depleted by the age of 50-51. Analysis using data from women in the UK, US and Europe, shows egg recruitment increases from birth till age 14 afterwhich it declines with age until the menopause. By the age of 40 as little as 3% of the original egg reserve remains.
The study also predicts that 81% of variance between women in their egg reserve is due to age alone, with the remaining 19% resulting from factors other than age e.g. smoking, BMI, and stress. The study, published in PloS One journal, speculates that as age increases, factors other than age become more important in determining the rate of egg loss. “By understanding the dynamics of ovarian reserve, we can predict which children and young people treated for cancer are most at risk of an early menopause,” states Dr. Hamish Wallace, consultant oncologist at the University of Edinburgh. It is hoped that a better understanding of the dynamics of human ovarian reserve will provide a more scientific basis for fertility counselling.
- Sobia Raza
