consequences of age on the fertility of women

A woman’s age is one of the most critical factors when it comes to becoming pregnant.

Female fertility peaks in the early twenties, and declines thereafter. After the age of 35, fertility decreases dramatically (such that a 35-year-old woman has only half the chance of a twenty-year-old of becoming pregnant); and when a woman approaches her forties the chance of falling pregnant is greatly diminished to approximately 10% of the chance of a 20-year-old. Put another way, a 37-year old woman has approximately a 25% chance of fertility problems; a woman of 41 years, 50%, and a woman of 43 years has a 75% chance of a fertility problem.

The reason age is so critical in relation to female fertility is explained by the fact that the quantity as well as the quality of the eggs (ova) decrease with time.

Before a woman is even born, her body produces a supply of egg cells - about seven million - that she draws on throughout her life. The ova are immediately enshrined by a special layer of supporting cells and enter a phase of dormancy, in which they remain until they resume their development - perhaps 40 years later. But from birth onwards, no new eggs are produced.

As the ova leave their state of rest and resume their development, there is a steady decrease in the number that is in reserve in the ovaries. By birth, the number of ova has already fallen dramatically to about one million. It falls to about 300,000 by the time a female reaches puberty, and then declines more gradually throughout a woman’s reproductive life. Eventually, there comes a time when the store of ova runs dry; and menstruation ceases. At this point, the woman has experienced the menopause. In the years immediately before the menopause, many changes arise; many women experience a change in the length of their menstrual cycles, or heavier periods.

Nor is it just the actual number of eggs present in an older woman that affects her fertility. There is also a greater chance that eggs from an older woman may either not contain all of the chromosomes, or may contain too many. Many of these abnormal eggs never become fertilised or do not implant and therefore don’t result in a pregnancy, or do but are not viable leading to miscarriage. Additionally, the foetus has a higher chance of congenital defects due to defective chromosomes. Due to this, prenatal examinations are warranted for pregnant woman of 36 years or older.

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consequences of age for pregnancy

The age of a woman is also important for the smooth running of the pregnancy itself.

It is a good idea to be aware of the risks associated with older pregnancy beforehand. You can find out more about these in Pregnancy in women > 35 years.

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