Maternal and Paternal Age effects on Infertility

It has been long recognized the effect of age on female infertility. Recent evidence indicates that age also affects male infertility. Read on to find out more about how age affects female and male fertility.

Maternal Age and Infertility

Social and economic influences have forced women to delay the age at which they get pregnant. On the other hand, medical advances have also contributed that more and more young women are choosing to delay pregnancy until later on in life. In fact, some 20% of women are now giving birth to children after the age of 35. However, women cannot delay indefinitely the time to start a family as their “biological clock” is ticking without stop every day. The so-called biological clock can be explained as follows: women are born with a definite number of eggs in their ovaries. Even before birth they are losing eggs daily, this trend continues throughout their infancy, puberty, adult life and even during pregnancy. When they reach their mid to late 30s the quality and number of eggs is rapidly declining and so the probability of pregnancy either naturally or artificially. By the time the menopause arrives the probability of conceiving their own genetic children is less than 1%.

Pregnancy after 30

The chances of pregnancy for women decline slowly above 30 years of age. It decreases faster after 35 and at 40 the probability of pregnancy is less than 5%. After 45, however, experts say it is virtually impossible for a woman to conceive using exclusively her own eggs. The reason for this event is the lack of good quality eggs in the ovaries. The clinical evidence of ovaries devoid of eggs is the menopause.

With the decrease of eggs in the ovaries there is an increased and constant release of FSH. So measuring the amount of FSH in the blood indicates the probability of pregnancy. The doctor will order a test on the third day of her cycle to check for levels of FSH. The higher the FSH levels the lower the probability of conception with her own eggs. Ideally the FSH levels should be less than 10. Values consistently above 10 may be reason for concern.

Pregnancy in the menopause

The menopause is a clear indicator that there are no more eggs in the ovaries. Therefore, the chance of conception with the patient’s own eggs is virtually zero. Fortunately, the uterus keeps its ability to maintain and take a pregnancy to term. So for women with low probability of getting pregnant with their own eggs there is the option of eggs donated by known (a family member or a friend) or anonymous donors. The only contraindication for pregnancy may be more.

Sometimes age is not the only factor

For most women age is a good predictor of their probability of pregnancy. However, in some cases genetics and environmental factors may hasten depletion of eggs from the ovaries. Among these factors we have: premature ovarian failure (onset of menopause signs at an earlier age often this is genetically derived), radio or chemotherapy and surgical removal of the ovaries. That is why women over the age of 35 will generally undergo a fertility evaluation if they do not conceive after 6 months of having unprotected sex.

Paternal Age and Infertility

According to a recent report published in the European Journal of Epidemiology it appears that older fathers may increase the likelihood of the resulting children will die before adulthood. One of the reasons for this may be the decline in quality of sperm as men get older.

The research shows that children born from older fathers are more likely to suffer from a number of birth defects and conditions such as autism, schizophrenia or epilepsy. The majority of deaths were found to be caused by congenital defects that increased the risk of infant mortality, such as heart problems.

Children born to men aged 45 and above were found to be up to 88 per cent more likely to die before adulthood than those born to men aged between 25 and 29, the researchers found. The researchers looked at 100,000 children born between 1980 and 1996 using data taken from the Danish Fertility Database, and found that 831 of these had died before reaching the age of 13. Six hundred one (601) of these died in their first year. Similar results were found for men who fathered children while still in their teens, but could perhaps be explained by their mothers also being young and often therefore disadvantaged, say the researchers.

The risks of older fatherhood can be very profound, and it is not something that people are always aware of. People tend to be far more aware of the risks associated with older mothers, such as the increased prevalence of Down Syndrome, although it has also previously been shown that this may be affected by the father's age as well.

Genetic errors in sperm increase by half a per cent when a man reaches 40, by 2 per cent when he is 50, by 5 per cent when he is 60 and by 20 per cent by the time he is 80. On the basis of this, men around 40 ought to be thinking about the increased risk to their children, the same as women do.