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Jun 07, 2006
Fertility: Best age for man & woman
by SirGan
 Fertility issue has been a subject of many discussion and controversies all through the history and women were always worried about probable fertility peak and the best time for reproduction! Although age is not an absolute barrier to pregnancy, the proven fact is that female fertility decreases with age, while the situation with men is a bit different! Women are born with all the eggs that they will ever have in their lives while, men, on the other hand, make fresh sperm continuously throughout their whole lives.Reproduction – factsWhat exactly is reproduction! Reproduction is a most important function of an organism's life history, and all other vital processes, including senescence and death, are shaped to serve it. There are different models of reproduction! The most common are semelparous and iteroparous model of reproduction. Semelparous organisms reproduce by a single reproductive act. Annual and biennial plants are semelparous, as are many insects and a few vertebrates, notably salmon and eels. Iteroparous organisms, on the other hand, reproduce recurrently over a reproductive span that usually covers a major part of the total life span. Human fertility depends on factors of:
Male and female reproductive systemAlthough most people knows this- the fact is that women are born with a fixed number of eggs about 400,000 eggs. There wouldn’t be any problems if this situation would stayed like this. But this number decreases even during early childhood, bringing the number closer to 300,000 eggs by the time a woman reaches puberty.
Over the next 35 to 40 years of reproductive life, only 400 to 500 eggs will ovulate and at menopause only a few hundred will remain. During the fourteenth week of fetal growth, women’s eggs form in her ovaries, where they will remain until puberty.
Situation with men is a bit deferent! However, the truth is that men continually produce sperm throughout their lives.
Fertility and ageAlthough there is still some disagreement over the issue, most fertility experts now agree that fertility decreases with age. There are several pieces of evidence that point to this fact. Most people believe that nothing can interfere with man’s ability to produce sperms because they can't “run-out” of it! Although men are not born with a fixed number of sperm, age and health can affect a man's ability to reproduce. The fact is that there is a decline in testosterone levels as a man ages, as well as sperm motility and decreased sexual activity. The major factors in male reproductive health include the quality of the ejaculate and the frequency of intercourse.
Why does Fertility Decrease?The fact is that for a long time now it was not known why fertility decreases with age.
Research has focused on two areas: aging of the uterus versus aging of the eggs. Now some modern technologies of egg donation has enabled experts to look at these factors separately. If fertility decreases because an older woman's uterus is less capable of carrying a pregnancy, then using younger eggs shouldn't produce very many pregnancies in older women. But- several researches have proven exactly the opposite thing.
Women in their forties, fifties, and even sixties can all achieve very high pregnancy rates with egg donation. This is proof that fertility decreases with age due to aging of eggs and chromosomes, not aging of the uterus, like some though it is.
Fertility monthly cyclesAlthough most people don’t know much about this- the fact is that both women and men have hormonal cycles which determine both when a woman can achieve pregnancy and when a man is most fertile.
The female cycle is approximately twenty-eight days long, but the male cycle is variable. Women ovulate at about the fourteenth day of their cycle, this obviously being the most fertile time for females.
Men can ejaculate and produce sperm at any time of the month, but their libido dips occasionally, which scientists guess is in relation to their internal cycle.
Increased risk of miscarriage with ageSeveral researches has been conducted on this subject and there are some conclusions! It has been proven that, in addition to the lower chance of becoming pregnant, as women age they also have a higher chance of miscarriage. What are the reasons for this? The fact is that it takes approximately 90 days for a sperm to reach maturity. This is an extremely important difference between the sexes. It is proven that the longer an egg sits in the ovary, the more likely it is to develop abnormalities in its chromosomes. This is because all the time some mutations are happening inside the ovarian cell. Some chromosomes are replacing or loosing some parts and this could be the problem if the process is being active for too many years! If an egg with abnormal chromosomes is fertilized, then the chances are greater that the resulting pregnancy will end in miscarriage. Statistic data are saying that a young woman has only a 12-15% chance of having a miscarriage each time she becomes pregnant, while a woman in her 40s has, however, a 50% risk of miscarriage.
Fertility tests
There are several tests which are made to determine the fertility! The most important test which are made to determine a woman's fertility level is a blood test called FSH- Follicle Stimulating Hormone. This hormone is made in a gland near the brain, called the pituitary. It is the most important hormone responsible for the cyclic development of eggs every month. As a woman's eggs become less capable of producing a pregnancy, the levels of follicle stimulating hormone begin to rise. Therefore, logically FSH generally increases in women as they get older. Women who have gone through menopause have very high levels of FSH. This can be done via simple blood test! The blood should be drawn on the third day of the menstrual cycle. What are the normal levels?
What Does A Semen Analysis Analyze?The complete semen analysis includes:
Normal findings are:
Treatment of infertility
Many physicians use fertility medications to try to increase the chance of pregnancy. There medications should increase the number of eggs that develop in a given month, thus enhancing the chance that at least one of them might be able to be fertilized and develop into a viable pregnancy.
Others have advocated in-vitro fertilization (IVF) as a means to achieve pregnancy in such cases.
Currently, the only consistently successful method to improve pregnancy rates in women with age-related infertility is egg donation. The indications for egg donation include:
Tips for enhancing reproductive health
It is proven that tobacco smoking is linked to low sperm counts and sluggish motility. As a meter of fact- recent findings suggest a 64% increase in miscarriage when both partners smoke or when just the man smokes.
Long-term use of marijuana in men results in a low sperm count and sperm that exhibit abnormal patterns of development.
Chronic alcohol abuse damages the intricate plumbing of the male reproductive system, reducing a man's ability to produce normally formed sperm cells.
Men who exercise excessively may be reducing their sperm count due to the heat that builds up around the testicles during strenuous exercise.
Some groups of antibiotics have been shown to affect sperm quality temporarily by decreasing count and motility. These groups are nitro-furans (nitrofurazone or nitrofurantoin) and macrolides (erythromycin).
If a person is malnourished or not getting enough of the right foods and nutrients, sperm count could suffer.
Excessive heat in the scrotal area should be avoided in all causes. Hot tubs, saunas or anything that raises the temperature of scrotum, including overheated vehicles and hot work environments should be avoided.
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