American woman give birth to their first child after the age of 35, which is another reason for dramatic increase in medical interventions for infertility in the past 10 years. The main reason women give birth so late is the fact of late first marriages, liberalization of abortion, awareness of STDs, and the last, but not the least important factor is the socio-economic status. As said above, numerous medical studies have proved that woman s fertility dramatically decreases after age 35, since every woman is born with the unique supply of eggs during her lifetime until they stop producing them in menopause, while the effect on male fertility is only minimal, and men produce continuously sperm throughout their lives. Woman has the most fertile eggs in her teens until her late 20's.
When woman reaches 30's her eggs have a potential of fertilization, but it is decreased. Reason for this is chromosomal injuries that are much more common with increased woman s age. Additionally, age is also related to increased number of miscarriages, especially when approaching the age of 40. This problem is mostly related to chromosomes and cellular machinery of eggs, there is little it can be done to turn back this biological clock. For example, in woman younger than the critical age of 35 the majority of ovulated eggs have normal composition of chromosomes, but as woman gets older than 35, the increasing number of her eggs get abnormal with the main reason lying in the natural process of aging when egg quality and quantity declines.