Natural Fertility, Natural Conception

15-20 percent of all couples have problems fulfilling their desire to have children.A woman’s highest natural fertility (fertility) is between the ages of 15 and 25, and declines steadily thereafter. Men’s natural fertility begins to decline slowly from the age of 40, but in some cases it can persist into old age. However, there is no talk of sterility until pregnancy does not occur within one to two years with regular sexual intercourse twice a week.

Natural fertility reduction

The natural fertility of a couple or woman directly affects the probability of pregnancy. The so-called expectancy of pregnancy is primarily dependent on the age of the oocytes (eggs) rather than the endocrine (hormonal) functioning of the ovary (ovary)). Male fertility may also decrease with age due to a decrease in sperm quality and a decrease in blood testosterone concentration. The natural fertility decrease is primarily determined by the age of the woman and the associated changes in the female organism.

Pregnancy expectancy

The normal pregnancy expectancy for a healthy young (between the ages of 20 and 30) couple is 0.3 per female cycle. This means that, on average, one pregnancy will occur over the course of three cycles, assuming the couple has regular sexual intercourse. However, the natural fertility of women decreases already from the 2nd decade of life. The chance of pregnancy occurring in a woman aged 35-39 is only half that of a woman aged 19-26. This is due to two main aspects:

  • Decrease in the amount of available oocytes (eggs) – The number of eggs available to a woman is determined during early embryonic development. These are approximately one million oocytes, one of which matures each cycle and allows pregnancy through ovulation (ovulation). However, during follicular maturation (egg maturation), several eggs perish, so the number of available cells decreases with each cycle. This also reduces the expectation of pregnancy with increasing age.
  • Oocyte (egg) aging process – Like any body cell, oocytes also age. This can possibly lead to a change or damage to the chromosomes (genetic material). Thus, more oocytes must mature until a healthy cell can implant in the uterus (womb). However, pregnancy can occur even though the genetic material is damaged.

The spontaneous defects in the aging process can cause the following chromosomal aberrations, which manifest as complex malformation syndromes:

  • Trisomy 21 – Down syndrome or mongolism.
  • Trisomy 18 – Edwards syndrome
  • Trisomy 13 – Patau syndrome (synonyms: Patau syndrome, Bartholin-Patau syndrome and D1 trisomy).

Thus, as a woman ages, not only does the likelihood of pregnancy decrease, but the incidence of malformation or miscarriage (miscarriage) increases.