Female Fertility Facts

Adults understand the birds and the bees; however, not many people truly understand the most important part in making a baby—fertility. Understanding the basics regarding female fertility and the risk factors that can lead to infertility are key to avoiding potential future frustration. Additionally, knowing what time one's individual " Biological Clock" says, is very important. This is easily determined through simple screening and it is highly recommended that women aged 20 and older who wish to bear children should periodically complete such fertility screening and testing.

Infertility is a disease of the reproductive system and impacts men and women equally. Recent studies estimate that about 1 in 6 child-bearing aged couples in the United States suffer from infertility. Just from the states served the most by MCRM (Missouri, Illinois, Oklahoma, Kentucky, Kansas and Arkansas), it is estimated that approximately 715, 000 women of child-bearing age suffer from a form of infertility.

Some of the causes of infertility in females include:

  • Ovulation Disorders (PCOS, Hypothalamic Dysfunction, Low Ovarian Reserve)
  • Fallopian Tube Damage
  • Endometriosis
  • Uterine or Cervical Causes

Understanding the Biological Clock

Do You Know What Time It Is?

The "Biological Clock" refers to the concept of "ovarian reserve" or simply the total number of folliclesone has left on the ovaries.

A woman has the MOST eggs she will ever have when she is in her mother's uterus at about 20 weeks of pregnancy. (i.e. roughly 20 weeks before she is even born). There are approximately a total of seven million immature eggs at this time. The eggs are continuously being lost from that point on, even though there is no menses. The number of eggs a woman has at birth then is approximately two million. By the time a woman has her first menstrual cycle, on average at age 11-12 years, she has lost approximately 75% or more of the total number of eggs she started with leaving an estimated 400, 000 eggs total in the ovaries. From that point on, every menstrual cycle, if the cycles are regular, the woman produces a group of early eggs referred to as a cohort of antral follicles. This is the number of follicles that have potential to grow and ovulate in any one menstrual cycle. Typically, of course, only one from the cohort does gown and ovulate. The rest die off.

There is a certain number in this cohort of antral follicles each month. A woman of young age will have a larger number in the cohort than an older woman. The number of antral follicles in this cohort is relatively stable from month-to-month and does not fluctuate substantially. However, over a period of several months or a year, the number of follicles in the cohort can be expected to decrease. That is to say, that over time, the number of follicles/eggs in the cohort will decrease. This decrease is the "biologic clock', also referred to as " ovarian aging ". It is inevitable that the number of follicles goes down with time, one cannot change this from happening.

After the age of 35, the rate at which the number of follicles are lost increases. Thus, after the age of 35, on average, a woman will lose eggs faster than she did previously, at a younger age. Ultimately, on average, around the age of 50, there will be no follicles or eggs left in the cohort. This is referred to as menopause .


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