What Causes Female Infertility?

Causes of Failure to Ovulate

Ovulatory disorders are one of the most common reasons why women are unable to conceive, and account for 30% of women's infertility.  Fortunately, approximately 70% of these cases can be successfully treated by the use of drugs such as Clomiphene and Menogan/Repronex. The causes of failed ovulation can be categorized as follows:

(1) Hormonal Problems
      These are the most common causes of anovulation.  The process of ovulation depends upon a complex balance of
      hormones and their interactions to be successful, and any disruption in this process can hinder ovulation.  There are three
      main sources causing this problem:

(2) Scarred Ovaries
      Physical damage to the ovaries may result in failed ovulation. For example, extensive, invasive, or multiple surgeries, for
      repeated ovarian cysts may cause the capsule of the ovary to become damaged or scarred, such that follicles cannot mature
      properly and ovulation does not occur.  Infection may also have this impact.

(3) Premature Menopause
      This presents a rare and as of yet unexplainable cause of anovulation.  Some women cease menstruation and begin
      menopause before normal age.  It is hypothesized that their natural supply of eggs has been depleted or that the majority
      of  cases occur in extremely athletic women with a long history of low body weight and extensive exercise.  There is also
      a genetic possibility for this condition.

(4) Follicle Problems
     Although currently unexplained, "unruptured follicle syndrome" occurs in women who produce a normal follicle, with an egg
     inside of it, every month yet the follicle fails to rupture.  The egg, therefore, remains inside the ovary and proper ovulation
     does not occur.

Causes of Poorly Functioning Fallopian Tubes

Tubal disease affects approximately 25% of infertile couples and varies widely, ranging from mild adhesions to complete tubal blockage.  Treatment for tubal disease is most commonly surgery and, owing to the advances in microsurgery and lasers, success rates (defined as the number of women who become pregnant within one year of surgery) are as high as 30% overall,
with certain procedures having success rates up to 65%.  The main causes of tubal damage include:

(1) Infection
     Caused by both bacteria and viruses and usually transmitted sexually, these infections commonly cause inflammation
     resulting in scarring and damage.  A specific example is Hydrosalpnix, a condition in which the fallopian tube is occluded at
     both ends and fluid collects in the tube.

(2) Abdominal Diseases
      The most common of these are appendicitis and colitis, causing inflammation of the abdominal cavity which can affect the
      fallopian tubes and lead to scarring and blockage.

(3) Previous Surgeries
     This is an important cause of tubal disease and damage.  Pelvic or abdominal surgery can result in adhesions that alter the
     tubes in such a way that eggs cannot travel through them.

(4) Ectopic Pregnancy
      This is a pregnancy that occurs in the tube itself and, even if carefully and successfully overcome, may cause tubal damage
      and is a potentially life-threatening condition.

(5) Congenital Defects
      In rare cases, women may be born with tubal abnormalities, usually associated with uterus irregularities.


Approximately 10% of infertile couples are affected by endometriosis.  Endometriosis affects five million US women, 6-7% of all females.  In fact, 30-40% of patients with endometriosis are infertile.  This is two to three times the rate of infertility in the general population.  For women with endometriosis, the monthly fecundity (chance of getting pregnant) diminishes by 12 to 36%.  This condition is characterized by excessive growth of the lining of the uterus, called the endometrium.  Growth occurs not only in the uterus but also elsewhere in the abdomen, such as in the fallopian tubes, ovaries and the pelvic peritoneum.  A positive diagnosis can only be made by diagnostic laparoscopy, a test that allows the physician to view the uterus, fallopian tubes, and pelvic cavity directly.  The symptoms often associated with endometriosis include heavy, painful and long menstrual periods, urinary urgency, rectal bleeding and premenstrual spotting.  Sometimes, however, there are no symptoms at all, owing to the fact that there is no correlation between the extent of the disease and the severity of the symptoms.  The long term cumulative pregnancy rates are normal in patients with minimal endometriosis and normal anatomy.  Current studies demonstrate that pregnancy rates are not improved by treating minimal endometriosis.

Additional Factors

(1) Other variables that may cause infertility in women:

(2)  Behavioral Factors:
       It is well-known that certain personal habits and lifestyle factors impact health; many of these same factors may limit a
       couple's ability to conceive.  Fortunately, however, many of these variables can be regulated to increase not only the
       chances of conceiving but also one's overall health. (3)  Environmental and Occupational Factors:
       The ability to conceive may be affected by exposure to various toxins or chemicals in the workplace or the surrounding
       environment.  Substances that can cause mutations, birth defects, abortions, infertility or sterility are called reproductive
       toxins.  Disorders of infertility, reproduction, spontaneous abortion, and teratogenesis are among the top ten work-related
       diseases and injuries in the U.S. today.  Despite the fact that considerable controversy exists regarding the impacts of
       toxins on fertility, four chemicals are now being regulated based on their documented infringements on conception.
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