What is Infertility?

One in six Australian couples suffers from some form of infertility.

Infertility is most simply defined as the inability of a couple to achieve conception after a year of unprotected intercourse, or the inability to carry pregnancies to a live birth.

Infertility is shared equally among men and women, and in the vast majority of cases a physical problem can be diagnosed.

Failing to get pregnant can be the result of problems in either partner, or even both.

In about a third of all cases of infertility there is a physical problem with the female reproductive system. In about another third it is the reproductive system of the man which is not functioning as it should. The final third of infertility cases are either the result of both the man and the woman in a couple being less fertile than normal, or both couples are theoretically healthy but pregnancy just doesn't happen.

Causes of Female Infertility

The main conditions that contribute to female infertility include:

Abnormal cervical mucus - the cervix produces watery mucus just prior to ovulation that allows the sperm to reach the fallopian tubes and fertilize the egg. If the mucus is too thick it can prevent sperm from fertilizing the egg.
Abnormal ovulation - hormonal changes are usually the culprit during abnormal ovulation. Any number of factors can contribute to this condition, including premature menopause, polycystic ovarian syndrome (a condition in which an excessive amount of luteinizing hormone causes irregular ovulation), chemotherapy, tumors, infections, heavy exercise or dieting, and hyperprolactinemia (excessive production of prolactin).
Abnormal uterus - the ability of the uterus to accept implantation of an embryo and nurture it throughout the pregnancy can be affected by several factors, including fibroids, poor endometrial lining, and scarring or inflammation from endometriosis.
Abnormal pelvic area - abnormalities in the pelvic area such as blocked fallopian tubes or excessive scarring near the pelvic organs can cause infertility. There are a few conditions that contribute to this problem, including pelvic inflammatory disease, endometriosis, and pelvic surgery that results in excessive scar tissue.

Systemic illnesses, such as diabetes mellitus, neurologic disease, such as multiple sclerosis, and previous cancer treatment, such as chemotherapy or radiation, may be involved in the fertility problem. Past surgeries may also cause problems, specifically pelvic and bladder neck surgery. Previous hernia repair may also cause blockages.

Infections can affect fertility in several ways. Running a fever may periodically decrease sperm production, although this is usually short-lived. Mumps in adolescence may also cause problems with sperm production later in life. Sexually transmitted diseases, specifically Chlamydia and gonorrhea, may cause obstruction, as can any inflammatory condition within the testes or epididymides.

Gonadotoxins in the form of chemicals, medications (both prescription and over the counter), tobacco, alcohol, and illicit drugs, all affect sperm production to some degree. The duration and amount of exposure to the toxins often determines the severity and reversibility of the dysfunction.

Causes of Male Infertility

The main conditions that contribute to male infertility include:

Low sperm count (oligospermia) - low sperm count can be caused by a variety of factors, including stress, chemotherapy, high fever, lack of sleep, environmental toxins, over-heating, and other unknown causes.
Abnormal sperm motility - motility refers to the ability of the sperm to move. If the sperm are slow or if they are unable to move straight forward, they will have difficulty penetrating the egg.
Abnormal sperm shape - if the shape of the sperm is abnormal (normal shaped sperm should have an oval head and long tail) it will not be able to fertilize the egg.
Germ-cell aplasia - a condition in which sperm-producing cells develop abnormally.
Abnormal semen - a decreased amount of semen or semen that does not liquefy properly.
Tube blockages - blockages of the vas deferens or epididymis can be caused by varicoceles (enlarged veins that restrict the production of sperm in the testicles), gonorrhea, and chlamydia.
Sperm allergy - an immune reaction that produces antibodies that kill the sperm. This can occur in both men and women