Causes of Infertility

There are many possible causes of infertility. A single cause may not be linked to either the man or the woman. Often the problem stems from a combination of factors in either or both partners. You and your partner will be diagnosed as a couple to determine the best treatment for you.

Approximately 15% of couples have difficulties with conceiving at their first attempt. Most authorities define these patients as primarily infertile if they have been unable to achieve a pregnancy after one year of unprotected intercourse. Conception normally is achieved within twelve months in 80-85% of couples who use no contraceptive measures, and persons presenting after this time should therefore be regarded as possibly infertile and should be evaluated.

Data available over the past twenty years reveal that in approximately 30% of cases pathology is found in the man alone, and in another 20% both the man and woman are abnormal. Therefore, the male factor is at least partly responsible in about 50% of infertile couples.

Infertility in the Man

A man may be infertile because he does not have enough sperm; because the sperm are not active enough; because the passage, or vas deferens, is blocked; or because of problems with ejaculation.

A number of factors can cause or contribute to male infertility:

• Sexually transmitted diseases, such as gonorrhea or chlamydia
• Fevers and infections, such as mumps occurring after puberty
• Surgery of the reproductive tract, such as that for undescended testes, hernia repair, disorders of the prostate gland, or cancer
• Damage to the vas deferens, most often by vasectomy
• Varicose veins in the scrotum (varicocele)
• Use of certain drugs, such as those for depression or high blood pressure
• Exposure of the testes to high temperatures, such as those that result from the wearing of tight, unventilated clothing; excessive use of hot tubs; or conditions in the workplace
• Use of tobacco, marijuana, or alcohol
• Medical conditions, such as diabetes
• Genetic or hormonal problems
• Injury to the testes, such as that resulting from physical trauma or exposure to radiation, can also cause infertility in the man.

Infertility in the Woman

A woman may be infertile because of hormone imbalances or problems in the reproductive tract.

Factors that can cause or add to female infertility include:

• Hormone levels that prevent the release of an egg from an ovary or the implantation of a fertilized egg in the lining of the uterus
• Extra weight (more than 30% over her ideal body weight), which may cause problems with ovulation
• Scarring or tumors of the uterus or defects of the uterus present from birth
• Too little or poor-quality cervical mucus, sometimes due to surgery or other treatment
• Endometriosis-a condition in which tissue like that normally lining the uterus (the endometrium) is found outside the uterus
• Adhesions-bands of scar tissue from previous surgery, endometriosis, or infections that bind together tissues inside the abdomen
• Infections such as pelvic inflammatory disease (PID), a severe infection of the female reproductive organs that may be caused by sexually transmitted diseases such as gonorrhea or chlamydia; or appendicitis, which can result in scarring of the internal pelvic organs
• Production of antibodies that attack her partner's sperm
• Medical conditions, such as thyroid disease or diabetes
• Genetic conditions such as Turner's syndrome, in which a woman has only one X chromosome and may not completely develop breasts or pubic hair
• Use of tobacco, marijuana, or alcohol