Infertility Causes

What are the causes of infertility in women?

For a woman to conceive, certain things have to happen:

  • Intercourse must take place around the time when an egg is released from her ovary
  • The systems that produce eggs have to be working at optimum levels
  • Her hormones must be balanced.
  • Endometriosis or damage to the fallopian tubes (which may have been caused by infections such as chlamydia).
  • Being over or underweight for her age.

Female fertility declines sharply after the age of 35. Sometimes it can be a combination of factors, and sometimes a clear cause is never established when it is termed unexplained infertility.

How does age affect a woman's ability to have children?

More and more women are waiting until their 30s and 40s to have children. Age is an increasingly common cause of fertility problems. About one third of couples in which the woman is over 35 have fertility problems.

Aging decreases a woman's chances of having a baby in the following ways:

  • The ability of a woman's ovaries to release eggs ready for fertilization declines with age.
  • The quality of a woman's eggs declines with age.
  • As a woman ages she is more likely to have health problems that can interfere with fertility.
  • As a women ages, her risk of having a miscarriage increases.

What causes infertility in men?

Infertility in men is most often caused by:

  • Problems making sperm : producing too few sperm or none at all
  • Problems with the sperm's ability to reach the egg and fertilize it : abnormal sperm shape or structure or immunological problems prevent it from moving correctly
  • Sexual Dysfunction : Men with major problems of erection / ejaculation are unable deposit the sperms in the vagina.

Are there any other causes?

Other uncommon factors that can cause male as well as female infertility are:

  • Genetic Factors : A Robertsonian translocation in either partner may cause recurrent spontaneous abortions or complete infertility.
  • General factors : Diabetes mellitus, thyroid disorders, adrenal disease
  • Hormonal disturbances Kallmann syndrome, Hyperprolactinemia, Hypopituitarism
  • Environmental Factors : Toxins such as glues, volatile organic solvents or silicones, physical agents, chemical dusts, and pesticides.

What is combined infertility?

In some cases, both the man and woman may be infertile or sub-fertile, and the couple's infertility arises from the combination of these conditions. It may be that each partner is independently fertile but the couple cannot conceive together without assistance.

What is unexplained infertility?

In about 10-20% of cases the infertility investigations will show no abnormalities. In these cases abnormalities are likely to be present but not detected by current methods.

Possible problems could be that the egg is not released at the optimum time for fertilization, that it may not enter the fallopian tube, sperm may not be able to reach the egg, fertilization may fail to occur, transport of the zygote may be disturbed, or implantation fails.

It is increasingly recognized that egg quality is of critical importance and women of advanced maternal age have eggs of reduced capacity for normal and successful fertilization.