The reality is that human reproduction is a fairly inefficient process. For average fertile couples, the chance of fertilisation from any particular meeting of egg and sperm is about 80%., but by the time of the expected menstrual period, roughly half of these pregnancies will have already failed because the early embryos have not developed.

Many of these lost embryos are fundamentally abnormal and are unable to survive. In fact, the menstrual period might not even be delayed and many couples don’t realize that an early pregnancy has been lost. Even if a menstrual period is missed, in a quarter or more of pregnancies, the embryo still fails later.

Various clinical studies have calculated the chance of pregnancy among population groups who don’t use contraception, and indicate that probability of a live birth after exposure of egg to sperm in any one month averages about 1 in 5, or a 20% chance.

About 40% of cases the issue is attributable to the females while in 40% of cases the issue is traced back to the Male.

In about 10% of cases , fertility problems are linked to both partners.
The remaining 10% of infertility is unexplained.

Although there are many couples unable to have a child, infertility remains a personal issue. The suffering and despair which childlessness may bring to an otherwise fulfilling relationship is substantial. A modern fertility clinic offers a wide range of high-treatments but there are other important considerations too- the cost, the time required for the treatment, disappointment, the anxiety.

Estimates indicate that around one third of all infertility cases are the result of a male problem- most commonly related to the quality and quantity of sperm of the Male Partner. Because the reason for so much infertility is unexplained, male infertility- which is explained – has been described as ‘the largest defined cause of human infertility.

In recent years, specialist infertility clinics have also used in vitro fertilisation as a diagnostic test. Very often, healthy eggs fail to fertilise in the laboratory because of abnormal sperm function. Failed IVF therefore can provide more conclusive evidence of ‘male factor’ infertility. Causes Of Male Infertility