It is the natural expectation of any couple planning a pregnancy that, sooner or later, they will have a family. For many couples this happens later rather than sooner. 

Doctors expect couples to have been `trying for a baby` for an average of six months before conceiving, and will not consider it a problem worth further investigation until you have been trying for about 18 months without success. 
Even then, there is a strong chance that you will conceive naturally and without medical intervention. 

Approximately 70 per cent of couples have conceived after one year of first trying; 80 per cent after 80 months; and 90 per cent after two years. Sadly, at this point around 10 per cent of couples discover they are infertile, and a seemingly endless process of investigations begins.

It is estimated that one-third of infertility problems are due to the female partner, one-third to the male partner and the remaining one-third to a combination of both partners. Tests to establish the origin of your infertility, and the best route towards treating it, should be completed within a few months.

• Sperm defects.
• Ovulatory failure.
• Damaged fallopian tubes.
• Endometriosis.
• Coital failure.
• Mucus dysfunction.

However 28 per cent of infertile couples fall into the category of unexplained fertility.  

Where the male partner's sperm cannot be used it may be possible to use that of a sperm donor, and several hundred children are conceived in this way every year. The main considerations for the couple are the impact on the male partner's ego, and the effects they think donor insemination will have on the child.