The chances of pregnancy for a fertile young couple are about 25% per month. After 12 months of trying, approximately 80% of couples will have conceived. Approximately 15% of couples have difficulty achieving a pregnancy. It has been found that female factors are responsible for 40% of cases; male factors account for a further 40% & remaining 20% is a combination of male & female factors. Unexplained infertility affects 20-25% of infertile couples.