In 1995-6, 18.5% of all IVF treatment cycles resulted in a pregnancy and 15% of treatment cycles resulted in a baby. For comparison, the average monthly chance of conceiving for a fertile couple having normal intercourse is 20-25%.

There are a number of factors that may affect the outcome of IVF treatment. Research carried out on the data held on the HFEA register has shown that the main factor that influences the outcome of the treatment is the age of the woman whose eggs are used in treatment. Women under 35 using their own eggs have a 17-18% chance per IVF cycle of having a baby. Your chances drop after that: 13% chance for 35-39 year olds, 5.5% chance for 40-44 year olds, and 2.2% chance for those over 45. Older women have a much higher likelihood of success if they use donated eggs - between 16-18%.

Other factors that influence the outcome of treatment include the duration of infertility, the woman's previous ability to conceive, and the quality of the sperm.

IVF pregnancies are more likely to result in a miscarriage than normal pregnancies. This may be because women undergoing IVF are older and are more likely to have other fertility problems than the rest of the population.

If the treatment does not lead to a pregnancy then there are several options. After discussion you may decide to try again with IVF, to try a different type of infertility treatment or to have no further treatment. The staff at the clinic and your GP or consultant will be able to offer advice and support. Counselling can be useful at this stage.