A new "IVF calculator" can predict a couple's success of conceiving a baby, experts have said.
The tool, which can be used by doctors or people seeking fertility treatment, can estimate a couple's chance of having a baby before and after first IVF treatment, and over multiple cycles.
Writing in The BMJ, researchers led by the University of Aberdeen describe how the calculator could "help to shape couples' expectations".
It takes into account the age of a woman, how many years she has been trying to conceive, whether she has an ovulation problem, an unexplained fertility issue or whether there is a male fertility problem among other factors.
The tool is based on data from the Human Fertilisation and Embryology Authority (HFEA) which collects information on all licensed fertility treatments in the UK.
The researchers analysed data from all women who started IVF and intracytoplasmic sperm injection (ICSI) in the UK from 1999 to 2008 using their own eggs and partner's sperm.
They found that of 114,000 women who completed almost 185,000 cycles of treatment, 29.1% had a live birth following their first cycle.
And 43% had a baby following six cycles of treatment.
They found that the chances of a couple having a baby declined after the woman reached the age of 30 and decreased with increasing duration of infertility.
The data was then put into the calculator to predict IVF success.
For example, the calculator predicts that a 30-year-old woman with two years of unexplained infertility has a 46% chance of having a live birth from the first complete cycle of IVF and a 79% chance over three complete cycles.
:: The calcuator can be found at w3.abdn.ac.uk/clsm/opis.
Professor Adam Balen, chairman of the British Fertility Society, said: "This is an important paper which analyses the HFEA database to calculate prediction models for success based upon baseline characteristics and the data collected during the treatment.
"The database is huge and so the information gathered is clinically relevant.
"It is important to remember that treatment should be individualised to the patients' particular needs and profile and it can still be difficult to accurately predict the outcome."