The study by Aberdeen University showed that a woman's age affects the outcome of every single step of IVF treatment. It is the first study of its kind to break down failure rates for each stage of IVF for different age groups.
Researchers examined data from 121,744 women from across the UK who underwent their very first cycle of IVF between 2000 and 2007 using their own eggs. They found that women's chances of having a baby following IVF start to decline by their mid-30s but from 37 onwards these go very rapidly downhill.
Even after a pregnancy has been confirmed, women aged 38-39 were 43% more likely to have a miscarriage than women aged 18-34, while women aged 40-42 were almost twice as likely to lose the baby as 18 to 34-year-olds.
Professor Siladitya Bhattacharya, professor of reproductive medicine at Aberdeen University, led the research. He said: "IVF comprises a number of key steps, each of which has to be successfully achieved before the next stage can be attempted. We found that age impacted on every single hurdle that has to be overcome during the emotional rollercoaster that is IVF.
"There is no point during an IVF treatment - even in women who have done well in a preceding stage - when age ceases to matter. Age has the capacity to increase the risk of treatment failure even in women who respond to hormonal treatment, have eggs harvested and embryos replaced.
"We hope our study provides a more accurate and dynamic way of predicting a couple's chances of treatment failure as they negotiate each step of IVF."