Five-cycle limit to IVF success
Women under the age of 35 who persevere with in-vitro fertilisation have a one-in-two chance of having a baby, according to a world-first study into the cumulative success of the treatment.
But the "take-home baby rate" - based on couples who have up to five cycles - falls to 15 per cent for women in their early 40s resorting to IVF.
The report by the University of NSW national perinatal epidemiology and statistics unit shows that one-quarter of Australian women who had IVF in 2011 were over 40, with some aged 54.
A decade earlier they made up only 14 per cent of patients.
The researchers found there was little additional chance of pregnancy after the fifth cycle, regardless of age, and said the results could help couples decide on whether to have fertility treatment and how many cycles.
Across all age groups, the chances of having a baby was 21 per cent after the first cycle, rising to 40 per cent after five cycles, but it barely increased after that.
Elizabeth Sullivan, who heads the research unit, said statistics from 35 fertility clinics showed more than half of women under 35 had a baby within five rounds of IVF.
"This is a great result and shows the benefit of getting treatment early," she said.
"The other good news is we expect to see the cumulative success rates increase as women who may have only had one or perhaps two cycles in our study timeframe return for further treatment and get pregnant."
Professor Sullivan said though more than 90 per cent of women having IVF had fewer than five cycles in 2009-11, there were 264 who had 10 or more cycles.
University of WA professor of reproductive medicine Roger Hart said a small but similar WA study a few years ago found that IVF couples had on average only three cycles, even though their chances of having a baby increased with each successive cycle for at least the first five cycles.
It concluded the success of IVF could be improved if women, particularly those over 35, had more cycles.
