Infertile couples who fail to conceive by IVF could be helped to decide whether to try again by a test that assesses their chances of having a baby at the second attempt, U.S. researchers revealed in a report Monday.

The technique, which uses data gathered during a first fertility treatment cycle to predict success in a second, offers a more accurate prognosis than standard methods, according to research.

If the findings can be independently confirmed, the test could benefit thousands of couples who do not get pregnant the first time they have IVF, and are then faced with a difficult decision about trying again.

It would allow a more informed choice about whether their prospects of having a baby justify the physical and emotional stress and the financial cost.

About 7.3 million American women suffer from infertility, according to the U.S. Centers for Disease Control and Prevention, based in Atlanta.

“For some of the patients we may be able to reassure them and help them move forward and do another cycle if they have good odds," Lynn Westphal, of Stanford University in California, a member of the study team, said. "For other patients, if they’re in a poor category, we’ll help them move on to consider better options.”

To develop the test, the Stanford team collected information on 52 clinical variables for 1,676 women treated for the first time at its IVF center between 2003 and 2006.

Of the 1,196 women who did not have a live birth after the first cycle, 732 went on to be treated again. The scientists used data from their first cycles to refine age-based success predictions for their second attempts.

The results, published in the journal Proceedings of the National Academy of Sciences, found that adding some of this information into a computer model produced more accurate predictions than age alone. Particularly important factors included the number of eggs and embryos produced during the first cycle, the rate of embryo development and the amount of hormonal drugs used.