It’s a big discovery that every woman hoping to get pregnant through in vitro fertilization could benefit from. A new calculator can help a couple measure their odds of success with IVF before they even start the treatment, which could prevent many failed IVFs from ever happening and save many people time, expense and heartache.

Doctors typically avoid estimating a couple’s changes of having a baby before the first cycle of IVF as they must evaluate the quality of many factors, ranging from sperm to eggs to characteristics like age and weight of the mother, which makes IVF a big gamble for a lot of people. With this new pre-treatment calculator, however, women can estimate what their chances are before the first cycle, and even after the first cycle the calculator can be further adjusted for greater accuracy, according to a BMJ statement.

A total of 29 percent of women had a baby after one cycle, and 43 percent delivered after six cycles. The study was based on data from 113,873 women with 184,269 complete IVF cycles.

The authors conclude: “These are the first models to predict individualised chances of live birth over a course of complete IVF cycles. The results are relevant not only for individual couples and their clinicians, but also for funders and policy makers in determining access to state or insurance funded IVF.”