08 November 2010
ByAppeared in BioNews 583
Women who have not conceived after two cycles of IVF may face reduced success rates if electing to undergo further cycles, according to a new study. The research is preliminary and many factors which may affect IVF success, such as the age and weight of the women, were not taken into account.
The study looked at 300,000 women across the United States receiving in total half a million IVF cycles over five years and found 48 percent of women had a baby after one or two cycles. However, after three cycles this number had only risen by five percent and after seven cycles stood at just 56 percent. This means that only three percent more women had successfully become pregnant after seven cycles of IVF than had done so after three.
'Don't quit if the first cycle isn't successful', said lead researcher Professor Barbara Luke from Michigan State University: '(But) if you haven't gotten pregnant by the third, the chances are slim to continue'.
In an attempt to successfully conceive, couples may incur great expense trying multiple cycles of IVF but there is currently little guidance as to the likelihood of success after the first. The findings indicated the best chance of conceiving is after the first IVF cycle, with 36 percent of women becoming pregnant at the first attempt. The success rate after the second cycle was significantly lower, with only an additional 12 percent of the total number of women in the study becoming pregnant on the second try. From the third cycle onwards the success rate dropped dramatically, with the total number of live births remaining largely unchanged.
The authors hope further investigation into factors that may affect fertility not addressed in the study may clarify success rates and aid both doctors and couples in their decision-making.
The research was presented at the American Society for Reproductive Medicine conference in Denver.