Forbes published a story a few days ago about a study that tested results of couples who went through either three or six IUI cycles before moving on to IVF. I looked for the original article, which they said was published by Fertility and Sterility, but I wasn't able to find it in their list of articles.
According to the Forbes article, the couples were divided into two groups of 256 (3-cycle program) and 247 (6-cycle program). Couples from both groups who had not yet achieved pregnancy went on to up to six cycles of IVF.
The results were surprising - the average time to pregnancy in the 3-cycle group was eight months whereas it was eleven months in the 6-cycle group. In addition, the couples in the 3-cycle group saved on average over $2600. They explained part of this savings by the fact that more women from the 3-cycle group had singleton births (and births of multiples are more expensive). Overall, 67% of the couples in the 3-cycle group and 61% of the couples in the 6-cycle group ended the study with a baby.
I would be interested to hear why the researchers think that the success rate in the 3-cycle group was higher (if it is statistically significant) - does it have to do with being run down? Do the IUI cycles have a long-term negative effect on the uterine lining?