The mean interval to conception: a measure of utility for the analysis of decisions involving fertility.

This article describes a method of assigning a utility, or relative worth, to outcomes based on the mean interval to conception (MIC). In the formula MIC = 1/fC, the subscript C is the proportion of a given cohort of women who would conceive if given an infinitely long trial and fC is the fecundability or monthly probability of conception among this subgroup. MIC and MIO (interval of observation for those who do not conceive) are used as the utilities in decision analyses of fertility treatment. This method provides a semiquantitative estimate that reflects uncertainty of cure of infertility and variation in amount of time spent in the nonpregnant state after infertility treatment.