Clomiphene citrate challenge test: cycle to cycle variability of cycle day 10 follicle stimulating hormone level

The clomiphene citrate challenge test (CCCT), a means of assessing ovarian reserve, was shown by several studies to have an excellent predictive value for achieving conception in natural cycles, during ovulation induction and in-vitro fertilization cycles. Accordingly we elected to study the cycle to cycle variability of CCCT so as to determine the reliability of a single CCCT result. Two groups of patients were studied, the first (n = 40) were those patients who were performing the test because it was indicated, and the second (n = 24) were those who were receiving clomiphene citrate for ovulation induction. In both groups CCCT intercycle variability was significant in 75% of the cases, but this variability altered the prognostic values of the test in only 40% of the first group. In conclusion, our study showed a high percentage of intercycle variability of CCCT but further studies are needed to evaluate the influence of this variability on potential conception.