Effects of clomiphene treatment on infertile women with normal menstrual rhythm

Fourteen infertile women with normal menstrual rhythm were investigated; each provided daily blood samples throughout two menstrual cycles: one control cycle and another on therapy with clomiphene (50 mg/day) given either from days 1 to 5 (n = 7; group I) or from days 5 to 9 (n = 7; group II) of the cycle. The effects of this empirical clomiphene therapy on the menstrual cycles were assessed by reference to the delay from termination of clomiphene therapy to ovulation (day after the LH peak) and by comparing pre-ovulatory oestradiol levels and luteal phase progesterone indices (total progesterone levels from days 4 to 8 post LH peak) in patients' control and treated cycles. No differences were observed in the effects of the treatment on the two groups of women except that the clomiphene to ovulation delay was greater in those treated earlier in the cycle (group I). Clomiphene caused increased follicular development as indicated by elevated pre-ovulatory oestradiol levels but this was not followed by improved progesterone indices. Ovarian ultrasonography indicated that the increased follicular development was in terms of numbers of follicles and not in maturity or oestrogen biosynthetic capacity of individual follicles. The lack of increased luteal progesterone levels thereafter indicated that mean luteal progesterone production per luteinized follicle was reduced. Clomiphene therapy as given in this study was therefore not successful in stimulating increased follicular/luteal hormone production from the dominant follicle/corpus luteum in such patients.