Hormone patterns after induction of ovulation with clomiphene citrate: an age-related phenomenon

Since the introduction of clomiphene citrate (CC), more than three decades ago, a discrepancy has been observed between ovulation and pregnancy rates for which as yet no explanation exists. To investigate if ovulation disorde rs or abnormal hormonal patterns occur move often in CC-stimulated seemingl y ovulatory cycles, we performed hormonal and sonographic monitoring in fir st cycles of oligo- or amenorrheic patients who were stimulated with 50 mg CC, and compared the hormonal patterns to those in natural cycles of age-ma tched proven fertile women. Twenty-four first CC cycles were monitored. Twe lve cycles appeared to be ovulatory, eleven showed no follicle development and one cycle exhibited the luteinized unruptured follicle (LUF) phenomenon . Ten ovulatory cycles were compared with 27 unstimulated control cycles. I n four cycles stimulated by CC, a temporary decline in estradiol levels was apparent. In these cycles, estradiol reached a higher level on cycle day ( CD) 7 or 8 compared to cycles without a decline. Such an estradiol decline was seen in only one central cycle. Furthermore , estradiol level on CD 7 o r 8 appeared to be age-related. We conclude that the estradiol decline in CC-stimulated ovulatory cycles ma y be a consequence of a sharp rise after CC stimulation, and such a rise ma y be age-related and coincide with a diminished follicle quality. If this p henomenon is associated with a suboptimal cycle, and so contributes to the suboptimal pregnancy rater after ovulation-induction treatment with clomiph ene citrate, is still unknown.