Hormonal profiles following clomiphene citrate therapy in conception and nonconception cycles

The hormonal profiles following clomiphene citrate (CC) administration during a single cycle were compared in infertile women who conceived and in those who did not. Of 41 treated patients, ovulation was assumed to have occurred in 28 and was confirmed by clinical pregnancy in five. In the 28 women who presumably ovulated, two distinct patterns of hormonal secretion were observed. A normal response was exhibited by 17 patients (including the five who became pregnant). The other 11 patients exhibited an abnormal response, characterized by significantly higher luteinizing hormone (LH)/follicle-stimulating hormone (FSH) ratios than in the normal response group from day 9 until the occurrence of the LH peak (days 9 and 10, P less than 0.05; days 11 and 12, P less than 0.001), and significantly higher oestradiol (E2) levels throughout the cycle (P less than 0.01). In addition, in comparison with the normal response group their LH levels during the follicular phase were significantly higher (P less than 0.05) but their LH peaks at ovulation were significantly lower (P less than 0.02). Moreover, their progesterone levels, in contrast to those in the normal response group, began to increase prior to the LH peak and remained high during the early and mid-luteal phases. None of the women who exhibited this abnormal gonadotrophin response to CC therapy achieved a clinical pregnancy. Exposure to high LH levels in the follicular phase following CC therapy seems to reduce the rate of fertilization and/or to contribute to early embryonic loss.