The effect of clomiphene and conjugated oestrogens on cervical mucus.

The analysis of 157 menstrual in 50 patients on ovulation-inducing regimens showed that in restoring ovulation clomiphene citrate inhibited cervical mucus production and caused hypersecretion of oestradiol. The inhibitory effect was inversely proportional to serum oestradiol levels, and the addition of conjugated oestrogens did not rectify the inhibitory effect, increase plasma oestradiol levels or increase cycle length. Doubling the clomiphene dosage made no significant difference to any of the parameters examined. The mechanism of this inhibitory effect is still obscure.