Clomiphene citrate versus tamoxifen for ovulation induction in women with PCOS: a prospective randomized trial

ObjectiveTo reevaluate the efficacy of induction of ovulation with CC versus TMX in a group of anovulatory subfertile women with PCOS in a randomized controlled trial.Study designA prospective randomized controlled study in which 371 PCOS patients were randomly allocated into two treatment groups: group A (187 patients) where women received CC and group B (184 patients) where they received Tamoxifen for one treatment cycle. The outcome measures were number of growing and mature follicles, serum E2 (pg/ml), serum progesterone (ng/ml) and endometrial thickness, the occurrence of pregnancy and miscarriage.ResultsThe number of stimulated follicles reaching ≥16 mm diameter was significantly more in the CC group compared to Tamoxifen stimulated group (2.1 SD ± 0.1 vs. 1.1 SD ± 0.7, p < 0.0001). The endometrium at the time of hCG administration was significantly thicker in the TMX group (10.1 ± 0.1 mm vs. 9.3 ± 0.4 mm, p < 0.0001). Ovulation occurred in 120/187 cycles (64%) in the CC group and 95/184 cycles (51.6%) in the TMX group with a significant difference between two groups in favors of clomiphene (p = 0.01). Serum E2, on the day of hCG administration, was significantly higher in the clomiphene group (p < 0.0001). Pregnancy occurred in 35/187 cycles in group A (18.7%) and 20/184 cycles (10.8%) in group B and the difference was statistically significant (p = 0.04).ConclusionsClomiphene citrate is more successful than tamoxifen as a first line therapy for ovulation induction in women with PCOS.