OBJECTIVE
To compare the effect of clomiphene citrate (CC) and letrozole on endometrial receptivity in women with polycystic ovary syndrome (PCOS).
METHODS
A randomized controlled trial.
METHODS
University teaching hospital.
METHODS
Ten anovulatory women with PCOS and 5 fertile ovulatory women.
METHODS
Patients received 2.5 mg of letrozole on cycle days 3-7 (5 patients, 1 cycle) or 50 mg of CC on cycle days 5-9 (5 patients, 1 cycle).
METHODS
Serum estrogen (E) and progesterone (P) endometrial protein and messenger RNA (mRNA) expression of leukemia inhibitory <em>factor</em> (LIF), dickkhopf homolog 1 (DKK-1), <em>fibroblast</em> <em>growth</em> <em>factor</em> <em>22</em> (FGF-<em>22</em>), and endometrial mRNA expression of LIF/GP130 receptor (LIFR).
RESULTS
No statistically significant differences were observed between groups compared with fertile ovulatory women when serum E and P were examined, or between body mass index (BMI), and cycle day at time of biopsy. Letrozole increased mRNA expression of LIF, DKK1, LIFR, and FGF-<em>22</em>, whereas CC only increased endometrial mRNA expression of LIF. Letrozole mRNA expression directly translated into increased protein expression of like genes in the endometrium. The CC protein expression of DKK-1 was significantly decreased compared with controls.
CONCLUSIONS
Letrozole positively influences a number of markers of endometrial receptivity compared with CC.