Effect of Aromatase Inhibitor (AI) in Polycystic Ovary Syndrome Patients with an Inadequate Response to Clomiphene Citrate

Kim, Hye Ok; Yang, Kwang Moon; Hur, Kuol; Park, Chan Woo; Cha, Sun Hwa; Kim, Hae Suk; Kim, Jin Yeong; Song, In Ok; Koong, Mi Kyung

Abstract

OBJECTIVE
To evaluate the effectiveness of aromatase inhibitor (AI) for ovulation induction in polycystic ovary syndrome (PCOS) patients with thin endometrium, hyper-responsiveness after clomiphene citrate (CC) treatment. MATERIAL AND METHODS: A prospective study was performed in 43 PCOS patients (50 cycles) with ovulatory dysfunction between March 2004 and September 2004. AI group (total 36 cycles) included the patients 1) with thin endometrium below 6 mm on hCG day after CC (n=17), 2) with more than 5 ovulatory follicles after 50mg of CC (n=4), 3) who do not want multiple pregnancy (n=14). Patients were treated with Letrozole 2.5mg for days 3 to 7 of the menstrual cycle. CC group (total 14 cycles) were treated with CC 50~100 mg.
RESULTS
In PCOS patients, ovulation was occurred 97.2% after AI use. Between AI group and CC group, there was no significant difference in the mean age, duration of infertility, interval of menstruation, basal FSH, prior treatment cycles, and the day of hCG administration. But, the number of mature follicles (> or =15 mm) was lower in the AI group (1.08+/-0.45 vs. 1.64+/-0.75) (p=0.018), and the thickness of endometrium (mm) was significantly thicker in the AI group (10.35+/-1.74 vs. 9.23+/-1.61) (p=0.044), and E2 (pg/ml) concentration on hCG day was lower in the AI group (116.9+/-75.8 vs. 479.5+/-300.8) (p=0.001). Among the AI group, patients with prior thin endometrium (below 6 mm) during CC treatment showed 10.6+/-1.6 mm in the endometrial thickness and 106.6+/-66.8 pg/ml in E2 concentration. Patients with more than 5 ovulatory follicles after CC showed decreased follicle number (1.25+/-0.5) compared to prior CC cycle.
CONCLUSIONS
In PCOS patients, AI group showed significantly thicker endometrium, lesser number of mature follicles, and lower E2 concentration on hCG day than CC group. AI might be useful alternative treatment for ovulation induction in PCOS patients with thin endometrium and hyper-responsiveness after CC treatment.