Use of letrozole versus clomiphene citrate combined with gonadotropins in intrauterine insemination cycles: a pilot study.
OBJECTIVE
To compare the clinical outcomes between letrozole and clomiphene citrate (CC) in gonadotropin-combined intrauterine insemination (IUI) cycles.


METHODS
Prospective pilot study.


METHODS
One university hospital and two private infertility clinics.


METHODS
Ninety-three infertile couples eligible for superovulation and IUI.


METHODS
A letrozole dose of 2.5 mg/day (n = 66) or a CC dose of 100 mg/day (n = 27) was given on day 3-7 of the menstrual cycle, combined with human menopausal gonadotropin (hMG) at a dose 150 IU every other day starting on day 5.


METHODS
The number of mature follicles, serum estradiol (E2) and progesterone (P) levels, endometrial thicknesses on the day of human chorionic gonadotropin (hCG), and clinical pregnancy rates.


RESULTS
The patients' clinical characteristics were comparable between the two groups. The number of mature follicles (3.2 +/- 1.7 vs. 5.6 +/- 2.4) and serum E2 levels on the day of hCG (231.0 +/- 179.8 vs. 1,371.7 +/- 750.5 pg/mL) were significantly lower in the letrozole group. No significant differences were found in endometrial thickness measured on the day of hCG or clinical pregnancy rates (18.2% vs. 25.9%). The rate of patients with serum P levels > 1.0 ng/mL on the day of hCG was significantly lower in the letrozole group (4.5% vs. 25.9%).


CONCLUSIONS
Letrozole produced a comparable pregnancy rate vs. CC in gonadotropin-combined IUI cycles. Our results should be confirmed in larger populations with proper randomization.
Jee
Byung Chul
BC
Department of Obstetrics and Gynecology, Seoul National University Bundang Hospital, Seongnam, Korea.
Ku
Seung Yup
SY
Suh
Chang Suk
CS
Kim
Ki Chul
KC
Lee
Won Don
WD
Kim
Seok Hyun
SH