RETRACTED ARTICLE: Clomiphene citrate or aromatase inhibitors combined with gonadotropins for superovulation in women undergoing intrauterine insemination: A prospective randomised trial

Abstract

The objective of this study was to test the use of letrozole in combination with follicle-stimulating hormone (FSH) vs clomiphene citrate (CC) with FSH for ovarian hyperstimulation prior to intrauterine insemination (IUI). A prospective randomised trial in which 280 women with unexplained infertility were randomised to 100 mg of CC (141 patients, 219 cycles) or 5 mg of letrozole daily (139 patients, 215 cycles) for 5 days starting on day 3 of menses both combined with gonadotropins for ovarian stimulation prior to IUI. The primary outcome measures were the number of growing and mature follicles, the concentrations of serum E2 (pg/ml) and progesterone (ng/ml), and the endometrial thickness (mm). The secondary outcome measure was the occurrence of pregnancy and miscarriage. The total number of follicles was significantly greater in the CC group (4.1 +/- 0.46 vs 2.6 +/- 0.43). There was no significant difference in endometrial thickness between the two groups. Pregnancy occurred in 33 out of 139 patients (215 cycles) in the letrozole group (23.7% and 15.3%, respectively) and 37 out of 141 patients (219 cycles) (26.2% and 16.8%, respectively) in the CC group; the differences were not statistically significant. The allied use of either CC or letrozole, during ovarian stimulation to reduce the dose of gonadotropins prior to IUI is justified. This approach will reduce the cost of stimulation protocols without effect on the treatment outcome and letrozole has no advantage over CC in this respect.

Preliminary study of letrozole use for improving spermatogenesis in non-obstructive azoospermia patients with normal serum FSH

“…4,12,13 Additional studies have also shown that letrozole does not increase the risk for congenital malformations with ovulation induction. 14 If our data are confirmed, this and future research may save some NOA patients from surgery. Future research in this field should also consider the possibility that letrozole administration could improve sperm yield in TESE/FNA and/or sperm retrieval for intracytoplasmic sperm injection.…”

Dual Ovulation Triggering With Follicle-Stimulating Hormone and Human Chorionic Gonadotropin in Women With Unexplained Infertility Underwent Letrozole Superovulation and Intrauterine Insemination: A Randomized Controlled Trial.

“…The current study reported a clinical pregnancy rate of 25% and a live birth rate of 21.3% for the total letrozolestimulated cycles, regardless of the ovulation triggering protocol; the rates that accord with those formerly stated in various studies evaluated letrozole superovulation in women with UI (table 4) [11][12][13][14][15][16] . However, dual triggering by FSH/hCG compared to hCG alone improved the outcome of Letrozole-stimulated IUI cycles manifested as significantly higher pregnancy rate pre-cycle (12.5% vs. 5.8%: p=0.049) and per-woman (33.33% vs. 16.67%: p=0.049), and a significantly higher live birth rate (29.6% vs, 12.5%; p= 0.039).…”

“…However, dual triggering by FSH/hCG compared to hCG alone improved the outcome of Letrozole-stimulated IUI cycles manifested as significantly higher pregnancy rate pre-cycle (12.5% vs. 5.8%: p=0.049) and per-woman (33.33% vs. 16.67%: p=0.049), and a significantly higher live birth rate (29.6% vs, 12.5%; p= 0.039). The reported pregnancy and live birth rates in the FSH/hCG trigger group are superior to those reported in diverse studies evaluating different letrozole-stimulated IUI protocols in women with UI (table 4) [11][12][13][14][15][16] . To our knowledge, this is the first trial planned to appraise the effect of FSH/hCG dual triggering in letrozole-stimulated cycles in ladies with UI.…”

Severe ovarian hyperstimulation syndrome after letrozole-gonadotropin stimulation: a case report

“…However, in cycles involving adjunctive treatment with letrozole, serum E 2 concentrations have limited utility. Studies in infertile anovulatory women have demonstrated that letrozole can induce ovulation and is associated with lower peak E 2 levels than with other methods of ovulation induction [6,7]. Because E 2 levels rise only modestly during treatment with gonadotropins and letrozole, it might be assumed that risk for developing OHSS is low.…”