A comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on superovulation in Asian women with normal ovulatory cycles

Objective. To compare the effect of the aromatase inhibitor letrozole and clomiphene citrate (CC) on superovulation in women with normal ovulation.

Methods. A cross-over randomized study of 22 women with normal ovulation, divided randomly into two equal cohorts, was carried out. Each group of 11 women was randomly allocated to take letrozole or CC for one cycle. After washing out for one cycle, the alternative drug was administered in the subsequent cycle. The number and size of mature follicles, endometrial thickness, and estradiol and progesterone levels were monitored.

Results. The number of mature follicles and estradiol levels on ovulation day were significantly lower in the letrozole group than the CC group (p < 0.05 for both). However, no differences between the two groups in endometrial thickness and pattern were observed. Progesterone levels showed ovulation in all cycles.

Conclusions. The administration of 50 mg CC on days 3–5 was superior to 2.5 mg letrozole for superovulation induction in women with normal ovulation.     

A randomized comparison of ovulation induction and hormone profile between the aromatase inhibitor anastrozole and clomiphene citrate in women with infertility

Background. In the present study we evaluated and compared the effects of ovulation and hormonal dynamics induced by anastrozole and clomiphene citrate in women with infertility.

Materials and methods. Thirty-three infertile patients, aged 25–41 years, were enrolled. Patients received either anastrozole 1 mg daily (AI group) or clomiphene citrate 100 mg daily (CC group) from cycle day 3 to day 7. Number of mature follicles (≥18 mm), endometrial thickness, pregnancy rate and serial hormone profiles (follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E₂), testosterone and progesterone) were measured on cycle day 3, day 8, day 10, the day of intrauterine insemination (IUI), day 7 after IUI and day 14 after IUI.

Results. Baseline parameters were similar in the two groups, including age, body mass index, infertility duration and day-3 serum hormones except FSH. The mean FSH value on day 3 was significantly different (4.3 mIU/ml in the AI group vs. 6.3 mIU/ml in the CC group; p < 0.05). The women receiving anastrozole had fewer ovulatory follicles (1.2 in the AI group vs. 1.8 in the CC group; p < 0.05) and a thicker endometrium (10.6 mm in the AI group vs. 7.8 mm in the CC group; p < 0.05). The levels of progesterone and testosterone were similar during ovulation stimulation cycles in both groups. On the other hand, the AI group had a significantly higher LH level but a significantly lower E₂ level in the stimulation cycle.

Conclusion. Anastrozole has a high pregnancy rate, although it induces fewer ovulatory follicles compared with clomiphene citrate. The two drugs gave different responses of FSH, LH and E₂ during stimulation cycles.     

The effects of clomiphene citrate on normally ovulatory women

Objective: To investigate the efficacy of clomiphene citrate (CC) on normally ovulatory women who complained of infertility.

Design: A randomized study.

Setting: University Hospital.

Patient(s): Thirty-three normally ovulatory women with unexplained infertility.

Intervention(s): Eighteen women received CC at a 50-mg dosage. Fifteen women received no ovulation-induction drugs.

Main Outcome Measures: The pregnancy rate (PR) per patient, the PR per cycle, and the cumulative pregnancy rate.

Result(s): Seven patients in the CC group stopped taking CC, and observations were terminated because of antiestrogenic effects. The pregnancy rate (PR) per patient and the PR per cycle were significantly decreased (P < 0.005) in the CC group (4 of 18 [22.2%] and 4 of 66 [6.1%], respectively) than in the spontaneous group (11 of 15 [73.3%] and 11 of 52 [21.2%], respectively). Kaplan-Meier tests showed that the cumulative pregnancy rate in the CC group was significantly lower than in the spontaneous group (P <0.05). Five of seven patients who had stopped taking CC became pregnant in spontaneous cycles.

Conclusion(s): Administration of CC to normally ovulatory women is not efficacious in terms of increasing the pregnancy rate.     

A randomized trial of letrozole versus clomiphene citrate in women undergoing superovulation

OBJECTIVE: To compare the effects of the aromatase inhibitor letrozole (7.5 mg) and clomiphene citrate (CC; 100 mg) in women undergoing superovulation and IUI. DESIGN: Prospective randomized trial. SETTING: University teaching hospital. PATIENT(S): We studied a total of 238 cycles of superovulation and IUI in women with idiopathic infertility. INTERVENTIONS: Patients were randomized into treatment with 7.5 mg of letrozole daily (74 patients, 115 cycles) or 100 mg of CC daily (80 patients, 123 cycles). MAIN OUTCOME MEASURE(S): Number of follicles, endometrial thickness, pregnancy rate, and miscarriage rate. RESULT(S): The mean age, parity, and duration of infertility in both groups of patients were similar. There was no significant difference between the total number of developing follicles in the letrozole (5.7 +/- 3.7) and in the CC groups (4.8 +/- 2.5). The number of follicles of > or =14 mm and of >18 mm were 2.1 +/- 1.2 and 1.4 +/- 0.7 in the letrozole group, and 1.7 +/- 0.9 and 1.1 +/- 0.5 in the CC group, respectively. No difference was found in the endometrial thickness between the two groups (7.1 +/- 0.2 mm in the letrozole group, 8.2 +/- 5.9 mm in the CC group). The pregnancy rate per cycle was 11.5% in the letrozole group and 8.9% in the CC group. Four of the 11 pregnancies in the CC group resulted in a miscarriage (36.6%). CONCLUSION(S): Superovulation and IUI with letrozole and CC are associated with similar pregnancy rates, but the miscarriage rate is higher with CC. The ideal dose of letrozole remains unknown and further study is needed.     

Comparison of clomiphene citrate and letrozole for ovulation induction in women with polycystic ovary syndrome: a prospective randomized trial

To compare the therapeutic efficacy of clomiphene citrate (CC) and letrozole (LE) on ovulation, pregnancy, and live birth in women with polycystic ovary syndrome (PCOS); and to ensure if LE can replace CC as the first-line therapy for ovulation induction in these women. This is a prospectively, randomized, controlled trial in the tertiary hospital. Two-hundred and sixty-eight anovulatory PCOS patients were treated by CC or CC plus metformin and LE or LE plus metformin for three continuous cycles or conception; their ovulation rates, pregnancy rates, and live birth rates were calculated and compared. No significant difference was noted among the four groups regarding to the baseline data of clinical manifestations, serum sex hormone levels, and serum insulin levels. A total of 240 patients completed the therapies. The ovulation rate was significantly higher in the group LE than the group CC; however, no significant difference was noted between the groups LE and CC, CC, and CC?+?MET, or LE and LE?+?MET in the pregnancy rate, abortion rate, and live birth rate. No birth defect was found in the total of 63 newborns. CC regimen was still recommended to be the first-line therapy of ovulation induction for PCOS.     

人绝经期促性腺激素联合氯米芬或来曲唑用于多囊卵巢综合征患者促排卵疗效比较

的探讨人绝经期促性腺激素（HMG）＋氯米芬（CC）、HMG和来曲唑（LE）＋HMO对多囊卵巢综合征（PCOS）患者宫腔内供精人工授精的治疗效果。方法将2007年12月-2008年5月期间在我中心就诊的114例PCOS妇女的114个宫腔内人工授精（AID）周期分为3组：CC＋HMG周期组38个周期，HMG周期组38个周期，LE＋HMG周期组38个周期。分析比较3组的年龄、血清T水平、绒毛膜促性腺激素肌肉注射日（HCG日）平均卵泡直径（MFD）≥14mm的卵泡（成熟卵泡）个数、平均卵泡E2水平、子宫内膜厚度、HCG日单优势卵泡发育成熟百分率、HMG用量和周期妊娠率。结果CC＋HMG组、HMG组和LE＋HMG组患者年龄和血清T水平比较，差异无显著性（P〉0．05），CC＋HMG组HCG日成熟卵泡个数为（2．9±1．6）个，明显多于其他两组[HMG组为（1．6±1．0）个，LE＋HMG组为（1．9±1．2）个]，差异有显著性（P〈0．05），而内膜厚度较其他两组薄，差异有显著性（P〈0．05），HMG组与LE＋HMG组HCG日成熟卵泡个数和子宫内膜厚度比较，差异无显著性（P〉0．05）。3组HCG日单优势卵泡发育成熟百分率分别21．05％、78．95％和52．63％，差异有显著性（P〈0．05）。CC＋HMG组、HMG组和LE＋HMG组HMG用量分别为（4．89±1．59）支和（9．88±4．59）支、（9．68±4．67）支（75IU／支），CC＋HMG组与后两组比较，差异有显著性（P=0．00）。HMG组、LE＋HMG组HMG用量比较，差异无显著性（P〉0．05）。3组的周期妊娠率分别为36．84％、39．48％和31．57％，差异无显著性（P〉0．05）。结论HMG促排卵周期更易得到单优势卵泡发育成熟；CC＋HMG促排卵HMG用药量最少；CC＋HMG、HMG和LE＋HMG均可获得满意的周期妊娠率。     

Characteristics of baseline ovarian cysts in clomiphene citrate ovulation cycles

To evaluate the incidence and factors associated with ovarian cysts in infertile patients receiving clomiphene citrate (CC), we performed a retrospective cohort study involving 466 CC treatment cycles. Ovarian cysts are a common finding in patients presenting for CC, with approximately one in five patients having a baseline ovarian cyst >10 mm.     

Clomiphene citrate combined with metformin versus letrozole for induction of ovulation in clomiphene-resistant polycystic ovary syndrome: a randomized clinical trial

A total of 202 patients with clomiphene citrate (CC) -resistant polycystic ovary syndrome (PCOS) were randomly allocated into two arms of induction of ovulation; the first group (n?=?102) received CC 100?mg and metformin 500?mg while the second group (n?=?100) received letrozole 2.5?mg with ovulation rate, clinical pregnancy rate, adverse effects, and acceptability were assessed. Patients in the letrozole arm experienced higher rate of ovulation (82% versus 43.1%, p?p?p?p?p?p?p?相似文献   

A comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on superovulation in Asian women with normal ovulatory cycles

OBJECTIVE: To compare the effect of the aromatase inhibitor letrozole and clomiphene citrate (CC) on superovulation in women with normal ovulation. METHODS: A cross-over randomized study of 22 women with normal ovulation, divided randomly into two equal cohorts, was carried out. Each group of 11 women was randomly allocated to take letrozole or CC for one cycle. After washing out for one cycle, the alternative drug was administered in the subsequent cycle. The number and size of mature follicles, endometrial thickness, and estradiol and progesterone levels were monitored. RESULTS: The number of mature follicles and estradiol levels on ovulation day were significantly lower in the letrozole group than the CC group (p < 0.05 for both). However, no differences between the two groups in endometrial thickness and pattern were observed. Progesterone levels showed ovulation in all cycles. CONCLUSIONS: The administration of 50 mg CC on days 3-5 was superior to 2.5 mg letrozole for superovulation induction in women with normal ovulation.     

Systematic review of the treatment of ovulatory infertility with clomiphene citrate and intrauterine insemination

BACKGROUND: Controlled ovarian hyperstimulation (COH) with clomiphene citrate (CC) combined with intrauterine insemination (IUI) is often used as treatment for ovulatory infertility which includes unexplained, male, cervical, endometriosis, and tubal infertility. AIMS: To review the effectiveness of CC and IUI in ovulatory infertility. METHODS: Systematic review of pertinent randomised controlled trials (RCT) using the bibliographic databases MEDLINE and EMBASE. References of selected articles identified were hand-searched for additional relevant citations. RESULTS: Six published RCT were included in the overall review. Meta-analysis demonstrated a higher cycle pregnancy rate (CPR) with CC and IUI compared to timed intercourse in the natural cycle (P < 0.001 and odds ratio = 4.6, 95% CI = 1.9-11.3). Treatment with gonadotrophins and IUI results in a higher CPR compared to CC and IUI (P = 0.005 and odds ratio = 2.9, 95% CI = 1.3-6.2). Further RCT are required comparing CC and IUI with IUI or CC alone before one can make firm conclusions. CONCLUSIONS: Clomiphene citrate combined with IUI is more effective than timed intercourse in the natural cycle at achieving pregnancy in couples with ovulatory infertility. However, treatment with gonadotrophins and IUI is superior to CC and IUI.     

Comparison of endometrial receptivity of clomiphene citrate versus letrozole in women with polycystic ovary syndrome: a randomized controlled study

Abstract

The aim of the study was to compare the effect of clomiphene citrate (CC) and letrozole on endometrial receptivity for ovulation induction in women with polycystic ovary syndrome (PCOS). A randomized controlled study included 160 patients diagnosed with PCOS, out of which 80 patients received 50?mg of CC and 80 patients received 2.5?mg of letrozole for successful ovulation induction. Endometrial thickness and pattern, the blood flow of uterine artery and subendometrial region, endometrial volume and vascularization index were measured. The ratio of multilayered endometrial pattern in letrozole group was significantly increased on the day of human chorionic gonadotropin (hCG) administration compared with CC group (77.5% vs. 55.0%). The volume, vascularization index (VI), flow index (FI), and vascularization flow index (VFI) of endometrium on the day of hCG administration and 7–9?days after ovulation in letrozole group were significantly increased. The biochemical pregnancy rate, clinical pregnancy rate, and ongoing pregnancy rate in letrozole group were significantly increased compared with CC group (36.3%, 30.0%, 22.5% vs. 21.3%, 13.8%, 10.0%, respectively). Letrozole increased pregnancy rates by improving endometrial receptivity compared with CC in patients with PCOS.