Observations on the combination of clomiphene citrate-human menopausal gonadotropin-human chorionic gonadotropin in the management of anovulation

A new era in ovulation induction

OBJECTIVE

To evaluate the efficacy of aromatase inhibitors in ovulation induction, superovulation, and IVF.

DESIGN

A literature search was conducted with the key words "aromatase inhibitor," "letrozole," "anastrazole," "ovulation induction," "ovulation," and "superovulation" in MEDLINE, EMBASE, and the Cochrane Database of systematic reviews.

RESULT(S)

Ovulation induction with letrozole is associated with an ovulation rate of 70%-84% and a pregnancy rate of 20%-27% per cycle. In one study, ovulation and pregnancy rates with letrozole seemed to be higher than those of anastrazole. In superovulation, letrozole is associated with few developing follicles and thick endometrium. The use of letrozole for superovulation is associated with a pregnancy rate higher than with the use of clomiphene citrate (CC) (16.7% vs. 5.6%). The addition of letrozole to FSH treatment leads to a decreased FSH requirement. The pregnancy rate for treatment with letrozole and FSH was similar to that for FSH alone.

CONCLUSION(S)

Aromatase inhibitors are as effective as or superior to CC in ovulation induction and in superovulation. Unlike CC, they do not carry an antiestrogenic effect on the endometrium. Given the advantages of aromatase inhibitors, they can be used to replace CC as ovulation-inducing drugs. Their role in IVF remains to be determined.

Effects of letrozole on superovulation with gonadotropins in women undergoing intrauterine insemination

OBJECTIVE

To investigate the effects of letrozole in patients undergoing superovulation with gonadotropins and IUI.

DESIGN

Retrospective analysis.

SETTING

Academic teaching hospital.

PATIENT(S)

Women younger than 40 years of age with patent fallopian tubes and infertility of more than 1 year in duration who were undergoing IUI and gonadotropin therapy.

INTERVENTION(S)

Gonadotropins alone administered from day 3 or a combination of letrozole, 5 mg/d on day 3 to 7, and gonadotropins starting on day 5 of the menstrual cycle. Ultrasonography was performed before initiation of treatment, on day 9 of menstrual cycle, and as required thereafter until the dominant follicle reached 18 mm in diameter. Ovulation was triggered with 10,000 IU of hCG, and IUI was performed 24 and 48 hours later.

MAIN OUTCOME MEASURE(S)

Gonadotropin requirements, endometrial thickness, number of follicles, and pregnancy rate.

RESULT(S)

All 205 IUI treatment cycles conducted from March 2001 to March 2002 were included. Gonadotropins alone were used in 145 cycles and combination therapy was used in 60 cycles. Patients cotreated with letrozole required fewer gonadotropin administrations (median difference, 300 IU [95% confidence interval (CI), 225-375 IU]), developed more follicles larger than 14 mm (median difference, 1 follicle [95% CI, 1-2 follicles), and had a thinner endometrium (median difference, 1 mm [95% CI, 0.4-1.6 mm]). The pregnancy rate did not differ between patients using gonadotropin alone and those using gonadotropin plus letrozole (20.9% vs. 21.6%).

CONCLUSION(S)

The addition of letrozole to gonadotropins decreases gonadotropin requirements, increases the number of pre-ovulatory follicles and decreases endometrial thickness, without a negative effect on pregnancy rates.

Minimal stimulation protocol for use with intrauterine insemination in the treatment of infertility

OBJECTIVE

To determine whether minimal stimulation with clomiphene and one injection of 150 IU of human menopausal gonadotrophin (hMG) provides pregnancy rates comparable with those in a conventional full hMG stimulation protocol for infertile patients undergoing intrauterine insemination (IUI).

METHODS

A prospective study was carried out at the Infertility Clinic of a teaching institute and tertiary care referral center in Chandigarh, India. Two hundred couples with either unexplained infertility or ovulatory dysfunction cases who ovulated with clomiphene citrate (CC) but failed to conceive were offered ovarian stimulation with CC and hMG along with IUI for 420 cycles. Pregnancy rate, medication and monitoring cost were compared between minimal and conventional stimulation protocols.

RESULTS

There was no difference in the couples of the two stimulation protocols regarding their age, duration and type of infertility as well as cause of infertility. Number of ampoules of hMG and monitoring costs were significantly higher in the full hMG stimulation cases whereas pregnancy rate was comparable in both protocols.

CONCLUSION

Minimal stimulation appears to be an effective protocol in cases of unexplained infertility undergoing intrauterine insemination. Reduced cost and minimal monitoring is appealing to patients and the clinician.

Pregnancy rates using CC/hMG or hMG alone

OBJECTIVE

The purpose of our study was to determine which of the two drug regimens is more successful in achieving conception in the infertile couple.

SUBJECTS

One hundred and sixty women with primary infertility were included in this study. Group A, consisted of 102 patients were treated with clomiphene citrate (CC) and human menopausal gonadotrophin (hMG). Group B, consisted of 58 patients were treated with hMG alone.

METHODS

This retrospective study was performed between April 1993 and March 1996, to compare the pregnancy rates in women using two drug regimens with ultrasound scan and serum E2 to monitor ovulation induction.

RESULTS

The pregnancy rate per patient in Group A was significantly higher than in Group B (46% vs 25.9%) as was the pregnancy rate per treatment cycle (31.3% vs 15.8%) pregnancy loss was lower in Group A than in Group B (17% vs 33.3%). The incidence of multiple pregnancy was 8.5% in Group A, and 13.3% in Group B. While the incidence of ovarian hyperstimulation syndrome was 3% in Group A, and 6.9% in Group B.

CONCLUSIONS

We concluded that the use of CC + hMG in an assisted conception programme gives a better pregnancy rate 46% than in the hMG alone 25.9%. These data with the use of U/S scan and serum E2 clearly showed that the use of CC + hMG is a successful and safe method for the treatment of infertile patients.

Minimal stimulation achieves pregnancy rates comparable to human menopausal gonadotropins in the treatment of infertility

OBJECTIVE

To examine the effectiveness of a novel clomiphene citrate (CC) and hMG combination protocol ("minimal stimulation") for controlled ovarian hyperstimulation. Minimal stimulation consists of administering 100 mg/d CC for 5 days followed by a single dose of 150 IU hMG. The results of this analysis are compared with those of an hMG-alone protocol. In vitro fertilization-embryo transfer and donor insemination patients are excluded from this analysis.

DESIGN

Retrospective review of minimal stimulation and hMG cycles from January 1, 1989 to December 31, 1992.

SETTING

Tertiary care center reproductive endocrinology and infertility clinic.

PATIENTS

Two hundred thirty-two women who underwent 549 treatment cycles.

MAIN OUTCOME MEASURES

Clinical and multiple pregnancy rates (PRs) and medication costs.

RESULTS

Sixty-one women received 106 cycles of minimal stimulation and 183 received 443 cycles of hMG. Although subject groups were not assigned randomly, multivariate analysis detected no significant differences between the treatment groups. The total ampules of hMG required differed significantly (2.0 for minimal stimulation versus 16.8 +/- 8.5 [mean +/- SD] for hMG). Pregnancy rates and multiple gestation rates were similar. Medication expense of minimal stimulation is 21% that of the hMG protocol.

CONCLUSIONS

Minimal stimulation is as effective as hMG in the population examined. The comparable PRs and decreased medication costs of minimal stimulation justifies further evaluation of its role in the treatment of infertility.

Ultrasonographic and clinical correlates of menotropin versus sequential clomiphene citrate: menotropin therapy for induction of ovulation

Forty-six women remaining infertile with clomiphene citrate (CC) with or without human chorionic gonadotropin (hCG) were treated by either human menopausal gonadotropin (hMG, 44 cycles) or CC + hMG (33 cycles) and monitored by serum estradiol (E2) and ultrasonography. Ovarian hyperstimulation syndrome (OHS) and pregnancy outcome were compared in both regimens. In the presence of dominant follicles (greater than or equal to 18 mm) alone or with a single secondary follicle (14 to 16 mm) at hCG administration, OHS did not develop. A significant increase in OHS was noted when three or more secondary follicles were observed. Overall pregnancy rates were similar in both regimens but significantly higher when hCG was injected before rather than after the E2 peak. The results suggest secondary follicles rather than dominant follicles are a valuable sign of possible OHS development; and CC + hMG should be considered in CC-failure patients.

Progressive dosages of clomiphene in hypothalamic anovulation

A group of 89 sterile patients with hypothalamic anovulation were subjected to progressive dosages of clomiphene citrate according to a predesigned program. In order to analyze our results, we divided our patients into seven groups, according to the largest dosage of clomiphene citrate received. Clinical features were revised in relation to the ovulatory dose of clomiphene. Significant differences between groups regarding weight, menstrual pattern, age at menarche, and hirsutism were not found. Obesity increased the dose required for ovulation when it was less than 900 mg/cycle, but had no effect at higher doses. The ovulation rate, pregnancies, prenatal wastage, and side effects of treatment were analyzed; and it was found that the scheme for ovulation induction used, without expensive and sophisticated ovarian monitoring resources, improved ovulation and pregnancy rates with few and unimportant deleterious side effects.

Sequential clomiphene citrate-menotropin therapy for induction or enhancement of ovulation

Either to induce ovulation in anovulatory infertility patients or to enhance ovulation in patients with mild endometriosis or luteal phase inadequacy, we utilized a sequential regimen of low-dose clomiphene citrate (CC) followed by human menopausal gonadotropin (hMG) injections on alternate days; duration and dosage of menotropin therapy was individualized by using serum estradiol levels for monitoring until the time of administration of human chorionic gonadotropins. Previous therapeutic efforts without menotropins had been unsuccessful in all patients. One third of 70 treated patients conceived during 156 treatment cycles. The pregnancy rate was 44% in anovulatory patients (n = 34), and 26% in patients with ovulation dysfunction (n = 23). Pregnancy rates declined with patient's age. Four of the 23 patients that conceived had a spontaneous abortion (17%). The multiple gestation rate was 10.5%. A relative inhibition of cervical mucus development was noted and shown to be caused by CC. Hyperstimulation occurred in three patients. The discussed CC-hMG regimen approaches the effectiveness of standard hMG therapy; but compared with standard hMG therapy, it has significant economic advantages and seems to have a markedly lower rate of multiple gestation. However, like standard hMG therapy, CC-hMG therapy requires careful monitoring specifically, because hyperstimulation may occur.