Use of an aromatase inhibitor for induction of ovulation in patients with an inadequate response to clomiphene citrate

Relative potencies of anastrozole and letrozole to suppress estradiol in breast cancer patients undergoing ovarian stimulation before in vitro fertilization

CONTEXT

Breast cancer patients undergoing controlled ovarian hyperstimulation (COH) for embryo or oocyte cryopreservation should be induced by the method that leads to the least increase in estradiol (E(2)) levels.

OBJECTIVE

The aim of the study was to determine the potency of anastrozole to suppress serum E(2) levels in breast cancer patients undergoing COH.

DESIGN AND SETTING

A prospective sequential cohort study was conducted in an academic center for reproductive medicine between May 2003 and November 2005 for letrozole and between December 2005 and April 2006 for anastrozole.

PATIENTS

Breast cancer patients presenting for fertility preservation participated in the study.

INTERVENTION

COH using FSH and letrozole (n = 47) or anastrozole (n = 7) was followed by oocyte retrieval and embryo cryopreservation.

MAIN OUTCOME MEASURES

Serum E(2) levels, area under the curve for E(2), and outcomes of COH cycles were measured.

RESULTS

There were no significant differences between the two groups regarding length of stimulation, total gonadotropin dose, number of follicles larger than 17 mm, and the lead follicle size on human chorionic gonadotropin (hCG) day and number of embryos cryopreserved. The mean E(2) levels on the day of hCG and post-hCG days were higher in the anastrozole group compared to the letrozole group (1325.89 +/- 833.17 and 2515.07 +/- 1368.52 vs. 427.78 +/- 278.24 and 714.38 +/- 440.83 pg.d/ml; P < or = 0.01), respectively, even when anastrozole dose was increased up to 10 mg/d. The mean area under the curve was significantly higher in the anastrozole group compared to the letrozole group (4402.93 +/- 1526.7 vs. 1287.48 +/- 732.17 pg.d/ml; P <0.004).

CONCLUSIONS

Breast cancer patients who underwent ovarian stimulation with anastrozole had a significantly higher exposure to E(2) than those who were stimulated with letrozole.

Management of poor responders: can outcomes be improved with a novel gonadotropin-releasing hormone antagonist/letrozole protocol?

OBJECTIVE

To compare the efficacy of a microdose GnRH agonist flare (ML) with a GnRH antagonist/letrozole (AL) protocol before IVF-ET in poor responders.

DESIGN

Prospective controlled trial.

SETTING

Private assisted reproductive technology center.

PATIENT(S)

Five hundred thirty-four infertile women classified as past or potential poor responders based on clinic-specific criteria.

INTERVENTION(S)

Poor responders were prospectively assigned to an ML or AL protocol in a 2:1 ratio, respectively.

MAIN OUTCOME MEASURE(S)

Results of controlled ovarian hyperstimulation and implantation and ongoing pregnancy rates.

RESULT(S)

Patient characteristics were similar between the two protocol groups. There were no significant differences in mean age, number of oocytes, fertilization rates, number of embryos transferred, or embryo score. Peak E(2) levels were significantly lower in the AL group. Ongoing pregnancy rates were significantly higher in the ML group (52% vs. 37%). Trends toward increased implantation and lower cancellation rates were also noted, but these did not reach statistical significance.

CONCLUSION(S)

Quantitative results of stimulation between the ML and AL protocols were equivalent with the exception of peak E(2) levels. However, the higher ongoing pregnancy rates and trend toward superior implantation rates would suggest that ML represents a preferred approach for the poor responder. An increased sample size would be necessary to verify these findings.

Randomized controlled trial of three doses of letrozole for ovulation induction in patients with unexplained infertility

The aromatase inhibitor letrozole is a novel agent that can be used as an alternative to clomiphene citrate for ovulation induction in patients with unexplained infertility. The dose of letrozole used has varied between studies, and this study aimed to compare the three most commonly used doses: 2.5, 5 and 7.5 mg. A total of 179 patients were randomly recruited in this prospective study with 58, 61 and 60 patients in each dosage group respectively. This study reports a significantly higher (P < 0.05) number of follicles (total, > 14 mm and > or = 18 mm) on the day of administration of human chorionic gonadotrophin in the 7.5 mg group, associated with significantly fewer (P < 0.05) days of stimulation. However the pregnancy and miscarriage rates were similar in the three groups. In conclusion, it seems that the use of higher doses of letrozole offers no advantage in terms of pregnancy rates over the lower (2.5 mg) dose.

Pregnancy considerations in women with polycystic ovary syndrome

Women with polycystic ovary syndrome (PCOS) are subfecund, and while anovulatory infertility is most likely the primary cause, other factors may contribute. Recent data suggest that women with PCOS are at increased risk for preterm labor, preeclampsia, and gestational diabetes, though the evidence for increased miscarriage rates is less certain. There is no evidence-based schema for achieving pregnancy in women with PCOS, though lifestyle modification, clomiphene citrate, and metformin are the current front line therapies. There are few data to support treatment during pregnancy with metformin in women with PCOS to prevent pregnancy loss or pregnancy complications.

Letrozole for ovulation induction and fertility preservation by embryo cryopreservation in young women with endometrial carcinoma

OBJECTIVE

To reduce estrogen exposure in women with endometrial cancer undergoing in vitro fertilization using an aromatase inhibitor.

DESIGN

Prospective case series.

SETTING

Academic center for reproductive medicine.

PATIENT(S)

Endometrial carcinoma patients presenting for fertility preservation or fresh embryo transfer to gestational carrier.

INTERVENTION(S)

Four patients with endometroid carcinoma underwent five IVF cycles for immediate or delayed embryo transfer to gestational carriers before or after staging and definitive surgery. To prevent surge in E(2) levels, letrozole was started 2 days before gonadotropin administration and then given concomitantly. Embryos were either cryopreserved for fertility preservation or transferred freshly to a surrogate.

MAIN OUTCOME MEASURE(S)

Peak E(2) level during stimulation, pregnancy in a gestational carrier.

RESULT(S)

Peak E(2) level during stimulation was 386.67 +/- 102.93 pg/mL. A mean of 7 +/- 2.85 oocytes were retrieved, resulting in 4.8 +/- 1.76 embryos per cycle. In one patient, two embryos were transferred to a surrogate, resulting in a triplet pregnancy. The delivery occurred at 31 weeks and the infants did not show any congenital or developmental abnormalities. Three patients had their embryos cryopreserved for future use.

CONCLUSION(S)

The use of letrozole and gonadotropins is associated with lower E(2) levels compared with standard stimulation cycles in endometrial carcinoma patients. Combination of this approach with surrogacy may enable these young women to preserve their fertility.

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 (> or =18 mm), endometrial thickness, pregnancy rate and serial hormone profiles (follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E(2)), 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 E(2) 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.

Report of four donor-recipient oocyte cryopreservation cycles resulting in high pregnancy and implantation rates

OBJECTIVE

To determine the clinical potential of donor-oocyte cryopreservation and thaw techniques for recipient patients.

DESIGN

Institutional review board-approved prospective study of donor oocyte cryopreservation.

SETTING

A large, private infertility center.

PATIENT(S)

Four anonymous oocyte donors underwent ovarian hyperstimulation for the purpose of oocyte retrieval and cryopreservation. The oocytes were subsequently thawed, fertilized, and transferred to 4 recipient patients.

INTERVENTION(S)

Oocytes were obtained from young donor patients and were cryopreserved with a slow freeze/rapid thaw protocol in which 1,2-propanediol (PrOH) and sucrose were used as cryoprotectants. Oocytes that survived were inseminated using intracytoplasmic sperm injection (ICSI). Resulting embryos were replaced into the recipient patients on the third day post-insemination.

MAIN OUTCOME MEASURE(S)

Post-thaw survival rate, fertilization rate, cleavage rate, implantation and clinical pregnancy rates.

RESULT(S)

A total of 79 metaphase II oocytes were frozen, stored frozen overnight in liquid nitrogen, and then thawed. The post-thaw survival rate was 86.1%. Normal fertilization following ICSI occurred in 89.7% of the surviving oocytes. Cleavage was observed in 91.8% of normally fertilized oocytes. A total of 23 embryos were transferred to 4 recipient patients. A clinical pregnancy rate of 75% and an implantation rate of 26.1% were achieved.

CONCLUSION(S)

Human oocyte cryopreservation is an effective technique that can be applied in clinical situations with high oocyte survival and clinical pregnancy rates expected.

Aromatase inhibitors in ovarian stimulation for IVF/ICSI: a pilot study

This prospective randomized pilot study was aimed at investigating the effect of the novel addition of aromatase inhibitors to an ovarian stimulation protocol for IVF or intracytoplasmic sperm injection, on endocrine parameters including serum androgen, oestrogen, progesterone, LH and FSH concentrations. The patients were randomized to receiving letrozole (group A; n = 10), versus no letrozole (group B; n = 10) in an ovarian stimulation protocol with recombinant FSH 150 IU/day starting on day 2 of the cycle, and gonadotrophin-releasing hormone antagonist 0.25 mg/day starting on day 6 of the cycle. Median LH concentrations were significantly higher (P < 0.01) in group A versus group B during letrozole administration. Median serum oestradiol concentrations were lower in group A versus group B, and median serum FSH, testosterone and androstenedione concentrations were higher in group A versus group B, throughout the follicular phase, without reaching significance. Median endometrial thickness was significantly higher (P < 0.05) in group A versus group B on the day of human chorionic gonadotrophin administration. Pregnancies were achieved. This pilot study supports the idea that aromatase inhibitors can contribute to normal potential of implantation and follicular response, without having negative anti-oestrogenic effects.

A prospective randomized trial comparing anastrozole and clomiphene citrate in an ovulation induction protocol using gonadotropins

OBJECTIVE

To compare the ovarian and endometrial effects of anastrozole and clomiphene when used with gonadotropins in a combination protocol.

DESIGN

Prospective randomized trial.

SETTING

Academic infertility center.

PATIENT(S)

Fifty infertile women.

INTERVENTIONS(S)

Women were randomized to receive either 1 mg anastrozole or 100 mg clomiphene citrate for 5 days (cycle days 3-7) followed by FSH injections (days 7-11) for ovulation induction. A subset participated in a crossover arm of the study.

MAIN OUTCOME MEASURE(S)

Ovarian follicle number and size, E(2) levels, endometrial thickness, pregnancy, and cancellation rates.

RESULT(S)

On cycle day 12, anastrozole cycles were associated with fewer total follicles (1.4 vs. 3.6, P=0.01), fewer mature follicles (0.6 vs. 1.6, P<.01), lower serum E(2) (131 pg/mL vs. 613 pg/mL, P<.01,) and the same endometrial stripe thickness compared with clomiphene citrate cycles. Cycle cancellation rates were similar between the two groups. On the day of hCG administration in noncancelled cycles, anastrozole cycles were associated with fewer total follicles (1.6 vs. 3.8, P<.01), fewer mature follicles (1.3 vs. 2.1, P<.01), and an equal endometrial stripe thickness compared with clomiphene citrate cycles. Pregnancy rates were similar between clomiphene (20%) and anastrozole (12%) cycles.

CONCLUSION(S)

Anastrozole when used in conjunction with gonadotropins results in lower E(2) levels and fewer follicles than clomiphene citrate. A combination protocol of anastrozole and gonadotropins may be a safer protocol for patients at higher risk of hyperstimulation and multiple births after infertility treatments.

Comparison of the efficacy of the aromatase inhibitor letrozole and clomiphene citrate as adjuvants to recombinant follicle-stimulating hormone in controlled ovarian hyperstimulation: a prospective, randomized, blinded clinical trial

OBJECTIVE

To study the efficacy of the aromatase inhibitor letrozole as adjuvant to recombinant FSH (rFSH) in controlled ovarian hyperstimulation (COH).

DESIGN

Prospective, randomized, and blinded clinical study.

SETTING

Academic tertiary institute.

PATIENT(S)

Forty-one patients with unexplained infertility undergoing intrauterine insemination (IUI) therapy were randomized to receive either letrozole or clomiphene citrate (CC) as adjuvants to rFSH.

INTERVENTION(S)

From day 3 to 7 of the cycle 2.5 mg/d letrozole or 100 mg/d CC were administrated. All patients received 75 IU rFSH starting on day 7 of stimulation until the day of hCG administration. Ovulation was triggered with recombinant hCG (250 microg) when the leading follicle(s) reached 18 mm in diameter. A single IUI was performed 36 hours later. The luteal phase was supplemented with micronized progesterone vaginally.

MAIN OUTCOME MEASURE(S)

Ovarian stimulation response (E(2) levels and number of follicles) was our primary outcome.

RESULT(S)

There were no differences in demographic characteristics between groups. Although there was a significantly lower peak serum E(2) level in the group receiving letrozole + rFSH compared with CC + rFSH (914 +/- 187 vs. 1,207 +/- 309 pg/mL, respectively; P<.007), there were no differences in the number of mature (>16 mm) preovulatory follicles. A significantly higher endometrial thickness was observed at the time of hCG administration in patients that received letrozole (9.5 +/- 1.5 mm vs. 7.3 +/- 1.1 mm; P=.0001). The clinical pregnancy rate was similar between groups (23.8% vs. 20%, respectively).

CONCLUSION(S)

The aromatase inhibitor letrozole appears to constitute a good alternative to CC in patients with unexplained infertility undergoing gonadotropin-stimulated COH cycles combined with IUI therapy.

Use of an aromatase inhibitor in patients with polycystic ovary syndrome: a prospective randomized trial

OBJECTIVE

To compare the use of an aromatase inhibitor (letrozole) with the use of clomiphene citrate (CC).

DESIGN

Prospective randomized study.

SETTING

An infertility clinic in a university hospital.

PATIENT(S)

Seventy-four consecutive infertile patients with polycystic ovary syndrome were recruited. Thirty-eight patients were randomized to the letrozole group (99 cycles), and the remaining patients were recruited to the CC group (95 cycles).

INTERVENTION(S)

The aromatase inhibitor letrozole (2.5 mg/d) and CC (100 mg/d) were administered orally on days 3-7 of menses.

MAIN OUTCOME MEASURE(S)

Number of follicles, endometrial thickness, E(2) levels on hCG day, and pregnancy rates among both groups.

RESULT(S)

Ovulation occurred in 65.7% (65/99) of letrozole cycles and in 74.7% (71/95) of CC cycles. The median (minimum-maximum) number of follicles sized >15 mm in diameter on the day of hCG administration were 1 (0-4) and 1 (0-5) in the letrozole and CC groups, respectively. On the day of hCG administration, median serum E(2) concentrations in the letrozole and CC groups were statistically significantly different: 189 pg/mL (18-1,581 pg/mL) and 386 pg/mL (27-6,190 pg/mL), respectively. The median serum E(2) concentrations per follicle sized >15 mm in diameter on the day of hCG also statistically significantly differed between the letrozole and CC groups: 160 pg/mL (18-808 pg/mL) and 281 pg/mL (27-2,615 pg/mL), respectively. The median endometrial thickness on the day of hCG did not significantly differ between the CC and letrozole groups; it was 8 mm. Pregnancy was achieved in nine cycles (9.1%) of the letrozole group and in seven cycles (7.4%) of the CC group, which also was not a statistically significant difference.

CONCLUSION(S)

The aromatase inhibitor letrozole may be an acceptable alternative to CC as an ovulation-induction drug in patients with PCOS.

Preliminary experience with a low-cost stimulation protocol that includes letrozole and human menopausal gonadotropins in normal responders for assisted reproductive technologies

A low-cost stimulation protocol that includes letrozole and hMG in normal responders for assisted reproductive technologies resulted in a satisfactory ongoing pregnancy rate.

Role of aromatase inhibitor in ovulation induction in patients with poor response to clomiphene citrate

AIM

To examine the efficacy of aromatase inhibitor in the induction of ovulation.

METHODS

This prospective clinical trial in patients with infertility and poor response to clomiphene citrate (CC) was undertaken in a tertiary referral infertility clinic. Thirty-five infertile patients, who were treated by clomiphene citrate for several cycles and referred to the infertility clinic, were the target population. Initially, the response of CC was assessed by same dose of CC that the patient had in her last cycle. The patients who did not respond adequately were treated by aromatase inhibitor 2.5-5 mg/day from day 3-7 of the menstrual cycle. The main outcome measures were the number of mature follicles, ovulation rate, endometrial thickness and pregnancy rate.

RESULTS

Twenty-seven (90%) patients developed mature follicles by day 12. The majority (77.77%) developed single follicle. Except for one cycle of one patient, the follicles of all patients were ruptured in all cycles and seven (25.94%) got pregnant.

CONCLUSION

The aromatase inhibitor letrozole is effective for ovulation induction in anovulatory infertility in patients that failed to ovulate by CC.

Cost-effectiveness of aromatase inhibitor co-treatment for controlled ovarian stimulation

BACKGROUND

To compare the clinical results and the cost-effectiveness of using the aromatase inhibitor, letrozole, in conjunction with FSH and FSH alone for controlled ovarian stimulation (COS) in patients undergoing intrauterine insemination (IUI) for a variety of indications.

METHODS

Four hundred and thirty-two consecutive patients who underwent 872 IUI cycles were included. The study population was composed of two groups. Group I included 308 patients who underwent 589 IUI cycles with letrozole and FSH for the following indications: anovulation (143 cycles), male factor infertility (147 cycles), unexplained infertility (250 cycles), endometriosis (18 cycles) and combined indications (31 cycles). Group II included 124 patients who underwent 283 IUI cycles who received FSH only for the following indications: ovarian factor infertility (82 cycles), male factor infertility (66 cycles), unexplained infertility (114 cycles), endometriosis (13 cycles) and other indications (8 cycles). Main outcome measures included number of mature follicles >16 mm in diameter, dose of FSH used per cycle, clinical pregnancy rate and cost-effectiveness ratio per pregnancy.

RESULTS

FSH dose required for ovarian stimulation was significantly lower when letrozole was used (P < 0.0001). Although a significantly higher number of follicles >16 mm and endometrial thickness at the day of hCG administration (P < 0.0001) were observed in Group II, pregnancy rate per started (14.4 versus 15.9%) and per completed cycles (15.77 versus 18.07%) was the same in Group I and Group II, respectively. IUI cancellation rate was significantly lower with letrozole treatment (P = 0.05%). The cost per cycle was significantly lower in Group I versus Group II (468.93 Can dollars +/- 418.18 versus 1067.28 +/- 921.43; P < 0.0001). The cost-effectiveness ratio was 3249.42 dollars in the letrozole group and 6712.00 dollars in the FSH-only group.

CONCLUSION

A letrozole-FSH combination could be an effective ovarian stimulation protocol in IUI cycles. Such a protocol may be more cost-effective than FSH alone because of the difference of FSH dose and cost. A randomized controlled trial is needed to further substantiate this finding.

Adjuvant Hormonal Therapy in Peri‐ and Postmenopausal Breast Cancer

Tamoxifen has been the mainstay of endocrine treatment for early-stage breast cancer in both premenopausal and postmenopausal women for many years. Since 2001, the results of several large, randomized, clinical trials have provided evidence that aromatase inhibitor (AI) therapy, either upfront or in sequence after tamoxifen, improves disease-free survival and, in certain patients, overall survival for postmenopausal patients with hormone receptor-positive breast cancer. Thus far, with relatively short-term follow-up, AIs have been generally safe and well tolerated among the population of patients treated in these adjuvant trials. However, important side effects such as musculoskeletal and bone-related problems, including the risk for osteoporosis and fractures, remain of concern and warrant continued monitoring and follow-up. Several questions regarding the appropriate AI to use and the timing of AI therapy remain unresolved, and ongoing studies will help address these issues. Caution is warranted in the use of AIs in perimenopausal women, including those that develop chemotherapy-induced amenorrhea, and clinical evidence supports the role for AI use in postmenopausal women only. Areas of active investigation include the mechanisms of resistance to endocrine therapy with tamoxifen and AIs and clinical strategies to overcome this resistance.

What role of estrogens in ovarian stimulation

Estrogens and progesterone represent the key ovarian hormones produced by the developing ovulatory follicle. Serum concentrations start to rise from the mid-follicular phase onwards, coinciding with the development of the dominant follicle. Androgens are converted into estrogens by aromatase activity of the granulosa cells and secreted into the follicular fluid compartment. Their significance for oocyte maturation and fertilizing potential remains unknown. Paradoxically, serum estrogen levels are within the normal range in the majority of patients presenting with cycle abnormalities due to ovarian dysfunction. Similarly, the distribution of estradiol (E2) and follicle-stimulating hormone (FSH) levels within the normal range is comparable between normo-ovulatory controls and normogonadotropic anovulatory women. Moreover, E2 levels are only moderately correlated with luteïnizing hormone (LH), testosterone (T), androstenedione (A), sex hormone binding globulin (SHBG), the free androgen index (FAI) and finally ovarian volume as measured by ultrasound. No correlations could be found between E2 and age, body weight and cycle history and FSH. Androgen concentrations and cycle history--but not E2--were the most prominent predictors of ovarian response tot the conventional ovulation induction. Anti-estrogenic compounds like clomiphene citrate and tamoxifen have remained the first-line treatment of choice for anovulation. Certainly, CC and to a lesser extent tamoxifen have demonstrated to exhibit undesired anti-estrogenic properties at the uterine level however. However, large follow-up studies demonstrate cumulative ovulation rates around 75%, and the overall pregnancy rates of around 50%. Aromatase inhibitors, another way to interfere with estrogen feedback, represent a feasible option. This claim should, however, be substantiated by further sufficiently powered, controlled studies, and the possibility of embryo toxicity remains a major concern. In retrospect, CC and tamoxifen represent the first generation of selective estrogen receptor modulators (SERMs), and many new compounds have recently been introduced into the clinic or are currently under investigation. The major focuses of these compounds are bone density, the cardiovascular system and breast cancer. No studies have been reported in the area of ovarian stimulation.

Polycystic ovarian syndrome--prognosis and outcomes

Polycystic ovarian syndrome (PCOS) is a condition that is present in 5-6% of women of reproductive age. It has potentially profound implications for women with regard to anovulatory infertility and symptoms related to elevated androgen levels. In addition, in later life women are prone to significant health problems related to hyperinsulinaemia, with an excess risk for diabetes and cardiovascular risk factors. Evidence suggests that the adverse features of PCOS can be ameliorated with lifestyle intervention, such as diet and exercise, while further short-term benefits related to ovulation and cardiac risk factors may be derived from medication with metformin. Evidence for the long-term use of metformin to protect against adverse cardiovascular outcomes and for the use of metformin throughout pregnancy to reduce the risk of miscarriage, gestational diabetes, pre-eclampsia and fetal macrosomia is still lacking.

Adjuvant Aromatase Inhibitors for Early Breast Cancer After Chemotherapy-Induced Amenorrhoea: Caution and Suggested Guidelines

Purpose

Aromatase inhibitors (AIs) are now established as adjuvant therapy for early hormone receptor–positive breast cancer in postmenopausal women. Their use is sometimes extended to younger women after chemotherapy-induced amenorrhoea; we have audited this in one institution's breast unit, and we propose guidelines for use in such circumstances.

Patients and Methods

The use of aromatase inhibitors as adjuvant therapy in younger women age ≥ 40 with hormone receptor–positive early breast cancer and chemotherapy-induced amenorrhea has been audited clinically and biochemically.

Results

A total of 45 such women were identified in the audit, with a median age of 47 years (range, 39 to 52 years). Twelve women (27%) showed a return of ovarian function (10 renewed menses, one pregnancy, one biochemically premenopausal) after starting an AI. Median age at restart of ovarian function was 44 years (range, 40 to 50 years).

Conclusion

AIs may promote recovery of ovarian function in some women with chemotherapy-induced amenorrhea and should be used with caution. Biochemical monitoring of ovarian function requires highly sensitive immunoassays. Guidelines for the selection and delivery of adjuvant endocrine therapy in such patients are proposed.

Comparison of letrozole and clomiphene citrate in women with polycystic ovaries undergoing ovarian stimulation

Letrozole was compared with clomiphene citrate (CC) as a first-line treatment for ovulation induction in women with polycystic ovaries (PCOs). A total of 106 women with primary infertility and a diagnosis of PCOs were randomized to receive either 100 mg CC (n = 55) or 2.5 mg letrozole (n = 51) daily for 5 days. Human chorionic gonadotrophin (hCG) at a dose of 10000 IU was administered when at least one follicle with a mean diameter > or = 18 mm was observed using transvaginal ultrasound. The number of mature follicles was significantly lower, but endometrial thickness and ovulation and pregnancy rates were significantly higher in the letrozole group than in the CC group. In conclusion, letrozole is associated with a higher pregnancy rate than CC in PCO patients and may have a role as a first-line treatment for anovulatory patients with PCOs.

Letrozole induction of ovulation in women with clomiphene citrate-resistant polycystic ovary syndrome may not depend on the period of infertility, the body mass index, or the luteinizing hormone/follicle-stimulating hormone ratio

Letrozole induction of ovulation in clomiphene citrate-resistant women with polycystic ovary syndrome is associated with an ovulation rate of 54.6% and pregnancy rate of 25%. There was no significant difference between letrozole responders and nonresponders in age, period of infertility, body mass index, waist circumference, LH, FSH, or LH/FSH ratio.

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.

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.

DESIGN

Prospective pilot study.

SETTING

One university hospital and two private infertility clinics.

PATIENT(S)

Ninety-three infertile couples eligible for superovulation and IUI.

INTERVENTION(S)

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.

MAIN OUTCOME MEASURE(S)

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.

RESULT(S)

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%).

CONCLUSION(S)

Letrozole produced a comparable pregnancy rate vs. CC in gonadotropin-combined IUI cycles. Our results should be confirmed in larger populations with proper randomization.

Ovarian feedback, mechanism of action and possible clinical implications

The secretion of gonadotrophins from the pituitary in women is under ovarian control via negative and positive feedback mechanisms. Steroidal and non-steroidal substances mediate the ovarian effects on the hypothalamic-pituitary system. During the follicular phase of the cycle, estradiol (E(2)) plays a key role, while circulating progesterone (at low concentrations) and inhibin B contribute to the control of LH and FSH secretion respectively. During the luteal phase, both E(2) and progesterone regulate secretion of the two gonadotrophins, while inhibin A plays a role in FSH secretion. The intercycle rise of FSH is related to changes in the levels of the steroidal and non-steroidal substances during the luteal-follicular transition. In terms of the positive feedback mechanism, E(2) is the main component sensitizing the pituitary to GnRH. Activity of a non-steroidal ovarian substance, named gonadotrophin surge-attenuating factor (GnSAF), has been detected after ovarian stimulation. It is hypothesized that GnSAF, by antagonizing the sensitizing effect of E(2) on the pituitary, regulates the amplitude of the endogenous LH surge at midcycle. Disturbances in the feedback mechanisms can occur in various abnormal conditions or after treatment with pharmaceutical compounds that interfere with the production or the action of endogenous hormones.

Congenital malformations among 911 newborns conceived after infertility treatment with letrozole or clomiphene citrate

OBJECTIVE

To evaluate the incidence of congenital malformations among offspring of mothers who conceived with clomiphene citrate (CC) or with letrozole treatment for infertility.

DESIGN

Retrospective study.

SETTING

5 fertility centers in Canada.

PATIENTS

911 newborns from women who conceived following CC or letrozole treatment.

INTERVENTIONS

Examination of medical files of both mother and newborn, and cross-checked with the parents by telephone calls.

MAIN OUTCOME MEASURES

Identified major and minor congenital malformations, birth weight, age of the mother, and type of treatment that led to the conception.

RESULTS

Overall, congenital malformations and chromosomal abnormalities were found in 14 of 514 newborns in the letrozole group (2.4%) and in 19 of 397 newborns in the CC group (4.8%). The major malformation rate in the letrozole group was 1.2% (6/514) and in the CC group was 3.0% (12/397). One newborn in the letrozole group was found to have a ventricular septal defect (0.2%) compared to 4 newborns in the CC group (1.0%). In addition, the rate of all congenital cardiac anomalies was significantly higher (P: 0.02) in the CC group (1.8%) compared to the letrozole group (0.2%).

CONCLUSION

There was no difference in the overall rates of major and minor congenital malformations among newborns from mothers who conceived after letrozole or CC treatments. However, it appears that congenital cardiac anomaly is less frequent in the letrozole group. The concern that letrozole use for ovulation induction could be teratogenic is unfounded based on our data.

Aromatase inhibitors: the next generation of therapeutics for endometriosis?

OBJECTIVE AND DESIGN

To review the role of aromatase inhibitors (AIs) in the treatment of endometriosis.

CONCLUSION(S)

Endometriosis is a common estrogen-dependent disorder that can result in substantial morbidity, including pelvic pain, multiple operations, and infertility. Approximately only half of women with endometriosis get pain relief from existing medical or surgical treatments. Medical treatments usually are directed at inhibiting estrogen action or its production from the ovaries and do not address local estrogen biosynthesis by the aromatase enzyme in endometriotic lesions. A single gene encodes aromatase, which is the final enzyme in the estrogen biosynthesis pathway, and its inhibition effectively eliminates estrogen production. The recently introduced highly specific AIs have successfully treated pelvic pain and significantly reduced the lesion size. In premenopausal women, an AI alone may induce ovarian folliculogenesis, and thus AIs are combined with a progestin, a combination oral contraceptive, or a GnRH analogue. The side-effect profile of AIs administered in combination with an oral contraceptive or a progestin is remarkably benign. We review herein the published clinical evidence for the use of AIs in the treatment of endometriosis.

The science behind 25 years of ovarian stimulation for in vitro fertilization

To allow selection of embryos for transfer after in vitro fertilization, ovarian stimulation is usually carried out with exogenous gonadotropins. To compensate for changes induced by stimulation, GnRH analog cotreatment, oral contraceptive pretreatment, late follicular phase human chorionic gonadotropin, and luteal phase progesterone supplementation are usually added. These approaches render ovarian stimulation complex and costly. The stimulation of multiple follicular development disrupts the physiology of follicular development, with consequences for the oocyte, embryo, and endometrium. In recent years, recombinant gonadotropin preparations have become available, and novel stimulation protocols with less detrimental effects have been developed. In this article, the scientific background to current approaches to ovarian stimulation for in vitro fertilization is reviewed. After a brief discussion of the relevant aspect of ovarian physiology, the development, application, and consequences of ovarian stimulation strategies are reviewed in detail.

Letrozole vs. clomiphene citrate in patients with ovulatory infertility

OBJECTIVE

To compare the effectiveness of letrozole and clomiphene citrate (CC) in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility.

DESIGN

Prospective quasi-randomized trial.

SETTING

University infertility clinic.

PATIENT(S)

Forty-six consecutive patients with ovulatory infertility were recruited. Twenty-five patients (67 cycles) were given CC and 21 patients (52 cycles) were given letrozole. Both drugs were given orally on days 3-7 of menses.

INTERVENTION(S)

Letrozole, CC, ovulation induction, IUI, timed intercourse.

MAIN OUTCOME MEASURE(S)

Number of follicles, endometrial thickness, and pregnancy rates.

RESULT(S)

The median serum E2 concentration on the day of hCG administration in the letrozole and CC groups were 191.5 pmol/L and 476.0 pmol/L, respectively. The median endometrial thickness on the day of hCG were 8 mm in both groups. Ovulation occurred in 81% (42/52) of the letrozole-treated and 85% (57/67) of the CC-treated patients. Pregnancy rate (PR) per cycle was 9% (5/52) in the letrozole group and 12% (8/67) in the CC group.

CONCLUSION(S)

Letrozole and CC have comparable effectiveness in ovulatory patients with borderline male factor infertility, early stage endometriosis, and unexplained infertility.

Review: aromatase inhibitors for ovulation induction

CONTEXT

For the last 40 yr, the first line of treatment for anovulation in infertile women has been clomiphene citrate (CC). CC is a safe, effective oral agent but is known to have relatively common antiestrogenic endometrial and cervical mucous side effects that could prevent pregnancy in the face of successful ovulation. In addition, there is a significant risk of multiple pregnancy with CC, compared with natural cycles. Because of these problems, we proposed the concept of aromatase inhibition as a new method of ovulation induction that could avoid many of the adverse effects of CC. The objective of this review was to describe the different physiological mechanisms of action for CC and aromatase inhibitors (AIs) and compare studies of efficacy for both agents for ovulation induction.

EVIDENCE ACQUISITION

We conducted a systematic review of all the published studies, both controlled and noncontrolled, comparing CC and AI treatment, either alone or in combination with gonadotropins, for ovulation induction or augmentation, identified through the Entrez-PubMed search engine.

EVIDENCE SYNTHESIS

Because of the recent acceptance of the concept of using AIs for ovulation induction, few controlled studies were identified, and the rest of the studies were pilot or preliminary comparisons. Based on these studies, it appears that AIs are as effective as CC in inducing ovulation, are devoid of any antiestrogenic side effects, result in lower serum estrogen concentrations, and are associated with good pregnancy rates with a lower incidence of multiple pregnancy than CC. When combined with gonadotropins for assisted reproductive technologies, AIs reduce the dose of FSH required for optimal follicle recruitment and improve the response to FSH in poor responders.

CONCLUSIONS

Preliminary evidence suggests that AIs may replace CC in the future because of similar efficacy with a reduced side effect profile. Although worldwide experience with AIs for ovulation induction is increasing, at present, definitive studies in the form of randomized controlled trials comparing CC with AIs are lacking.

Efficacy of combined metformin–letrozole in comparison with metformin–clomiphene citrate in clomiphene-resistant infertile women with polycystic ovarian disease

BACKGROUND

Adding metformin to clomiphene citrate in clomiphene-resistant polycystic ovary syndrome (PCOS) patients increases ovulatory response. However, because of anti-estrogenic effects of clomiphene it may be associated with lower pregnancy rate, offsetting the ovulation rate benefit. Letrozole is an aromatase inhibitor which induces ovulation without anti-estrogenic effects.

METHODS

Infertile women with PCOS were randomly divided into metformin-letrozole (29 patients) and metformin-clomiphene groups (30 patients). After an initial 6-8 weeks of metformin, they received either letrozole (2.5 mg) or clomiphene (100 mg) from day 3-7 of their menstrual cycle. Estradiol (E2) levels, number of follicles, pregnancy rates and endometrial thickness were measured on the day of HCG administration.

RESULTS

Mean total E2 and E2 per mature follicle were significantly higher in clomiphene group without a difference in mean number of mature follicles >18 mm and ovulation rate. Endometrial thickness was significantly higher in letrozole group. The pregnancy rate in letrozole group (10 patients, 34.50%) as compared with clomiphene group (5 patients, 16.67%) did not show significant difference, whereas full-term pregnancies were higher in letrozole group [10 patients (34.50%) versus 3 patients (10%)].

CONCLUSION

In clomiphene-resistant PCOS patients, the combination of letrozole and metformin leads to higher full-term pregnancies.

What can the clinician do to improve implantation?

Implantation is a complicated process that requires the orchestration of a series of events involving both the embryo and the endometrium. Even with the transfer of high quality embryos, implantation rates remain relatively low. The growing tendency towards transferring fewer embryos provides further incentives to improve implantation rates. In this article, the various clinical strategies employed to increase the chance of implantation are reviewed. Embryo transfer technique is a critical step in assisted reproductive technology cycles. Recent studies have shown significant improvements in clinical pregnancy rates resulting from careful embryo transfer technique, appropriate catheter type and placing for embryo transfer. Increasingly, adjuvant pharmaceutical therapies are also being applied with the aim of improving embryo implantation. However, the evidence for their efficacy and safety is limited. Recent evidence suggests that adoption of milder ovarian stimulation regimens may provide a more effective clinical approach to improving implantation, since beneficial effects have been shown for both endometrial receptivity and embryo quality.

Letrozole versus human menopausal gonadotrophin in women undergoing intrauterine insemination

This pilot study was conducted to compare the results of intrauterine insemination (IUI) under ovarian stimulation with either letrozole (Femara) or human menopausal gonadotrophin (HMG). A randomized controlled trial was conducted. Eighty women aged 20-35 years with unexplained infertility of at least 2 years' duration were randomized according to a computer-generated randomization list into the letrozole group and the HMG group. Letrozole was administered at 5 mg/day from day 3 to day 7 of the IUI cycle. HMG injections were started on day 3 at a dose of 75 IU for women under 30 years old and 150 IU for women over 30 years old and monitored periodically by vaginal ultrasound and oestradiol concentrations. The variables selected for analysis were clinical pregnancy rate, endometrial thickness, length of follicular phase and number of preovulatory follicles. No statistically significant difference in clinical pregnancy rates per cycle was found for patients in the letrozole or HMG group (18.4 versus 15.7%). Cost was significantly higher in the HMG stimulation cases (P < 0.001) and no injections were required in the letrozole group. In conclusion, letrozole offers a new treatment regimen in ovarian stimulation regimens for IUI that is cost effective, simple and convenient for the patients.

A randomized trial of superovulation with two different doses of letrozole

OBJECTIVE

The aim of this study was to evaluate the effects of either a 2.5-mg or a 5-mg daily dose of letrozole in women undergoing superovulation and intrauterine insemination (IUI).

DESIGN

Prospective randomized trial.

SETTING

Academic teaching hospital.

PATIENT(S)

Women <40 years old, with patent fallopian tubes and infertility of >1 year in duration.

INTERVENTION(S)

Patients were randomized into either a 2.5-mg dose of letrozole (34 patients) or a 5-mg dose of letrozole (38 patients) daily for 5 days. When the leading follicle reached 18 mm in diameter, ovulation was triggered by an injection of hCG and IUI was performed 24 and 48 hours later.

MAIN OUTCOME MEASURE(S)

The number of follicles, endometrial thickness, and pregnancy rate.

RESULT(S)

Compared with those treated with 2.5 mg of letrozole, the total number of follicles was significantly higher in patients receiving 5 mg of letrozole. No difference in the endometrial thickness was found between the two groups. The pregnancy rate per cycle in patients receiving 5mg of letrozole was statistically higher than in patients receiving 2.5 mg of letrozole (26.3% vs. 5.9%, P<.05). No multiple pregnancies occurred.

CONCLUSION(S)

Compared with the daily dose of 2.5 mg, 5 mg of letrozole is associated with more follicles and a higher pregnancy rate. It appears that 5 mg daily for 5 days is a preferable letrozole dose for superovulation.

Therapeutic strategies for ovulation induction in infertile women with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) is a heterogeneous disorder characterized by hirsutism, obesity, hyperandrogenism and insulin resistance. The syndrome is often accompanied by infertility because of anovulation. Many approaches have been proposed to solve this problem, with the most commonly used therapies being ovarian drilling and pharmacological ovulation induction. Ovarian drilling is a procedure in which a laser fiber or electro-surgical needle punctures the ovary four to ten times. Side-effects are rare and often related to surgery itself. Pharmacological strategies include administration of metformin and insulin-sensitizing agents, clomiphene citrate (CC), gonadotropins and aromatase inhibitors. Metformin appears valuable in increasing ovulation rate, menstrual cyclicity and pregnancy rate. CC is an oral estrogen antagonist that raises circulating concentrations of follicle-stimulating hormone (FSH) and induces follicular growth in most women with PCOS and anovulation. Failure to respond is associated with high body mass index and high androgen levels. Aromatase inhibitors mimic the central reduction of negative feedback through which CC works. Ovulation induction with recombinant FSH has proved successful, but treatment requires skill and experience to avoid multiple pregnancies and ovarian hyperstimulation syndrome. The hypothetical deleterious effects of the high luteinizing hormone concentrations observed in PCOS patients seem to be related to the concomitant hyperinsulinemia (and/or insulin resistance). A thorough understanding of the syndrome and a careful assessment of each patient are the mainstays for choosing an appropriate treatment regimen.

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment

Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality.

Addressing the growing problem of multiple gestations created by assisted reproductive therapies

Iatrogenic multiple pregnancy is the most significant complication of assisted reproductive technology (ART). Approximately half of all children born subsequent to ART result from a plural gestation. Furthermore, the majority of triplets and higher order births are the product of ART. The risks for multiple pregnancy vary with practice patterns and the techniques used to achieve pregnancy. Recognizing the potential for serious morbidity associated with multiple pregnancies, infertility specialists have developed strategies to reduce the complication of multiple pregnancies while maintaining acceptable pregnancy rates. Implementation of these refined practices has led to a reduction in the incidence of higher order multiple births, although the incidence of twins has yet to be minimized. Further reduction in the incidence of multiple births after ART necessitates a redefinition of success to emphasize the healthy singleton birth rate, rather than crude pregnancy rates.

A meta-analysis of outcomes of conventional IVF in women with polycystic ovary syndrome

This meta-analysis was conducted to compare outcomes of conventional IVF in women presenting with polycystic ovary syndrome (PCOS) and non-PCOS patients. Studies in which PCOS patients undergoing IVF were compared with a matched--no male factor--control group were considered for this review. A definition consistent with the Rotterdam consensus criteria of PCOS was required, and all patients within a given study had to be treated with the same ovarian stimulation protocol. Information regarding patient characteristics and pregnancy outcome was also required. Nine out of 290 identified studies reporting data on 458 PCOS patients (793 cycles) and 694 matched controls (1116 cycles) fulfilled these inclusion criteria. PCOS patients demonstrated a significantly reduced chance of oocyte retrieval per started cycle, odds ratio (OR) = 0.5 [95% confidence interval (CI) = 0.2-1.0]. However, no difference was observed in chance of embryo transfer per oocyte retrieval between the groups (OR = 0.7, 95% CI = 0.4-1.3). Significantly more oocytes per retrieval were obtained in PCOS patients compared with controls [random effects estimate 3.4 [95% (CI) = 1.7-5.1)]. The number of oocytes fertilized did not differ significantly between PCOS patients and controls, weighted mean difference (WMD) 0.1 oocytes (95% CI = 21.4-1.6). No significant difference was observed in the clinical pregnancy rates per started cycle, OR = 1.0 (95% CI = 0.8-1.3). The incidence of ovarian hyperstimulation syndrome (OHSS) after oocyte retrieval was rarely reported. This meta-analysis demonstrates an increased cancellation rate, but more oocytes retrieved per retrieval and a lower fertilization rate in PCOS undergoing IVF. Overall, PCOS and control patients achieved similar pregnancy and live birth rates per cycle.

Aromatase inhibitors: rationale and use in breast cancer

Considerable data implicate estrogens in breast cancer carcinogenesis and progression. In the postmenopausal woman, estrogens are produced in breast tissues and many other sites throughout the body when androgen precursors are converted into estrogens via the enzyme aromatase. Inhibition of this enzyme with aromatase inhibitors (AIs) has demonstrated reductions in systemic as well as intratumoral estrogens. These drugs have now been utilized in large phase 3 randomized trials and have led to greater improved clinical benefit than the "gold standard," tamoxifen. Questions remain about the long-term side effects and safety profile of AIs. They are associated with increasing incidence of osteoporosis and bone fractures. Nevertheless, AIs add to our armamentarium for therapy and possible prevention of breast cancer.

Individualized cost-effective conventional ovulation induction treatment in normogonadotrophic anovulatory infertility (WHO group 2)

BACKGROUND

Conventional treatment in normogonadotrophic anovulatory infertility (WHO 2) consists of clomiphene citrate (CC), followed by exogenous gonadotrophins (FSH) and IVF. Response to these treatments may be predicted on the basis of individual patient characteristics. We aimed to devise a patient-tailored, cost-effective treatment algorithm involving the above-mentioned treatment modalities, based on individual patient characteristics.

METHODS

Sixteen prognostic groups are defined, according to the presence or absence of: age >30 years, amenorrhea, elevated androgen levels and obesity. The chances of response with each of the three treatments were calculated using prediction models. Treatment costs were based on the data of 240 patients visiting a specialist academic fertility unit. Outcome was an ongoing pregnancy within 12 months after initiation of treatment. The costs per pregnancy of three different strategies were compared, with a threshold for cost-effectiveness of 10 000.

RESULTS

The strategy CC + FSH + IVF compared with FSH + IVF generated more pregnancies against lower costs. Compared with CC + IVF, it also produced more pregnancies, but at higher costs. For <30 years of age with normal androgen levels, costs per pregnancy were less than 10 000. For women >30 years old, costs per pregnancy were 25 000 and over 200 000, when presenting with normal or elevated androgen levels, respectively.

CONCLUSIONS

The conventional treatment protocol is efficient for women aged <30 years with normal androgen levels. For women >30 years old with elevated androgen levels, FSH may be skipped.

Ovulation induction: a mini review

Ovulation induction is the method for treating anovulatory infertility. For patients with hypogonadotrophic hypogonadism, the treatment involves administration of both FSH and LH, while HCG is injected for follicle rupture. Pulsatile GnRH has the same effectiveness as gonadotrophins and the advantage of the low multiple pregnancy rate. In polycystic ovary syndrome (PCOS), the first treatment choice is clomiphene citrate. With this drug, in properly selected patients, the cumulative pregnancy rate approaches that of normal women. Low-dose protocols of FSH are the second line of treatment, effective in inducing monofollicular development. Laparoscopic ovarian drilling can be an alternative but not as a first choice treatment in clomiphene-resistant patients. Other treatments, such as pulsatile GnRH and GnRH agonists, are hardly used today in PCOS. However, in obese women with PCOS, weight loss and exercise should be recommended as the first line of therapy. Newer agents including aromatase inhibitors and insulin sensitizers, although promising, need further evaluation.

Irregular cycles and steroid hormones in polycystic ovary syndrome

BACKGROUND

This cross-sectional study was undertaken to evaluate the factors that relate to menstrual status (oligo-amenorrhoea versus eumenorrhoea) in polycystic ovary syndrome (PCOS).

METHODS

A total of 234 women with clinical and biochemical features suggestive of PCOS underwent metabolic and hormonal evaluation. A forward stepwise logistic regression model was created based on the results to determine variables related to ovulatory status.

RESULTS

Only follicular phase progesterone and estradiol (E(2)) were retained in the final model. This model correctly classified 80% of PCOS women by ovulatory status. Univariate analysis revealed no difference in progesterone between ovulatory groups but E(2) was higher in anovulatory groups. This suggested interaction between progesterone and E(2) and the single interaction variable (progesterone/E(2)) also classified 80% of women by ovulatory status correctly.

CONCLUSION

The results suggest that a low ratio of progesterone to E(2) is associated with menstrual irregularity and ovulatory status in PCOS.

Clomiphene citrate--end of an era? A mini-review

The purpose of this review is to examine whether the time has come to replace clomiphene citrate (CC) as the first line therapy for WHO group II (eu-oestrogenic) infertility, the majority of which is associated with polycystic ovary syndrome. CC has been the first line therapy for these cases for the last 40 years. It is a simple, cheap treatment, almost devoid of side effects which yields a single live birth rate of approximately 25% of starters. Non-response to CC and the gap between ovulation and pregnancy rates have variously been attributed to its anti-estrogen effects, and high LH and androgen concentrations. Three possible contenders for the replacement of CC as first-line treatment are scrutinized: metformin, aromatase inhibitors and low-dose FSH. Each has their advantages and disadvantages, but none of them, while showing much potential promise, has been proven, as yet, to be a feasible replacement for CC in this role. For CC, it may not yet be the end of an era but it may be the beginning of the end.

Clinical use of aromatase inhibitors (AI) in premenopausal women

Aromatase inhibitors (AI) block the last enzymatic step of estrogen production, the aromatization of the A-cycle of aromatizable androgens and particularly, androstenedione (delta4) and testosterone (T). Molecules designed for interfering with aromatase activity have existed for many years. Yet the activity of products of the aminogluthetimide era was unspecific and these substances carried too many side effects for being used clinically. Newer third generation AIs, however, are highly specific and essentially devoid of side effects. These molecules have recently been approved for treating breast cancer in postmenopausal women either, in advanced forms or, as part of adjuvant therapy. In women whose ovaries are active, a temporary inhibition of E2 production will raise gonadotropins and in turn, stimulate follicular growth. In cancer patients, this property precludes the use of AIs in women whose ovaries are still active, unless gonadotropins are blocked. But in infertility patients, this property of AIs has been put to play for inducing ovulation. AIs have been used both in women who do not ovulate but whose hypothalamo-pituitary-gonadal (HPG) axis is active (oligo-anovulators of PCOD type) and those who ovulate regularly but in whom multiple ovulation is sought for treating unexplained infertility or as part of IVF. Like clomiphene citrate (CC), AIs are not usable in women whose gonadotropins are suppressed, as in the case of hypothalamic amenorrhea. The sum of data available on the use of AI for inducing ovulation remains however meager to this date and is mainly constituted of pilot and non-randomized trials. Yet mounting evidence tends to support AIs' advantages over CC for induction of ovulation. Hence, we think that the likelihood that these drugs will play a key role in induction of ovulation in the future is high. AIs appear particularly interesting for treating unexplained infertility because AI-FSH/hMG regimens are lighter than FSH-only regimens while retaining the high pregnancy rates of these latter treatments.

[Use of aromatase inhibitors in infertile women]

Aromatase inhibitors (AI) block the last enzymatic step of estrogen production, the aromatization of the A-cycle of aromatizable androgens and particularly, androstenedione (D4) and testosterone (T). Molecules designed for interfering with aromatase activity have existed for many years. Yet the activity of products of the aminogluthetimide era was too unspecific and these substances carried too many side effects for being used clinically. Today, however, 3rd generation AIs have become available that are highly specific and essentially devoid of side effects. These molecules have recently been approved for treating breast cancer in post-menopausal women, either in advanced forms, or as part of adjuvant therapy. In women whose ovaries are active, a temporary inhibition of E2 production will activate gonadotropins and in turn, stimulate follicular growth. In cancer patients, this property precludes the use of AIs in women whose ovaries are still active, unless gonadotropins are blocked. In infertile patients, this property of AIs has been put to play for inducing ovulation. AIs have been used both in women who do not ovulate but whose hypothalamo-pituitary-gonadal (HPG) axis is active (oligo-anovulators of PCOD type) and in those who ovulate regularly but in whom multiple ovulation is sought for treating infertility or as part of IVF. Like CC, AIs are not usable in women whose gonadotropins are suppressed, as in the case of hypothalamic amenorrhea. The sum of data available on the use of AI for inducing ovulation remains however meager to this date and is mainly constituted of pilot and non-randomized trials. Yet mounting evidence tends to support AIs' advantages over CC for induction of ovulation. Hence, we think that these drugs will play a key role for the induction of ovulation in the future.

Ovulation induction

Anovulation, a common cause of female infertility, is a highly curable condition. Presented here is a simple treatment-orientated diagnostic scheme. Anovulatory women with low endogenous oestradiol and follicle stimulating hormone (FSH) are treated with either pulsatile gonadotrophin releasing hormone (GnRH) or gonadotropins, and women with eu-oestrogenic anovulation (mostly with polycystic ovarian syndrome; PCOS) have first-line treatment with clomiphene citrate (CC), possibly with metformin. If CC fails, FSH is administered using a chronic low-dose protocol with small incremental dose rises. A comparison of urinary with recombinant and pure FSH with luteinising hormone (LH) containing gonadotropins is made. Recombinant products are purer and more convenient for use but are expensive. LH content has little impact except in hypogonadotropic hypogonadism or severe pituitary suppression with GnRH analogues. Aromatase inhibitors, recombinant LH and long-acting FSH may find a future place in the armamentarium.