Comparison of the efficacy of the aromatase inhibitor letrozole and clomiphen citrate gonadotropins in controlled ovarian hyperstimulation: a prospective, simply randomized, clinical trial

Meta analysis of ovulation induction effect and pregnancy outcome of acupuncture & moxibustion combined with clomiphene in patients with polycystic ovary syndrome

Objective

Using Mesh Meta Analysis to evaluate the efficacy of Acupuncture & Moxibustion, Clomiphene, Acupuncture & Moxibustion combined with Clomiphene for treating Polycystic Ovary Syndrome (PCOS), in order to provide evidence-based medical evidence for whether to recommend Acupuncture & Moxibustion or Combine western medicine to treat PCOS.

Methods

Eight databases including The Cochrane Library, Pubmed, Embase, Web of Science, CNKI, Wanfang Date, VIP and CBM were searched by computer. The included research period is from the establishment of the database to May 2023, which concerned with randomized controlled trials involving Acupuncture & Moxibustion, Clomiphene, Acupuncture & Moxibustion combined with Clomiphene on ovulation induction and pregnancy outcome in patients with PCOS. The duration of the research paper is from 2016 to 2023.The inclusion criteria refer to the Rotterdam standards issued by the European Center for Human Reproduction and Embryology and the American Society of Reproductive Medicine in January 2003, or the Expert Consensus on the Diagnosis and Treatment of Polycystic Ovarian Syndrome by the Endocrinology Group of the Obstetrics and Gynecology Branch of the Chinese Medical Association. Simultaneously exclude related diseases, repetitive literature, as well as literature with incomplete abstract information and no original data provided. Two researchers independently screened the literature, extracted data, and evaluated the risk of bias included in the study, using Stata17.0 software for a mesh meta-analysis.

Results

Six randomized controlled trials were included, covering 1410 PCOS patients. Three interventions included Acupuncture & Moxibustion, Clomiphene, Acupuncture & Moxibustion combined with Clomiphene. Mesh Meta Analysis showed that in terms of improving ovulation rate, there was no statistical difference between Acupuncture & Moxibustion (A), Clomiphene (B), Clomiphene combined with Acupuncture & Moxibustion (C) (P>0.05).Acupuncture & Moxibustion (A) versus Clomiphene (B) [MD=0.15,95% CI (-0.51,0.80)], Acupuncture & Moxibustion (A) versus Clomiphene combined with Acupuncture & Moxibustion (C) [MD=1.60,95% CI (0.97,2.23)], Clomiphene (B) versus Clomiphene combined with Acupuncture & Moxibustion (C) [MD=1.45,95% CI (0.91,1.99)]. In terms of pregnancy outcome, the difference between the three intervention methods was statistically significant (P<0.05). Acupuncture & Moxibustion (A) versus Clomiphene (B) [MD=-0.80,95% CI (-1.84,0.23)], Acupuncture & Moxibustion (A) versus Clomiphene combined with Acupuncture & Moxibustion (C) [MD=0.29,95% CI (-0.73,1.30)], and Clomiphene (B) versus Clomiphene combined with Acupuncture & Moxibustion (C) [MD=1.09,95% CI (0.39,1.79)], The order of pregnancy rate from high to low is Acupuncture & Moxibustion combined with Clomiphene (C), Acupuncture & Moxibustion (A), Clomiphene (C).In terms of influencing endometrial thickness, the difference between the three intervention methods was statistically significant (P<0.05). Acupuncture & Moxibustion (A) versus Clomiphene (B) [MD=-0.84,95% CI (-1.87,0.19)], Acupuncture & Moxibustion (A) versus Acupuncture & Moxibustion combined with Clomiphene (C) [MD=0.26,95% CI (-1.01,1.53)], Clomiphene (B) versus Acupuncture & Moxibustion combined with Clomiphene (C) [MD=1.10,95% CI (0.36,1.84)], Acupuncture & Moxibustion combined with Clomiphene (C) has the best effect on improving endometrial thickness. In subgroup analysis, the effect of Acupuncture & Moxibustion treatment frequency on ovulation rate and pregnancy rate was not statistically significant. The combination of Acupuncture & Moxibustion, Electroacupuncture and warm Acupuncture & Moxibustion has no effect on the pregnancy rate, but the combination of Electroacupuncture and Clomiphene has the best effect on improving the ovulation rate. In the observation of adverse reactions, compared with clomiphene alone, Acupuncture & Moxibustion combined with Clomiphene can reduce the occurrence of Luteinized Unruptured Follicle Syndrome (LUFS) and Ovarian Hyperstimulation Syndrome (OHSS), and reduce the occurrence of physical adverse reactions such as nausea, vomiting, headache and dermatitis.

Conclusion

Acupuncture & Moxibustion is effective in improving the ovulation promoting effect and pregnancy outcome of PCOS patients. The ovulation promoting effect of Acupuncture & Moxibustion or combined with Clomiphene is similar to that of Clomiphene alone, but Acupuncture & Moxibustion combined with Clomiphene has more advantages in improving the pregnancy rate of PCOS, and it also can reduce the adverse reactions of Clomiphene alone. Acupuncture & Moxibustion can be used as a recommended treatment for PCOS. More cases should also be included in the subgroup analysis to study the impact of Acupuncture & Moxibustion programs on clinical efficacy and further optimize the Acupuncture & Moxibustion treatment program.

Systematic review registration

https://www.crd.york.ac.uk/PROSPERO/#myprospero, identifier (CRD42023433057).

The definition of unexplained infertility: A systematic review

BACKGROUND

There is no consensus on tests required to either diagnose unexplained infertility or use for research inclusion criteria. This leads to heterogeneity and bias affecting meta-analysis and best practice advice.

OBJECTIVES

This systematic review analyses the variability of inclusion criteria applied to couples with unexplained infertility. We propose standardised criteria for use both in future research studies and clinical diagnosis.

SEARCH STRATEGY

CINAHL and MEDLINE online databases were searched up to November 2022 for all published studies recruiting couples with unexplained infertility, available in full text in the English language.

DATA COLLECTION AND ANALYSIS

Data were collected in an Excel spreadsheet. Results were analysed per category and methodology or reference range.

MAIN RESULTS

Of 375 relevant studies, only 258 defined their inclusion criteria. The most commonly applied inclusion criteria were semen analysis, tubal patency and assessment of ovulation in 220 (85%), 232 (90%), 205 (79.5%) respectively. Only 87/220 (39.5%) studies reporting semen analysis used the World Health Organization (WHO) limits. Tubal patency was accepted if bilateral in 145/232 (62.5%) and if unilateral in 24/232 (10.3%). Ovulation was assessed using mid-luteal serum progesterone in 115/205 (56.1%) and by a history of regular cycles in 87/205 (42.4%). Other criteria, including uterine cavity assessment and hormone profile, were applied in less than 50% of included studies.

CONCLUSIONS

This review highlights the heterogeneity among studied populations with unexplained infertility. Development and application of internationally accepted criteria will improve the quality of research and future clinical care.

Agents for ovarian stimulation for intrauterine insemination (IUI) in ovulatory women with infertility

BACKGROUND

Intrauterine insemination (IUI), combined with ovarian stimulation (OS), has been demonstrated to be an effective treatment for infertile couples. Several agents for ovarian stimulation, combined with IUI, have been proposed, but it is still not clear which agents for stimulation are the most effective. This is an update of the review, first published in 2007.

OBJECTIVES

To assess the effects of agents for ovarian stimulation for intrauterine insemination in infertile ovulatory women.

SEARCH METHODS

We searched the Cochrane Gynaecology and Fertility Group trials register, CENTRAL, MEDLINE, Embase, PsycINFO, CINAHL and two trial registers from their inception to November 2020. We performed reference checking and contacted study authors and experts in the field to identify additional studies.

SELECTION CRITERIA

We included truly randomised controlled trials (RCTs) that compared different agents for ovarian stimulation combined with IUI for infertile ovulatory women concerning couples with unexplained infertility. mild male factor infertility and minimal to mild endometriosis.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures recommended by Cochrane.

MAIN RESULTS

In this updated review, we have included a total of 82 studies, involving 12,614 women. Due to the multitude of comparisons between different agents for ovarian stimulation, we highlight the seven most often reported here. Gonadotropins versus anti-oestrogens (13 studies) For live birth, the results of five studies were pooled and showed a probable improvement in the cumulative live birth rate for gonadotropins compared to anti-oestrogens (odds ratio (OR) 1.37, 95% confidence interval (CI) 1.05 to 1.79; I² = 30%; 5 studies, 1924 participants; moderate-certainty evidence). This suggests that if the chance of live birth following anti-oestrogens is assumed to be 22.8%, the chance following gonadotropins would be between 23.7% and 34.6%. The pooled effect of seven studies revealed that we are uncertain whether gonadotropins lead to a higher multiple pregnancy rate compared with anti-oestrogens (OR 1.58, 95% CI 0.60 to 4.17; I² = 58%; 7 studies, 2139 participants; low-certainty evidence). Aromatase inhibitors versus anti-oestrogens (8 studies) One study reported live birth rates for this comparison. We are uncertain whether aromatase inhibitors improve live birth rate compared with anti-oestrogens (OR 0.75, CI 95% 0.51 to 1.11; 1 study, 599 participants; low-certainty evidence). This suggests that if the chance of live birth following anti-oestrogens is 23.4%, the chance following aromatase inhibitors would be between 13.5% and 25.3%. The results of pooling four studies revealed that we are uncertain whether aromatase inhibitors compared with anti-oestrogens lead to a higher multiple pregnancy rate (OR 1.28, CI 95% 0.61 to 2.68; I² = 0%; 4 studies, 1000 participants; low-certainty evidence).  Gonadotropins with GnRH (gonadotropin-releasing hormone) agonist versus gonadotropins alone (4 studies) No data were available for live birth. The pooled effect of two studies  revealed that we are uncertain whether gonadotropins with GnRH agonist lead to a higher multiple pregnancy rate compared to gonadotropins alone (OR 2.53, 95% CI 0.82 to 7.86; I² = 0; 2 studies, 264 participants; very low-certainty evidence).  Gonadotropins with GnRH antagonist versus gonadotropins alone (14 studies) Three studies reported live birth rate per couple, and we are uncertain whether gonadotropins with GnRH antagonist improve live birth rate compared to gonadotropins (OR 1.5, 95% CI 0.52 to 4.39; I² = 81%; 3 studies, 419 participants; very low-certainty evidence). This suggests that if the chance of a live birth following gonadotropins alone is 25.7%, the chance following gonadotropins combined with GnRH antagonist would be between 15.2% and 60.3%. We are also uncertain whether gonadotropins combined with GnRH antagonist lead to a higher multiple pregnancy rate compared with gonadotropins alone (OR 1.30, 95% CI 0.74 to 2.28; I² = 0%; 10 studies, 2095 participants; moderate-certainty evidence). Gonadotropins with anti-oestrogens versus gonadotropins alone (2 studies) Neither of the studies reported data for live birth rate. We are uncertain whether gonadotropins combined with anti-oestrogens lead to a higher multiple pregnancy rate compared with gonadotropins alone, based on one study (OR 3.03, 95% CI 0.12 to 75.1; 1 study, 230 participants; low-certainty evidence). Aromatase inhibitors versus gonadotropins (6 studies) Two studies  revealed that aromatase inhibitors may decrease live birth rate compared with gonadotropins (OR 0.49, 95% CI 0.34 to 0.71; I²=0%; 2 studies, 651 participants; low-certainty evidence). This suggests that if the chance of a live birth following gonadotropins alone is 31.9%,  the chance of live birth following aromatase inhibitors would be between 13.7% and 25%. We are uncertain whether aromatase inhibitors compared with gonadotropins lead to a higher multiple pregnancy rate (OR 0.69, 95% CI 0.06 to 8.17; I²=77%; 3 studies, 731 participants; very low-certainty evidence).  Aromatase inhibitors with gonadotropins versus anti-oestrogens with gonadotropins (8 studies) We are uncertain whether aromatase inhibitors combined with gonadotropins improve live birth rate compared with anti-oestrogens plus gonadotropins (OR 0.99, 95% CI 0.3 8 to 2.54;  I² = 69%; 3 studies, 708 participants; very low-certainty evidence). This suggests that if the chance of a live birth following anti-oestrogens plus gonadotropins is 13.8%, the chance following aromatase inhibitors plus gonadotropins would be between 5.7% and 28.9%. We are uncertain of the effect of aromatase inhibitors combined with gonadotropins compared to anti-oestrogens combined with gonadotropins on multiple pregnancy rate (OR 1.31, 95% CI 0.39 to 4.37;  I² = 0%; 5 studies, 901 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

Based on the available results, gonadotropins probably improve cumulative live birth rate compared with anti-oestrogens (moderate-certainty evidence). Gonadotropins may also improve cumulative live birth rate when compared with aromatase inhibitors (low-certainty evidence). From the available data, there is no convincing evidence that aromatase inhibitors lead to higher live birth rates compared to anti-oestrogens. None of the agents compared lead to significantly higher multiple pregnancy rates. Based on low-certainty evidence, there does not seem to be a role for different combined therapies, nor for adding GnRH agonists or GnRH antagonists in IUI programs.

Evidence-based treatments for couples with unexplained infertility: a guideline

OBJECTIVE

To provide evidence-based recommendations to practicing physicians and others regarding the effectiveness and safety of therapies for unexplained infertility.

METHODS

ASRM conducted a literature search, which included systematic reviews, meta-analyses, randomized controlled trials, and prospective and retrospective comparative observational studies published from 1968 through 2019. The ASRM Practice Committee and a task force of experts used available evidence and informal consensus to develop evidence-based guideline recommendations.

MAIN OUTCOME MEASURE(S)

Outcomes of interest included: live-birth rate, clinical pregnancy rate, implantation rate, fertilization rate, multiple pregnancy rate, dose of treatment, rate of ovarian hyperstimulation, abortion rate, and ectopic pregnancy rate.

RESULT(S)

The literature search identified 88 relevant studies to inform the evidence base for this guideline.

RECOMMENDATION(S)

Evidence-based recommendations were developed for the following treatments for couples with unexplained infertility: natural cycle with intrauterine insemination (IUI); clomiphene citrate with intercourse; aromatase inhibitors with intercourse; gonadotropins with intercourse; clomiphene citrate with IUI; aromatase inhibitors with IUI; combination of clomiphene citrate or letrozole and gonadotropins (low dose and conventional dose) with IUI; low-dose gonadotropins with IUI; conventional-dose gonadotropins with IUI; timing of IUI; and in vitro fertilization and treatment paradigms.

CONCLUSION(S)

The treatment of unexplained infertility is by necessity empiric. For most couples, the best initial therapy is a course (typically 3 or 4 cycles) of ovarian stimulation with oral medications and intrauterine insemination (OS-IUI) followed by in vitro fertilization for those unsuccessful with OS-IUI treatments.

Prospective randomized trial comparing efficacy of letrozole step-up protocol with letrozole plus gonadotropins for controlled ovarian stimulation and intrauterine insemination in patients with unexplained infertility

PURPOSE

Empirical treatment options for unexplained infertility treatment include controlled ovarian stimulation (COS) with clomiphene citrate, letrozole or gonadotropins followed by intrauterine insemination (IUI). Achieving consistent multifollicular development with letrozole generally requires addition of gonadotropins. However, the cost and discomfort of injections remains a drawback of this regimen. Therefore, there is a need for evolving newer cost-effective regimens for COS/IUI using orally administered drugs like letrozole.

METHODS

Sixty couples with unexplained infertility (on standard infertility investigations) visiting the infertility clinic at a tertiary centre in North India were randomized into two groups. Group A COS was done by step-up protocol of letrozole from day 2 or 3 of menstrual cycle, starting with 2.5 mg and increased by 2.5 mg per day for next 3 days (2.5 mg, 5 mg, 7.5 mg, 10 mg). Group B COS was done with combination of letrozole and hMG (human menopausal gonadotropin). Starting from day 2 or 3 of menses, tablet letrozole 2.5 mg twice a day was given for 5 days. Intramuscular injection of hMG 150 IU was given every alternate day starting from day 7 and titrated according to the response. HCG was given when leading follicle was 17 mm and IUI done 36 h after HCG.

RESULTS

Twenty-eight couples in letrozole step-up group (group A) and 30 couples in letrozole plus hMG group (group B), completed follow up for 44 and 55 cycles, respectively. Mean numbers of follicle ≥ 16 mm in both groups were comparable: 1.74 (± 0.83) in group A and 1.94 (± 0.68) in group B (p = 0.178). Ovulation rate of 90.9% (40/44) was achieved in group A, whereas it was 100% (55/55) in group B (p = 0.022), although there was no significant difference in clinical pregnancy rate per patient, which was 3/28 (10.7%) in group A versus 5/30 (16.67%) in group B (p = 0.707). The mean (SD) cost of medicines was significantly lower in group A Rs. 345.00 (00) compared to group B Rs. 2148.64 (515.67) [p < 0.0001]. There was one case each of hyperstimulation and multiple pregnancies in group B, while none in group A.

CONCLUSION

It is possible to achieve multifollicular development with use of novel letrozole step-up protocol, even without addition of gonadotropins, at significantly lower cost.

Intrauterine Insemination: Fundamentals Revisited

Intrauterine insemination (IUI) is an assisted conception technique that involves the deposition of a processed semen sample in the upper uterine cavity, overcoming natural barriers to sperm ascent in the female reproductive tract. It is a cost-effective, noninvasive first-line therapy for selected patients with functionally normal tubes, and infertility due to a cervical factor, anovulation, moderate male factor, unexplained factors, immunological factor, and ejaculatory disorders with clinical pregnancy rates per cycle ranging from 10 to 20%. It, however, has limited use in patients with endometriosis, severe male factor infertility, tubal factor infertility, and advanced maternal age ≥ 35 years. IUI may be performed with or without ovarian stimulation. Controlled ovarian stimulation, particularly with low-dose gonadotropins, with IUI offers significant benefit in terms of pregnancy outcomes compared with natural cycle or timed intercourse, while reducing associated COH complications such as multiple pregnancies and ovarian hyperstimulation syndrome. Important prognostic indicators of success with IUI include age of patient, duration of infertility, stimulation protocol, infertility etiology, number of cycles, timing of insemination, number of preovulatory follicles on the day of hCG, processed total motile sperm > 10 million, and insemination count > 1 × 106 with > 4% normal spermatozoa. Alternative insemination techniques, such as Fallopian tube sperm perfusion, intracervical insemination, and intratubal insemination, provide no additional benefit compared to IUI. A complete couple workup that includes patient history, physical examination, and clinical and laboratory investigations is mandatory to justify the choice in favor of IUI and guide alternative patient management, while individualizing the treatment protocol according to the patient characteristics with a strict cancelation policy to limit multi-follicular development may help optimize IUI pregnancy outcomes.

Clomiphene citrate versus letrozole with gonadotropins in intrauterine insemination cycles: A randomized trial

BACKGROUND

Clomiphene citrate is one of the effective drugs for infertility treatment due to oligo-ovulation or anovulation. Intrauterine insemination (IUI) is one of more adherent methods for treatment of infertile cases which is followed by controlled ovarian hyperstimulation (COH).

OBJECTIVE

the aim of this study was to evaluate Clomiphene citrate versus letrozole with gonadotropins in IUI cycles.

MATERIALS AND METHODS

In this prospective randomized trial, 180 infertile women who were referred to Milad Hospital were selected. The first group received 5 mg/day letrozole on day 3-7 of menstrual cycle. The second group received 100 mg/day Clomiphene in the same way as letrozole. In both groups, human menopausal gonadotropin was administered every day starting on day between 6-8 of cycle. Ovulation was triggered with urinary Human Chorionic Gonadotropin (5000 IU) when have two follicles of ≥16 mm. IUI was performed 36 hr later.

RESULTS

The number of matured follicles, cycle cancellation, and abortion were the same in both groups. Endometrial thickness was higher at the time of human menopausal gonadotropin administration in letrozole group. Chemical and clinical pregnancy rates were much higher in letrozole group. Ovarian hyperstimulation was significantly higher in clomiphene group.

CONCLUSION

Letrozole appears to be a good alternative to clomiphene citrate with fewer side effects.

Comparison of letrozole versus tamoxifen effects in clomiphen citrate resistant women with polycystic ovarian syndrome

BACKGROUND

The objective of this prospective randomized study was to make a comparison between the effects of letrozole and tamoxifen (TMX) in ovulation induction in clomiphene (CC)-resistant women with polycystic ovarian syndrome (PCOS).

METHODS

The study comprised a total of 60 infertile women (180 cycles) with CCresistant PCOS selected from the clinics affiliated to the Department of Obstetrics and Gynecology of Tanta University. Patients were randomized to treatment with 2.5 mg of letrozole daily (30 patients, 90 cycles) or 20 mg of TMX daily (30 patients, 90 cycles) for 5 days from day 5 of menses and 10000 IU hCG when mature follicles become =18 mm in diameter. The chi-square and t-test were used for comparing two groups and p < 0.05 was considered significant.

RESULTS

The total number of follicles (=18 mm) in the letrozole group was more than TMX group. The endometrial thickness at the time of hCG administration was significantly higher (p < 0.05, at 95% CI) in the letrozole group than that of TMX group (10.2±0.7 vs. 9.1±0.2 mm). Ovulation occurred in 23.33% of cycles in the letrozole group and in 8.89% in the TMX group, whereas pregnancy occurred in 5.56% of the letrozole group and 2.22% of the TMX group.

CONCLUSION

Both letrozole and TMX should be considered as optional therapies for CC-resistant women. In addition, letrozole was superior to TMX in achieving a higher pregnancy and ovulation rate and also lesser side effects in comparison to tamoxifen.

A randomized trial comparing the ovulation induction efficacy of clomiphene citrate and letrozole

Background:

Letrazole is an aromatase inhibitor, which is useful in ovulation induction. However, evidence on its efficacy over clomiphene citrate, which is the first of drug used for therapy of anovulation, is insufficient in Indian patients.

Aims:

To compare the efficacy of letrozole and clomiphene citrate in attaining optimal follicular growth.

Materials and Methods:

The study was conducted in the infertility clinic of Mahatma Gandhi Medical College and Research Institute, Pondicherry, India from June 2008 to December 2009. Fifty women with ovulatory dysfunction as a cause of infertility were enrolled and randomized into two groups of 25 each. Group 1 received clomiphene citrate in incremental dose from 50 mg up to150 mg and Group 2 patient received letrozole in incremental dose from 2.5 mg to 7.5 mg, depending upon the ovulation response. In both the groups, number of follicles, diameter of large follicle, endometrial thickness, and serum estradiol and pregnancy rate were compared. The data from both groups are represented as mean and standard deviation and statistically compared using Student's t test.

Results:

The number of follicles (1.89 ± 0.9 vs 1.18 ± 0.393) and serum estradiol levels (437.5 ± 293.7 pg/mL vs 291.82 ± 59.86 pg/mL) were higher in Group 1, while follicular diameter (20.67 ± 0.970 mm vs. 20.76 ± 0.903 mm) and endometrial thickness (8.5 mm vs.7.4 mm) were similar in both the Groups.

Conclusions:

Although letrozole is used for ovulation induction in anovulatory infertility, no significant beneficial effects of letrozole compared to use of clomiphene citratewere observedin ourstudy. Hence, we concur with the use of clomiphene citrate as the first line of drug for ovulation induction in Indian population and warrant larger size studiesto further validate our results.

Sequential clomiphene citrate/hMG versus hMG for ovulation induction in clomiphene citrate-resistant women

OBJECTIVE

This study was designed to compare sequential clomiphene citrate/hMG regimen to hMG regimen for ovulation induction in clomiphene citrate-resistant women.

STUDY DESIGN

A comparative prospective study.

PATIENTS AND METHODS

Ninety infertile women were randomized to receive either sequential CC/hMG regimen (45 women) or low-dose step-up protocol of hMG (45 women). All participants had received at least six consecutive cycles of clomiphene citrate for ovulation induction within the last year before inclusion in this study, but they did not conceive. The CC/hMG regimen group received clomiphene citrate 100 mg/day for 5 days, followed by hMG 75 IU for 4 days. The hMG group received low-dose step-up protocol for 10-14 days. To detect the number and size of the follicles, TVS was done on cycle day 8 and repeated daily or every other day according to follicular development. When one to three follicles reached a diameter ≥18 mm, hCG injection was scheduled. Before hCG injection, the E2 level and endometrial thickness were evaluated. β-hCG levels were measured on cycle day 22.

RESULTS

There was no significant difference between the two studied groups regarding the demographic data, sperm parameters, and day 3 FSH, LH and estradiol. Also, there was no significant difference between the two studied groups regarding endometrial thickness, number of mature follicles, peak of E2 before hCG injection and number of cases that developed ovarian cyst or OHSS. The dose of gonadotropins used was significantly low in the CC/hMG group compared to the hMG group (295.2 ± 75.5 vs. 625.3 ± 65.0, respectively), and the pregnancy rate was significantly high in the CC/hMG group compared to the hMG group [12 (26.7 %) vs. 3 (6.7 %), respectively, p < 0.05].

CONCLUSION

The sequential CC/hMG regimen is as effective as hMG regimen for ovulation induction, produces satisfactory pregnancy results and reduces the treatment cost.

Comparing of letrozole versus clomiphene citrate combined with gonadotropins in intrauterine insemination cycles

BACKGROUND

Clomiphene citrate (CC) an agonist and antagonist of estrogen, is the first line treatment in ovarian stimulation. Anti-estrogenic effect of CC in endometrial thickness and cervical mucus has negative effect on pregnancy rate. Letrozole is an Aromatase Inhibitor has been seen that has acceptable pregnancy rate compared to CC.

OBJECTIVE

The aim of this study was to compare the efficacy of letrozole and clomiphene citrate (CC) with gonadotropins for ovarian stimulation in women candidate for intrauterine insemination (IUI).

MATERIALS AND METHODS

One hundred sixty patients eligible to IUI therapy enrolled in this study. Patients randomized to two groups: group A (received letrozole-gonadotropin) and group B (received CC-gonadotropin). In group A (n=80) letrozole was given on days 3-7 of the menstrual cycles. In group B clomiphen citrate was given like letrozole combined with human menopausal gonadotropin (hMG) administered every day starting on day 8. Ovulation was triggered with urinary HCG when the leading follicle (s) reached 18 mm in diameter. A single IUI was performed 36-40 hours later. The ovarian stimulation response (E2 levels and number of follicles, clinical pregnancy and endometrial thickness) was primary outcome.

RESULTS

Both groups were similar in demographic characteristics. There was a significantly lower peak serum E2 level in the letrozole group compared with CC. (236±86 Vs. 283±106 pg/mL, respectively; p<0.002). The number of mature (>18 mm) preovulatory follicles was significantly higher in CC group than letrozole group (2.2±.68 Vs. 2.02±0.63 respectively; p=0.025). Endometrial thickness measured at the time of hCG administration was significantly higher in letrozole group. (9.08±1.2 mm Vs. 8.1±1.9 mm; p=0.0001). The clinical pregnancy rate was comparable between two groups. Conclusion : Letrozole is a good and cost-effective alternative to CC in IUI cycles.

Hormonal, follicular and endometrial dynamics in letrozole-treated versus natural cycles in patients undergoing controlled ovarian stimulation

The objective of this study was to compare letrozole-stimulated cycles to natural cycles in 208 patients undergoing intrauterine insemination (IUI) between July of 2004 and January of 2007. Group I (n = 47) received cycle monitoring only (natural group), Group II (n = 125) received letrozole 2.5 mg/day on cycle days three to seven, and Group III (n = 36) received letrozole 5 mg/day on cycle days three to seven. There were no differences between the groups in endometrial thickness or P₄ on the day of hCG. Estradiol levels had higher variation in the second half of the follicular phase in both letrozole-treated groups compared to the control group. Estradiol per preovulatory follicle was similar in both letrozole cycles to that observed in the natural cycles. LH was lower on the day of hCG administration in the letrozole 2.5 mg/day group vs. the natural group. In summary, letrozole results in some minor changes in follicular, hormonal and endometrial dynamics compared to natural cycles. Increased folliculogenesis and pregnancy rates were observed in the letrozole-treated groups compared to the natural group. These findings need to be confirmed in larger, prospective studies.

Extended letrozole regimen versus clomiphene citrate for superovulation in patients with unexplained infertility undergoing intrauterine insemination: a randomized controlled trial

BACKGROUND

The aim of this randomized controlled trial was to compare the efficacy of extended letrozole regimen with clomiphene citrate in women with unexplained infertility undergoing superovulation and intrauterine insemination (IUI).

METHODS

Two hundred and fourteen patients with unexplained infertility were randomized into two equal groups using computer generated list and were treated by either letrozole 2.5 mg/day from cycle day 1 to 9 (extended letrozole group, 211 cycles) or clomiphene citrate 100 mg/day from cycle day 3 to 7 (clomiphene citrate group,210 cycles). Intrauterine insemination was performed 36 to 40 hours after HCG administration.

RESULTS

Both groups were comparable with regard to number of mature follicles (2.24 +/- 0.80 Vs 2.13 +/- 0.76) and the day of HCG administration. Serum estradiol was significantly greater in clomiphene citrate group (356 +/- 151 Vs 822 +/- 302 pg/ml, P = < 0.001) and the endometrial thickness was significantly greater in extended letrozole group (9.10 +/- 1.84 Vs 8.18 +/- 1.93 mm, P = < 0.001).The pregnancy rate per cycle and cumulative pregnancy rate were significantly greater in extended letrozole group (18.96% Vs 11.43% and 37.73% Vs 22.86%, respectively).

CONCLUSION

The extended letrozole regimen had a superior efficacy as compared with clomiphene citrate in patients of unexplained infertility undergoing superovulation and IUI.

TRIAL REGISTRATION

ClinicalTrials.gov, NCT01232075.

[Induction of ovulation]

To elaborate guidelines for the use of different treatment and different protocols for ovarian stimulation. SEARCHED STRATEGY: We searched for all publications which described randomised controlled trial evaluating different ovarian stimulation protocols and different indications on PubMed, Medline and Cochrane Database. The keywords were: ovulation induction, citrate of clomiphene, gonadotropin, metformin, anti estrogens, anti aromatase, pulsatile GnRH administration, cancer, ovarian hyperstimulation, thrombosis, multiple pregnancies, and complications. Randomised controlled trials were first considered. Then was considered recent meta analysis and cohort study. We mentioned when literature was weak.

Letrozole for ovulation induction and controlled ovarian hyperstimulation

PURPOSE OF REVIEW

Letrozole, an aromatase inhibitor, is the newest addition to our armamentarium in the treatment of infertility. It is utilized in much the same way as clomiphene citrate, but with some additional benefits. In this review, the latest studies will be summarized with emphasis on dose, duration of use, safety, number of mature follicles, and pregnancy outcomes.

RECENT FINDINGS

Letrozole has fewer side effects, and a shorter half-life than clomiphene citrate, and no demonstrable effect upon the receptivity of the endometrium. It is efficacious in treating women with chronic anovulation, unexplained infertility and diminished ovarian reserve. Its safety is superior to clomiphene citrate. Utilizing bio-equivalent doses, letrozole pregnancy rates are equal or superior to clomiphene citrate. Several studies suggest situations where it is more efficacious than gonadotropin treatment.

SUMMARY

With further study, this drug could replace clomiphene citrate as the primary medication for chronic anovulation and/or unexplained infertility. It could augment or even obviate the use of gonadotropins in the treatment of women who have been unsuccessful in achieving pregnancy with clomiphene citrate. It may also be an adjunct for women with diminished ovarian reserve. Further studies are needed to determine optimal dosing and long term safety for women treated with the drug.

Aromatase inhibitors for female infertility: a systematic review of the literature

Ovulation induction remains a milestone in the treatment of women with anovulatory infertility. Clomiphene citrate (CC) is considered the first line treatment for induction of ovulation in women with polycystic ovary syndrome (PCOS), while it may be used for ovulation induction in unexplained infertility. Aromatase inhibitors (AI) have been introduced as a new treatment option that could challenge CC for ovulation induction. A systematic review of the literature was conducted in order to highlight the efficacy and safety of AI in female infertility. Current data from randomized and non-randomized trials suggest that AI may have a role in ovulation induction regimens in PCOS patients, as well as for ovarian stimulation, since they achieve comparable clinical pregnancy rates to CC. Furthermore, when combined with gonadotrophins, AI improve the ovarian response of poor responders and reduce the gonadotrophin dose required. However, the current review is based on small trials with a limited number of patients. If solid data from future large adequately powered randomized trials support current evidence regarding efficacy and safety, AI might offer a new treatment choice for infertile women.

[Ovulation induction by means of letrozole]

BACKGROUND

Clomiphene citrate is a first line treatment of infertile anovulatory women. Although the treatment induces ovulation in most women, only one in four achieve uncomplicated pregnancy after treatment over several cycles. During recent years several clinics have started to use letrozole tablets for ovulation induction. This paper gives a short presentation of letrozole, mechanisms of action are explained, and pros and cons of letrozole versus clomiphene citrate are discussed.

MATERIAL AND METHODS

The paper is based on more than two years of clinical experience with use of letrozole for ovulation induction before timed sexual intercourse or intrauterine insemination and the use of letrozole during ovarian stimulation for in vitro fertilization. In addition, a non-systematic search in Pubmed has been performed to give an overview of what is known about letrozole for ovulation induction.

RESULTS

Use of letrozole is associated with a higher chance of uncomplicated pregnancy and a lower risk of multiple pregnancy than clomiphene citrate. In addition, more than 60 % of the women who are resistant to clomiphene citrate ovulate after treatment with letrozole. Letrozole combined with gonadotropin may also be beneficial in some women during in vitro fertilization.

INTERPRETATION

Studies of letrozole use in reproduction have so far been promising. However, large randomized studies are warranted before it can be concluded that letrozole should become a first line treatment for ovulation induction.

Comparison of letrozole with continuous gonadotropins and clomiphene-gonadotropin combination for ovulation induction in 1387 PCOS women after clomiphene citrate failure: a randomized prospective clinical trial

PURPOSE

Letrozole, though reported to be an effective ovulation inducing agent, warrants larger randomized trials. The purpose of this study is to compare the efficacy of letrozole with that of rFSH and clomiphene citrate(CC)/rFSH for ovarian stimulation in IUI cycles.

METHODS

Randomized, prospective, single-blinded clinical trial. 1387 PCOS women after CC failure were randomized into three groups: Group A received letrozole, Group B received CC with two doses rFSH and Group C received continuous rFSH day 2 onwards until hCG injection.

RESULTS

Group A, B and C had an ovulation rate of 79.30%, 56.95% and 89.89% and cycle cancellation rate of 20.70%, 43.05% and 10.11%, respectively. Pregnancy rates in Group A, B and C were 23.39%, 14.35% and 17.92%, while the miscarriage rates were 13.80%, 16.67% and 14.52%, respectively.

CONCLUSION

Letrozole appears to be a suitable ovulation inducing agent in PCOS women with CC failure and is found to be most effective when baseline estradiol level >60 pg/ml.