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

Assessment of Thyroid Auto-antibodies in Euthyroid Infertile Women with Polycystic Ovarian Syndrome - A Cross-sectional Analytical Study

Background

Thyroid auto-antibodies could be one of the many causes of infertility in women, especially with polycystic ovarian syndrome (PCOS) with a prevalence of 5%-15%. Patients with anti-thyroid antibodies have shown significantly lower fertilisation rates, implantation rates, lower pregnancy rates and increased risk of first-trimester abortions when compared with those without anti-thyroid antibodies.

Aim

The aim of the study was to assess the prevalence of thyroid auto-antibodies in euthyroid infertile women with PCOS and to compare the prevalence of thyroid autoantibodies in euthyroid infertile women with PCOS and without PCOS.

Settings and Design

This is a cross sectional analytical study involving 132 Infertile women with and without PCOS visiting the department of OBG in a tertiary care center. The study was conducted for period of 2 years.

Materials and Methods

A total of one hundred two women were enrolled in to the study. Sixty six women (66) had features of PCOS based on Rotterdam's criteria and 66 women were controls without PCOS features. Detailed history and examination were done for all women after taking informed and written consent. Previous hospital records were collected along with all biochemical investigations. The blood sample was collected for hormonal levels and thyroid auto-antibodies (anti-thyroid peroxidase [TPO] and anti-thyroglobulin [TG]) were assessed by enzyme-linked immunosorbent assay. The antibody levels were compared between the two groups along with the other parameters.

Statistical Analysis Used

Statistical tests were done using SPSS version 26. The Chi-square test or Fisher's exact test would be used to study the association of categorical data like the presence of hirsutism, acne, etc. The association of independent variables with outcome variables was assessed using Chi-square. The P < 0.05 was considered significant with a confidence interval of 95%.

Results

Anti-TPO antibody levels were found to be elevated in 25.4% of the PCOS group in comparison to only 3% of the non-PCOS group. Anti-TG antibodies of >100 U/mL were seen in 23 patients (34.3%) in PCOS group in comparison to two patients (3%) in non-PCOS group (P = 0.001). Both the antibodies (anti-TPO and anti-TG) were present in 21.2% of the PCOS group and 1.5% of the non-PCOS group.

Conclusion

Women with PCOS were found to be 11 times more likely to have anti-TPO antibodies and 20 times more likely to have anti-TG antibodies compared to non-PCOS women. This heightened prevalence of anti-thyroid antibodies suggests that testing for these antibodies may be warranted in women with PCOS, even if they have normal thyroid function. However, further studies with larger sample sizes are needed to validate these findings.

Extending letrozole treatment duration is effective in inducing ovulation in women with polycystic ovary syndrome and letrozole resistance

OBJECTIVE

To evaluate whether extending letrozole (LE) treatment duration could induce ovulation in women with polycystic ovary syndrome (PCOS) who previously failed to ovulate after a 5-day regimen of 5 mg LE daily for at least 1 ovulation induction cycle, defined as "LE resistance".

DESIGN

Retrospective cohort study.

SETTING

Tertiary care academic medical center.

PATIENT(S)

A total of 69 women with PCOS and LE resistance were included.

INTERVENTION(S)

The duration of LE treatment was increased in a stepwise manner (named as "2-step extended LE regimen"): a 7-day regimen of 5 mg LE daily was prescribed in the first ovulation induction cycle, and if ovulation did not occur, a 10-day regimen was prescribed in the subsequent cycle.

MAIN OUTCOME MEASURE(S)

Ovulation rate was the primary outcome. Clinical pregnancy rate, live birth rate, spontaneous ovulation rate, and ovarian hyperstimulation syndrome rate were the secondary outcomes.

RESULT(S)

Of the 69 patients, 48 ovulated after the 7-day and 16 after the 10-day regimen. Overall, the cumulative ovulation rate reached 92.75% (64/69) after the 2-step extended LE regimen, with a cumulative clinical pregnancy rate of 31.88% (22/69) and a cumulative live birth rate of 24.63% (17/69). All patients ovulated spontaneously without exogenous trigger agents and none experienced ovarian hyperstimulation syndrome.

CONCLUSION(S)

Extending LE treatment duration is a feasible method for inducing ovulation in women with PCOS and LE resistance.

Aromatase inhibitors (letrozole) for ovulation induction in infertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 5% to 20% of women worldwide and often leads to anovulatory infertility. Aromatase inhibitors (AIs) are a class of drugs that were introduced for ovulation induction in 2001. Since about 2001 clinical trials have reached differing conclusions as to whether the AI, letrozole, is at least as effective as the first-line treatment clomiphene citrate (CC), a selective oestrogen receptor modulator (SERM).

OBJECTIVES

To evaluate the effectiveness and safety of AIs (letrozole) (with or without adjuncts) compared to SERMs (with or without adjuncts) for infertile women with anovulatory PCOS for ovulation induction followed by timed intercourse or intrauterine insemination.

SEARCH METHODS

We searched the following sources, from their inception to 4 November 2021, to identify relevant randomised controlled trials (RCTs): the Cochrane Gynaecology and Fertility Group Specialised Register, CENTRAL, MEDLINE, Embase and PsycINFO. We also checked reference lists of relevant trials, searched the trial registers and contacted experts in the field for any additional trials. We did not restrict the searches by language or publication status.

SELECTION CRITERIA

We included all RCTs of AIs used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed risks of bias using RoB 1. We pooled trials where appropriate using a fixed-effect model to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes, and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth rate and OHSS rate. Secondary outcomes were clinical pregnancy, miscarriage and multiple pregnancy rates. We assessed the certainty of the evidence for each comparison using GRADE methods.

MAIN RESULTS

This is a substantive update of a previous review; of six previously included trials, we excluded four from this update and moved two to 'awaiting classification' due to concerns about validity of trial data. We included five additional trials for this update that now includes a total of 41 RCTs (6522 women). The AI, letrozole, was used in all trials. Letrozole compared to SERMs with or without adjuncts followed by timed intercourse Live birth rates were higher with letrozole (with or without adjuncts) compared to SERMs followed by timed intercourse (OR 1.72, 95% CI 1.40 to 2.11; I2 = 0%; number needed to treat for an additional beneficial outcome (NNTB) = 10; 11 trials, 2060 participants; high-certainty evidence). This suggests that in women with a 20% chance of live birth using SERMs, the live birth rate in women using letrozole with or without adjuncts would be 27% to 35%. There is high-certainty evidence that OHSS rates are similar with letrozole or SERMs (0.5% in both arms: risk difference (RD) -0.00, 95% CI -0.01 to 0.01; I2 = 0%; 10 trials, 1848 participants; high-certainty evidence). There is evidence for a higher pregnancy rate in favour of letrozole (OR 1.69, 95% CI 1.45 to 1.98; I2 = 0%; NNTB = 10; 23 trials, 3321 participants; high-certainty evidence). This suggests that in women with a 24% chance of clinical pregnancy using SERMs, the clinical pregnancy rate in women using letrozole with or without adjuncts would be 32% to 39%. There is little or no difference between treatment groups in the rate of miscarriage per pregnancy (25% with SERMs versus 24% with letrozole: OR 0.94, 95% CI 0.66 to 1.32; I2 = 0%; 15 trials, 736 participants; high-certainty evidence) and multiple pregnancy rate (2.2% with SERMs versus 1.6% with letrozole: OR 0.74, 95% CI 0.42 to 1.32; I2 = 0%; 14 trials, 2247 participants; high-certainty evidence). However, a funnel plot showed mild asymmetry, indicating that some trials in favour of SERMs might be missing.  Letrozole compared to laparoscopic ovarian drilling (LOD) One trial reported very low-certainty evidence that live birth rates may be higher with letrozole compared to LOD (OR 2.07, 95% CI 0.99 to 4.32; 1 trial, 141 participants; very low-certainty evidence). This suggests that in women with a 22% chance of live birth using LOD with or without adjuncts, the live birth rate in women using letrozole with or without adjuncts would be 24% to 47%. No trial reported OHSS rates. Due to the low-certainty evidence we are uncertain if letrozole improves pregnancy rates compared to LOD (OR 1.47, 95% CI 0.95 to 2.28; I² = 0%; 3 trials, 367 participants; low-certainty evidence). This suggests that in women with a 29% chance of clinical pregnancy using LOD with or without adjuncts, the clinical pregnancy rate in women using letrozole with or without adjuncts would be 28% to 45%. There seems to be no evidence of a difference in miscarriage rates per pregnancy comparing letrozole to LOD (OR 0.65, 95% CI 0.22 to 1.92; I² = 0%; 3 trials, 122 participants; low-certainty evidence). This also applies to multiple pregnancies (OR 3.00, 95% CI 0.12 to 74.90; 1 trial, 141 participants; very low-certainty evidence).

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth rates and pregnancy rates in infertile women with anovulatory PCOS, compared to SERMs, when used for ovulation induction, followed by intercourse. There is high-certainty evidence that OHSS rates are similar with letrozole or SERMs. There was high-certainty evidence of no difference in miscarriage rate and multiple pregnancy rate. We are uncertain if letrozole increases live birth rates compared to LOD. In this update, we added good quality trials and removed trials with concerns over data validity, thereby upgrading the certainty of the evidence base.

The impact of estradiol on pregnancy outcomes in letrozole-stimulated frozen embryo transfer cycles

OBJECTIVE

To assess the impact of low estradiol (E2) levels in letrozole-stimulated frozen embryo transfer (FET) cycles on pregnancy and neonatal outcomes.

DESIGN

Retrospective cohort.

SETTING

University-affiliated fertility center.

PATIENTS

All patients who underwent letrozole-stimulated FET cycles from January 2017 to April 2020 (n = 217). The "Low E2" group was defined as those with E2 serum levels on the day of trigger <10th percentile level (E2 <91.16 pg/mL, n = 22) and the "Normal E2" group was defined as those with E2 serum levels ≥10th percentile level (E2 ≥91.16 pg/mL, n = 195).

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Pregnancy outcomes including rates of clinical pregnancy, clinical miscarriage, and live birth. Neonatal outcomes including gestational age at delivery, birth weight, and Apgar score.

RESULTS

The mean ± SD estradiol level was 66.8 ± 14.8 pg/mL for the "Low E2" group compared with 366.3 ± 322.1 pg/mL for the "Normal E2" group. There were otherwise no substantial differences in cycle characteristics such as endometrial thickness on the day of ovulation trigger and progesterone levels in early pregnancy. The "Low E2" group had a significantly higher clinical miscarriage rate (36.4% vs. 8.8%, adjusted odds ratio 8.06) and lower live birth rate (31.8% vs. 57.9%, adjusted odds ratio 0.28). Neonatal outcomes such as gestational age at delivery, mean birth weight, Apgar scores, and incidence of newborn complications were not clinically different between the groups.

CONCLUSION

Low E2 levels were associated with a significantly higher miscarriage rate and lower live birth rate, suggesting that E2 levels in the follicular phase may have an effect on cycle outcomes. Given the rise in use of FET, further studies are needed to confirm our findings and understand the mechanisms.

The Effect of Prenatal Treatments on Offspring Events in the Presence of Competing Events: An Application to a Randomized Trial of Fertility Therapies

When studying the effect of a prenatal treatment on events in the offspring, failure to produce a live birth is a competing event for events in the offspring. A common approach to handle this competing event is reporting both the treatment-specific probabilities of live births and of the event of interest among live births. However, when the treatment affects the competing event, the latter probability cannot be interpreted as the causal effect among live births. Here we provide guidance for researchers interested in the effects of prenatal treatments on events in the offspring in the presence of the competing event "no live birth." We review the total effect of treatment on a composite event and the total effect of treatment on the event of interest. These causal effects are helpful for decision making but are agnostic about the pathways through which treatment affects the event of interest. Therefore, based on recent work, we also review three causal effects that explicitly consider the pathways through which treatment may affect the event of interest in the presence of competing events: the direct effect of treatment on the event of interest under an intervention to eliminate the competing event, the separable direct and indirect effects of treatment on the event of interest, and the effect of treatment in the principal stratum of those who would have had a live birth irrespective of treatment choice. As an illustrative example, we use a randomized trial of fertility treatments and risk of neonatal complications.

Letrozole and human menopausal gonadotropin for ovulation induction in clomiphene resistance polycystic ovary syndrome patients: A randomized controlled study

OBJECTIVE

To compare the effects of letrozole and human menopausal gonadotropin (HMG) in the treatment of patients with polycystic ovary syndrome (PCOS) resistant to clomiphene citrate (CC).

METHODS

A total of 96 clomiphene resistance polycystic ovary syndrome patients infertility were randomly divided into an LE group, and HMG group (n = 48). LE group orally received letrozole at 5.0 mg/d on the 3rd-5th days of menstrual cycle for 5 consecutive days, and 75 U/d HMG was given through intramuscular injection for 5 days starting from the third day of menstrual cycle in HMG group. Number of growing and mature follicles, serum E2 (pg/mL), serum P (ng/mL), endometrial thickness, occurrence of pregnancy and miscarriage were observed.

RESULTS

There was no significant difference in the number of ovulation cycles between the 2 groups (53.6% vs 64.7%, P > .05). The number of mature follicular cycles in the HMG group was higher than that of the letrozole group (P < .01). There were no significant differences in the clinical pregnancy rate (22.9% vs 27.1%, P > .05) and abortion rate (6.2% vs 10.4%, P > .05). There was no significant difference in the endometrial thickness between the 2 groups on the day of HCG injection [(9.1 ± 0.2) mm vs (10.7 ± 1.6) mm, P > .05]; the serum estradiol (E2) was lower in the letrozole group. The incidence of ovarian cysts was lower than that of HMG group (P < .05). There was2 ovarian hyperstimulation syndrome in the letrozole group; the incidence of ovarian hyperstimulation syndrome in the HMG group was 12.5%.

CONCLUSION

Letrozole-induced ovulation can obtain ovulation rate and pregnancy rate similar to gonadotropin, but reduce the risk associated with treatment. It can be used as an effective ovulation option for patients with polycystic ovary syndrome who are resistant to clomiphene.

Comparison of the pregnancy outcomes and the incidence of fetal congenital abnormalities in infertile women treated with letrozole and clomiphene citrate

OBJECTIVES

The aim of the study was to evaluate the incidence of congenital fetal anomalies reported among infertile Iranian women treated with letrozole compared to those treated with Clomiphene Citrate (CC).

METHODS

This retrospective case-control study was performed based on information available from infertile patients referred to the Akbar-Abadi Hospital IVF Center, Tehran, Iran, undergoing ovulation induction (OI) or intrauterine insemination (IUI) cycles from 2007 to 2014.We compared sonographic findings, fertility results, pregnancy complications and congenital anomalies in two groups of women treated with letrozole and CC.

RESULTS

Overall, the results of the 2009 cycles including 1237 CC cycles and 772 letrozole cycles were evaluated. In spite of a higher chance of ovulation following CC treatment, overall fertility rates were similar in the two treatment groups. The frequency of adverse outcomes of pregnancy was similar in the two groups, except for the incidence of first trimester abortion, which was significantly higher in the CC-treated group. The frequency of fetal anomalies and major chromosomal abnormalities in the Letrozole group was 4.76% (five cases), and in the CC group, it was 2.12% (three cases). This difference was not statistically significant.

CONCLUSION

Based on the findings of this study, it seems that the incidence of congenital anomalies in offspring after OI with letrozole is not increased compared to the CC group.

Aromatase inhibitors (letrozole) for subfertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a class of drugs that were introduced for ovulation induction in 2001. Since about 2001 clinical trials have reached differing conclusions as to whether the AI letrozole is at least as effective as the first-line treatment clomiphene citrate (CC).

OBJECTIVES

To evaluate the effectiveness and safety of aromatase inhibitors for subfertile women with anovulatory PCOS for ovulation induction followed by timed intercourse or intrauterine insemination (IUI).

SEARCH METHODS

We searched the following sources from inception to November 2017 to identify relevant randomised controlled trials (RCTs): the Cochrane Gynaecology and Fertility Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, Embase, PsycINFO, Pubmed, LILACS, Web of Knowledge, the World Health Organization (WHO) clinical trials register and Clinicaltrials.gov. We also searched the references of relevant articles. We did not restrict the searches by language or publication status.

SELECTION CRITERIA

We included all RCTs of AIs used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed risks of bias. We pooled studies where appropriate using a fixed-effect model to calculate odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes, and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth and OHSS. Secondary outcomes were clinical pregnancy, miscarriage and multiple pregnancy. We assessed the quality of the evidence for each comparison using GRADE methods.

MAIN RESULTS

This is a substantive update of a previous review. We identified 16 additional studies for the 2018 update. We include 42 RCTs (7935 women). The aromatase inhibitor letrozole was used in all studies.Letrozole compared to clomiphene citrate (CC) with or without adjuncts followed by timed intercourseLive birth rates were higher with letrozole (with or without adjuncts) compared to clomiphene citrate (with our without adjuncts) followed by timed intercourse (OR 1.68, 95% CI 1.42 to 1.99; 2954 participants; 13 studies; I² = 0%; number needed to treat for an additional beneficial outcome (NNTB) = 10; moderate-quality evidence). There is high-quality evidence that OHSS rates are similar with letrozole or clomiphene citrate (0.5% in both arms: risk difference (RD) -0.00, 95% CI -0.01 to 0.00; 2536 participants; 12 studies; I² = 0%; high-quality evidence). There is evidence for a higher pregnancy rate in favour of letrozole (OR 1.56, 95% CI 1.37 to 1.78; 4629 participants; 25 studies; I² = 1%; NNTB = 10; moderate-quality evidence). There is little or no difference between treatment groups in the rate of miscarriage by pregnancy (20% with CC versus 19% with letrozole; OR 0.94, 95% CI 0.70 to 1.26; 1210 participants; 18 studies; I² = 0%; high-quality evidence) and multiple pregnancy rate (1.7% with CC versus 1.3% with letrozole; OR 0.69, 95% CI 0.41 to 1.16; 3579 participants; 17 studies; I² = 0%; high-quality evidence). However, a funnel plot showed mild asymmetry, indicating that some studies in favour of clomiphene might be missing.Letrozole compared to laparoscopic ovarian drillingThere is low-quality evidence that live birth rates are similar with letrozole or laparoscopic ovarian drilling (OR 1.38, 95% CI 0.95 to 2.02; 548 participants; 3 studies; I² = 23%; low-quality evidence). There is insufficient evidence for a difference in OHSS rates (RD 0.00, 95% CI -0.01 to 0.01; 260 participants; 1 study; low-quality evidence). There is low-quality evidence that pregnancy rates are similar (OR 1.28, 95% CI 0.94 to 1.74; 774 participants; 5 studies; I² = 0%; moderate-quality evidence). There is insufficient evidence for a difference in miscarriage rate by pregnancy (OR 0.66, 95% CI 0.30 to 1.43; 240 participants; 5 studies; I² = 0%; moderate-quality evidence), or multiple pregnancies (OR 3.00, 95% CI 0.12 to 74.90; 548 participants; 3 studies; I² = 0%; low-quality evidence).Additional comparisons were made for Letrozole versus placebo, Selective oestrogen receptor modulators (SERMS) followed by intrauterine insemination (IUI), follicle stimulating hormone (FSH), Anastrozole, as well as dosage and administration protocols. There is insufficient evidence for a difference in either group of treatment due to a limited number of studies. Hence more research is necessary.

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth and pregnancy rates in subfertile women with anovulatory polycystic ovary syndrome, compared to clomiphene citrate. There is high-quality evidence that OHSS rates are similar with letrozole or clomiphene citrate. There is high-quality evidence of no difference in miscarriage rates or multiple pregnancy rates. There is low-quality evidence of no difference in live birth and pregnancy rates between letrozole and laparoscopic ovarian drilling, although there were few relevant studies. For the 2018 update, we added good-quality trials, upgrading the quality of the evidence.

Letrozole versus clomiphene citrate in polycystic ovary syndrome: a meta-analysis of randomized controlled trials

PURPOSE

Polycystic ovary syndrome (PCOS) is a common endocrine disturbance affecting women in the reproductive age group. The present study aimed to compare the effects of letrozole (LE) and clomiphene citrate (CC) for ovulation induction in women with PCOS.

METHODS

The PUBMED, Web of Science, and EMBASE databases were screened systematically for randomized controlled trials (RCTs) published from database inception to July 2017.

RESULTS

Eleven RCTs involving 2255 patients were included, and data were independently extracted and analyzed using 95% risk ratios (RRs) and confidence intervals (CIs) based on a random- or fixed-effect model (as appropriate). Meta-analyses of nine RCTs comparing LE and CC ovulation induction, followed by timed intercourse, indicated that the former significantly increased the ovulation rate (RR = 1.18; 95% CI 1.03-1.36, P = 0.01), pregnancy rate (RR = 1.34; 95% CI 1.09-1.64, P = 0.006), and live birth rate (RR = 1.55; 95% CI 1.28-1.88, P < 0.00001). However, LE and CC did not differ significantly in terms of the multiple pregnancy and abortion rates. Furthermore, LE for ovulation induction significantly improved the pregnancy rate after IUI.

CONCLUSION

LE is superior to CC for ovulation induction in patients with PCOS.

Cost effectiveness of letrozole and purified urinary FSH in treating women with clomiphene citrate-resistant polycystic ovarian syndrome: a randomized controlled trial

We aimed to compare the cost effectiveness of letrozole versus purified urinary follicle stimulating hormone (FSH) in treating patients with clomiphene citrate (CC)-resistant polycystic ovary syndrome (PCOS). This was a randomized trial conducted in Cairo University and Beni-Suef University Hospitals, Egypt. A cohort of 140 eligible women was randomized to receive either letrozole 2.5 mg twice daily for five days, or FSH using a graduated regimen starting with a dose of 75 IU. Treatment was repeated for three months if pregnancy did not occur. There were no significant differences between the two treatments in the cumulative clinical pregnancy rate (30% vs. 34%; p = 0.578), cumulative ovulation rate (47% vs. 57%; p = 0.236), miscarriage rate (9% vs. 4%, p > 0.999) or multiple pregnancy rate (0% and 8%, p = 0.491) but the FSH cycles were 4.8 times more expensive. Letrozole and FSH were both effective in treating women with CC-resistant PCOS but letrozole was more cost effective.Study registration number: NCT02304107.

Effects of Letrozole-HMG and Clomiphene-HMG on Incidence of Luteinized Unruptured Follicle Syndrome in Infertile Women Undergoing Induction Ovulation and Intrauterine Insemination: A Randomised Trial

Background:

Luteinized unruptured follicle (LUF) syndrome is considered a cause of ovulation failure and a subtle cause of infertility. Preovulatory injection of human chorionic gonadotropin (HCG) prevents or treats LUF syndrome, but it has also occurred after the induction of ovulation with clomiphene/HMG and HCG. This study was designed for evaluation and comparison of LUF incidence in eligible infertile women undergoing two stimulation protocols (clomiphene + HMG and letrozole + HMG) in addition to intrauterine insemination (IUI). Some related factors were compared between LUF and non-LUF cycles as secondary outcomes.

Methods:

The study was designed as a prospective randomized controlled trial. Patients were randomized using a table of random numbers into two equal protocol groups. For group A, (n = 90) clomiphene citrate was administrated orally in doses of 100 mg/day, and group B (n = 90) orally received letrozole 5 mg/day from day 3 to 7 of the menstrual cycle. Then HMG 75IU/day was administered intramuscularly in both groups on day 8 of the menstrual cycle and the dose was adjusted on the basis of ovarian response. The optimum size of preovulatory follicles for the injection of HCG (10,000 IU) was considered 18–23 mm. The number and size of preovulatory follicles were assessed by vaginal ultrasound 12 h before HCG (D0). Endometrial thickness was measured as well. IUI was performed on all patients 38–40 h after HCG. The second ultrasound examination was performed to observe the evidence of oocyte releasing at the time of IUI (D1). If the follicles were unruptured, a third sonography was performed on day 7 after HCG (D7) to observe LUF syndrome.

Results:

There was a significant difference between clomiphene-HMG and letrozole-HMG in LUF (p = 0.021) and pregnancy (p = 0.041). The complete LUF in letrozole-HMG was lower than the alternative group and the pregnancy rate was higher. The patients in the non-LUF group had higher midluteal progesterone and a thicker endometrium compared to LUF cycles (p = 0.039) and (p < 0.001). The results of our multivariate logistic regression indicate that size 18–19.9 mm leads to the complete LUF less than ≥22 mm [AOR: 0.25, P = 0.005], and in size 20– 21.9 mm as well [AOR: 0.17, P = 0.002].

Conclusion:

Letrozole, with lower incidences of LUF, is more effective than clomiphene citrate for the induction of ovulation in IUI cycles. In our study, we illustrated that larger follicles of ≥22 mm diameter were associated with higher incidences of LUF. We recommend that further studies investigate and focus on the relationship between follicular size and/or full hormonal profiles and LUF.

Minimal stimulation using gonadotropin combined with clomiphene citrate or letrozole for intrauterine insemination

PURPOSE

To evaluate the efficacy of minimal stimulation using discretely administered gonadotropin combined with clomiphene citrate (CC) or letrozole (LTZ) for intrauterine insemination (IUI) cycles.

MATERIALS AND METHODS

Total 257 IUI cycles from 158 infertile couples were assessed. A CC dose of 100 mg/day (n=126 cycles) or a LTZ dose of 5 mg/day (n=131 cycles) was administered on days 3-5 of the menstrual cycle for 5 days. Each group received human menopausal gonadotropin at a dose of 150 IU by two or three alternative day: CC combined with alternate-day regimen for 2 or 3 days (CC+300, n=37; CC+450, n=89) and LTZ combined with alternate-day regimen for 2 or 3 days (LTZ+300, n=36; LTZ+450, n=95).

RESULTS

The clinical pregnancy rate was comparable between the CC and LTZ groups (18.3% vs. 13.0%, p=0.243). The clinical pregnancy rate also showed no significant difference among the 4 groups (21.6% vs. 16.9% vs. 11.1% vs. 12.6%, p=0.507). The multiple pregnancy rate was significantly higher in LTZ compared to CC group (37.5% vs. 8.7%, p=0.028) and in the LTZ+450 compared to CC+450 group (50% vs. 13.3%, p=0.038). Overall, there were 15 cases of ovarian hyperstimulation syndrome (OHSS), with the prevalence being significantly lower in the LTZ compared to CC group (1.5% vs. 10.3%, p=0.003). OHSS was more prevalent in the CC+450 compared to the LTZ+450 group (12.4% vs. 1.1%, p=0.002).

CONCLUSION

Our findings suggest that minimal stimulation using two alternate-day gonadotropin with LTZ decreases the development of OHSS and multiple pregnancies, while maintaining comparable pregnancy rates in IUI cycles.

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.

Aromatase inhibitors for subfertile women with polycystic ovary syndrome

BACKGROUND

Polycystic ovary syndrome (PCOS) is the most common cause of infrequent periods (oligomenorrhoea) and absence of periods (amenorrhoea). It affects about 4% to 8% of women worldwide and often leads to anovulatory subfertility. Aromatase inhibitors (AIs) are a novel class of drugs that were introduced for ovulation induction in 2001. Over the last ten years clinical trials have reached differing conclusions as to whether the AI letrozole is at least as effective as the first-line treatment clomiphene citrate (CC).

OBJECTIVES

To evaluate the effectiveness and safety of aromatase inhibitors for subfertile women with anovulatory PCOS.

SEARCH METHODS

We searched the following sources from inception to 24/10/2013 to identify relevant randomised controlled trials (RCTs): the Menstrual Disorders and Subfertility Group Specialised Register, the Cochrane Central Register of Controlled Trials, MEDLINE, EMBASE, PsycINFO, Pubmed, LILACS, Web of Knowledge, the World Health Organisation (WHO) clinical trials register and Clinicaltrials.gov. Furthermore, we manually searched the references of relevant articles.The search was not restricted by language or publication status.

SELECTION CRITERIA

We included all RCTs of aromatase inhibitors used alone or with other medical therapies for ovulation induction in women of reproductive age with anovulatory PCOS.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected trials, extracted the data and assessed trial quality. Studies were pooled where appropriate using a fixed effect model to calculate pooled odds ratios (ORs) and 95% confidence intervals (CIs) for most outcomes and risk differences (RDs) for ovarian hyperstimulation syndrome (OHSS). The primary outcomes were live birth and OHSS. Secondary outcomes were pregnancy, miscarriage and multiple pregnancy. The quality of the evidence for each comparison was assessed using GRADE methods.

MAIN RESULTS

We included 26 RCTs (5560 women). In all studies the aromatase inhibitor was letrozole. Live birth (12 RCTs) One RCT compared letrozole with placebo in women who were clomiphene resistant and the results were inconclusive (OR 3.17, 95% CI 0.12 to 83.17, n=36)Nine RCTs compared letrozole with clomiphene citrate (with or without adjuncts) followed by timed intercourse. The birth rate was higher in the letrozole group (OR 1.63, 95% CI 1.31 to 2.03, n=1783, I²=3%)Two RCTs compared letrozole with laparoscopic ovarian drilling. There was no evidence of a difference between the groups in live birth rate (OR 1.19, 95% CI 0.76 to 1.86, n=407, I²=0%) OHSS (16 RCTs) There was no evidence of a difference in OHSS rates when letrozole was compared with placebo (one RCT, n=36), clomiphene citrate (with or without adjuncts) followed by timed intercourse (nine RCTs, n=2179), clomiphene citrate (with or without adjuncts) followed by intrauterine insemination (IUI) (two RCTs, n=1494), laparoscopic ovarian drilling (one RCT, n=260) or anastrozole (one RCT, n=220). Events were absent or very rare, and no study had more than 2 cases of OHSS. Clinical pregnancy (25 RCTs) One RCT compared letrozole versus placebo in women who were clomiphene resistant and the results were inconclusive (OR 3.17, 95% CI 0.12 to 83.17, n=36)Fourteen RCTs compared letrozole versus clomiphene citrate (with or without adjuncts) followed by timed intercourse. The pregnancy rate was higher in the letrozole group (OR 1.32, 95% CI 1.09 to 1.60, n=2066, I²=25%)Three RCTs compared letrozole versus clomiphene citrate (with or without adjuncts) followed by IUI. The pregnancy rate was higher in the letrozole group (OR 1.71, 95% CI 1.30 to 2.25, n=1597)Three RCTs compared letrozole versus laparoscopic ovarian drilling. There was no evidence of a difference in the clinical pregnancy rate (OR 1.14, 95% CI 0.80 to 1.65, n=553, I²=0%)Two RCTs compared letrozole versus anastrozole, one RCT compared a five day versus a 10 day administration protocol for letrozole and another RCT compared 5 mg of letrozole versus 7.5 mg of letrozole. There was no evidence of a difference in the clinical pregnancy rate in these comparisons.The quality of the evidence was rated as low for live birth and pregnancy outcomes. The reasons for downgrading the evidence were poor reporting of study methods, possible publication bias and the tendency for studies that reported live birth to report higher clinical pregnancy rates in the letrozole group than studies that failed to report live birth (suggesting that results might be somewhat less favourable to letrozole if all studies reported live birth).

AUTHORS' CONCLUSIONS

Letrozole appears to improve live birth and pregnancy rates in subfertile women with anovulatory PCOS, compared to clomiphene citrate. The quality of this evidence is low and findings should be regarded with some caution. There appears to be no difference in effectiveness between letrozole and laparoscopic ovarian drilling, though there were few relevant studies. OHSS was a very rare event, with no occurrences in most studies.

Efficacy of combined metformin-letrozole in comparison with bilateral ovarian drilling in clomiphene-resistant infertile women with polycystic ovarian syndrome

OBJECTIVES

To compare the hormonal-metabolic profiles and reproductive outcomes between women receiving metformin plus letrozole and women undergoing bilateral ovarian drilling in clomiphene citrate (CC)-resistant women with polycystic ovary syndrome (PCOS).

METHODS

In this randomized study, 146 patients were randomly allocated into group 1 (n = 73) who received metformin plus letrozole, and group 2 (n = 73) who underwent bilateral ovarian drilling. Comparison was done between the basal and after treatment biochemical values for each group, in addition reproductive outcomes after treatment were compared between both groups.

RESULTS

There was significant reduction in testosterone (p ≤ 0.001), fasting insulin (p ≤ 0.001), and fasting glucose/fasting insulin ratio (p = 0.029) in metformin plus letrozole group, while there was significant reduction in FSH, LH and LH/FSH ratio in bilateral drilling group (p ≤ 0.001, 0.001 and 0.001). No significant difference in cycle regularity (p = 0.82), ovulation (p = 0.24), pregnancy rate (p = 0.32) and abortion rate (p = 0.51) between both groups.

CONCLUSION

Both metformin plus letrozole and bilateral ovarian drilling are similarly effective as second-line strategies for the treatment of women with PCOS who do not conceive with CC.

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.

Comparison of the effectiveness of clomiphene citrate, tamoxifen and letrozole in ovulation induction in infertility due to isolated unovulation

BACKGROUND

Unovulation is the most common cause of infertility. The first line oral treatment has been clomiphene citrate. Another anti-estrogen used for ovulation induction is tamoxifen. Many unovulatory infertile women are resistance to anti-estrogens and need another treatment. Alternative treatments are aromatas inhibitors.

OBJECTIVE

This study was designed to compare the effectiveness of clomiphene, tamoxifen and letrozole in ovulation induction outcomes in isolated non PCOS unovulatory patients.

MATERIALS AND METHODS

150 unovulatory infertile women who had isolated non- polycystic ovarian syndrome (PCOS), randomized to 3 groups. Group A received clomiphene 50 mg to maximum 150 mg for 5 days, Group B received tamoxifen 10mg to maximum 30 mg for 5 days, Group C received letrozole 2.5 mg for 5 days, to maximum 7.5 mg until ovulation was induced. If ovulation failed to occur with 5 days treatments, drug continued for 7 days. Treatment has been stopped if they became pregnant or if patient didn't ovulate with maximum dose for 7 days (resistant to treatment) or failed to concept after six months despite ovulation (failure of treatment). Main outcome measures were: number of mature follicles, endometrial thickness, pregnancy rate, multiple pregnancy rate, live birth and miscarriage.

RESULTS

Overall ovulation rate was 60 (73.4%), this rate in group A was 39 (78%), in group B it was 24 (68%) and in group C was 37 (74%). Pregnancy rate in groups A, B and C were, 32 (64%), 20 (40%), and 25 (50%) respectively, and live birth rate was 22 (44%) in A, 17 (34%) in B and 21 (42%) in C. Miscarriage rate with clomiphene was 10 (20%) while this was 3 (6%) in tamoxifen and 4 (8%) in letrozole group (p=0.05). One twin pregnancy was occurred with clomiphene and one with tamoxifen, while all pregnancies with letrozole were singleton.

CONCLUSION

Because of higher pregnancy rate with clomiphene citrate than tamoxifen and letrozole, Clomiphene citrate is still the first-line therapy for ovulation induction. Surprisingly, pregnancies after tamoxifen and letrozole have lower miscarriage rate than clomiphene.

Clomiphene citrate or letrozole as first-line ovulation induction drug in infertile PCOS women: A prospective randomized trial

OBJECTIVE

To compare Letrozole (5 mg) and clomiphene citrate (100 mg) as first line ovulation induction drug in infertile PCOS women.

STUDY DESIGN

Prospective Randomised trial.

SETTING

A Tertiary level infertility centre.

PATIENTS

103 infertile PCOS women.

INTERVENTIONS

Treatment naïve infertile PCOS women were randomised to treatment with 5 mg letrozole (51 patients) or 100 mg clomiphene citrate (52 patients) daily starting day 2 to day 6 of menstrual cycle. Timed intercourse or Intra Uterine Insemination (IUI) was advised 24 to 36 hours after Human Chorionic Gonadotropin (HCG) injection.

MAIN OUTCOME MEASURES

Ovulation rate, mono or multi follicular rate, days to ovulation, endometrial thickness, serum progesterone, serum estrogen, pregnancy rate, miscarriage rate.

RESULTS

The mean age, Body Mass Index (BMI), duration of infertility in both Clomiphene Citrate (CC) and Letrozole groups were similar.Ovulation rate was 73.08% in letrozole group and 60.78% in CC, which was not statistically significant (P=0.398). There was no statistically significant difference between Endometrial thickness (CC 7.61 ±1.96, Let 7.65 ± 2.10), Sr E2 on day of HCG (CC 178.3 ± 94.15, Let 162.09 ± 73.24), Days to ovulation (CC 14.2 ± 3.41; Let 13.13 ± 2.99) and Sr P4 on D21 (CC 10.58 ± 6.65; Let 11.86 ± 6.51). Monofolliculo genesis (CC 54.84, Let 79.49 %, P=0.027) and Pregnancy rate (CC 7.84%, Let 21.56% P=0.0125) were statistically significantly higher in letrozole group.

CONCLUSION

Our study shows that letrozole has excellent pregnancy rates compared to clomiphene citrate. Letrozole should be considered at par with clomiphene citrate as first line drug for ovulation induction in infertile PCOS women.

A prospective randomized trial comparing the efficacy of Letrozole and Clomiphene citrate in induction of ovulation in polycystic ovarian syndrome

OBJECTIVES:

To compare the efficacy of letrozole and clomiphene citrate (CC) in patients of anovulatory polycystic ovarian syndrome (PCOS) with infertility.

MATERIALS AND METHODS:

This prospective randomized clinical trial included 204 patients of PCOS. 98 patients (294 cycles) received 2.5–5 mg of letrozole; 106 patients (318 cycles) received 50–100 mg of CC (both orally from Days 3–7 of menstrual cycle). The treatment continued for three cycles in both the groups. Main outcome measures: ovulation rate, endometrial thickness, and pregnancy rate. Statistical analysis was done using SPSS 13 software. P value less than 0.05 was considered significant.

RESULTS:

The mean number of dominant follicles in letrozole groups and CC groups was 1.86±0.26 and 1.92±0.17, respectively (P=0.126). Number of ovulatory cycle in letrozole group was 196 (66.6%) versus 216 (67.9%) in CC group (P=0.712). The mean mid-cycle endometrial thickness was 9.1±0.3 mm in letrozole group and 6.3±1.1 in CC group, which was statistically significant (P=0.014). The mean Estradiol [E2] level in clomiphene citrate group was significantly higher in CC group (364.2±71.4 pg/mL) than letrozole group (248.2± 42.2 pg/mL). 43 patients from the letrozole group (43.8%) and 28 patients from the CC group (26.4%) became pregnant.

CONCLUSION:

Letrozole and CC have comparable ovulation rate. The effect of letrozole showed a better endometrial response and pregnancy rate compared with CC.

Letrozole in a low-cost in vitro fertilization protocol in intracytoplasmic sperm injection cycles for male factor infertility: A randomized controlled trial

INTRODUCTION

Letrozole, a selective aromatase inhibitor, reduces the total dose of gonadotrophin required for inducing follicular maturation. We evaluated if incorporation of letrozole could be an effective alternative for low-cost in vitro fertilization (IVF) protocol particularly in intracytoplasmic sperm injection (ICSI) cycles where male factor infertility is the sole indication for IVF.

MATERIALS AND METHODS

It is a randomized controlled single-blind trial. 94 women with history of severe male factor infertility were selected. 42 women (study group) received letrozole, 5 mg daily from day 3-7 and recombinant FSH (rFSH) 75IU/day from day 5 continuously till hCG injection. 52 women (control group) underwent continuous stimulation by rFSH (150-225IU/day) from day 2. GnRH-antagonist (Inj. Orgalutran 0.25 ml sub-cutaneous) was started at maximum follicle size of 14 in both groups. Ovulation was triggered by 10,000IU of hCG followed by IVF-ET. Main outcome measures were total dose of rFSH (IU/cycle), terminal E2 (pg/ml), number of mature follicles, number of oocyte retrieved, transferable embryo, endometrial thickness, pregnancy rate and mean expenditure. Statistical analysis is done by using SPSS11.

RESULTS

As compared to control group (1756 ± 75IU), the study group i.e., Let-rFSH received (625 ± 98IU) significantly lower (P = 0.0001) total dose of rFSH. Terminal E2 was significantly lower (P = 0.0001) in study group than control (830 ± 36 vs. 1076 ± 41 pg/ml) with significant increment in endometrial thickness (P = 0.0008) in study group, (9.1 ± 0.32 vs. 8.7 ± 0.69) which maintained an improved pregnancy rate though nonsignificant. The risk of hyperstimulation had significantly (P = 0.01) reduced in study group than control (0 vs. 7).Treatment outcome in all other aspects including pregnancy rate were statistically comparable. Per cycle mean expenditure was reduced by 34% in study group than control.

CONCLUSION

Adjunctive use of letrozole may be an effective mean of low-cost IVF therapy.

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.

Chinese herbal medicine and clomiphene citrate for anovulation: a meta-analysis of randomized controlled trials

OBJECTIVES

The study objective was to investigate the efficacy of Chinese herbal medicine for improving standard infertility treatments.

DESIGN

A search of the literature between 2000 and 2006 was done in English and Chinese using the search terms anovulation, infertility, clomiphene citrate, Chinese herbal medicine, and randomized controlled trials. A review was done of 1009 studies with selection criteria including randomized controlled trials (RCTs) of Chinese herbal medicine combined with clomiphene citrate (CC) versus a control arm using CC alone with primary endpoints of changes in basal body temperatures, ovulation rates, endometrial lining, and pregnancy outcomes.

RESULTS

Fourteen (14) randomized studies representing 1316 patients met inclusion criteria. Four (4) studies (n = 315) reported 14% higher likelihood of biphasic basal body temperatures (risk ratios [RR] = 1.14; 95% confidence interval [CI], 1.00, 1.29). Six (6) studies (n = 604) reported a nonsignificant 18% increase in ovulation rates (RR = 1.18; 95% CI, 0.91, 1.52). Two studies (n = 138) reported subjects 78% more likely to have endometrial lining greater than 6 mm (RR = 1.78; 95% CI, 1.22, 2.60). Thirteen (13) studies (n = 1202) reported a 50% increase in pregnancy rates (RR = 1.50; 95% CI, 1.23, 1.84).

CONCLUSIONS

Chinese herbal medicine may increase the effectiveness of CC therapy. However, the RCTs are of poor methodological quality and small sample size, and the results require confirmation with rigorously controlled studies.

Report of the international symposium: polycystic ovary syndrome: first Latin-American consensus

During the last years, numerous consensuses have been held in different countries in order to review the data concerning diagnosis and treatment and their relationship with the ethnic origin, social status and lifestyle of women with Polycystic Ovary Syndrome (PCOS). This study describes the conclusions concerning diagnostic criteria and the appropriate treatment of women with PCOS reached during the International Symposium Polycystic Ovary Syndrome, First Latin-American Consensus held in Buenos Aires, Argentina on 4th and 5th May 2009 to be applied in South American.

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.

Letrozole versus laparoscopic ovarian diathermy for ovulation induction in clomiphene-resistant women with polycystic ovary syndrome: a randomized controlled trial

PURPOSE

To compare the effect of letrozole with laparoscopic ovarian diathermy (LOD) for ovulation induction in clomiphene citrate (CC) resistant women with polycystic ovary syndrome (PCOS).

METHODS

Two hundred and sixty anovulatory women with CC-resistant PCOS were selected in this randomized controlled trial. Group A (n = 128) received 2.5 mg letrozole daily for 5 days for up to six cycles. Group B (n = 132) underwent LOD with 6 months follow-up. Outcome measures were ovulation rate, midcycle endometrial thickness, pregnancy, miscarriage and live birth rates.

RESULTS

Ovulation occurred in 335/512 cycles (65.4%) in letrozole group and 364/525 cycles (69.3%) in LOD group without significant difference between both groups. Resumption of regular menstruation was similar in both treatment groups. A significant increase in midcycle endometrial thickness was observed in letrozole group (8.8 ± 1.1 mm vs. 7.9 ± 1.2 mm) (P < 0.05). Pregnancy rate was similar in both groups (15.6 vs. 17.5%). There were no statistical significant differences as regards miscarriage and live birth rates between both groups. No multiple pregnancy or ovarian hyperstimulation occurred in either group.

CONCLUSION

Letrozole and LOD are equally effective for inducing ovulation and achieving pregnancy in CC-resistant PCOS patients.

Comparative evaluation of pregnancy outcome in gonadotrophin-clomiphene combination vs clomiphene alone in polycystic ovarian syndrome and unexplained infertility-A prospective clinical trial

OBJECTIVES

A large prospective clinical trial was conducted to compare the efficacy of single dose uFSH and clomiphene citrate combination with clomiphene citrate alone for ovulation induction to improve the pregnancy rate.

MATERIALS AND METHODS

The study was a randomized, prospective clinical trial. Totally, 1527 infertile women (4381 cycles) with polycystic ovarian syndrome (PCOS) (n=911/2573 cycles) and unexplained infertility (n=616/1808 cycles) were randomized into two groups. Group A received single dose of uFSH on D(3) of menstrual cycle along with clomiphene. Group B received clomiphene only for ovulation induction. We compared the pregnancy rate and miscarriage rate between two groups.

RESULTS

Group A had a pregnancy rate of 17% compared to 8.3% of Group B which was significantly higher (P=0.0001). The miscarriage rate was 11% in Group A and 10% in Group B which was not significant (P=0.99). Pregnancy rates in PCOS women were 22% in Group A and 9.3% in Group B which shows significantly higher pregnancy rate (P=0.0001) in anovulatory infertility. But in unexplained infertility, there was no significant difference in pregnancy rate between Group A (11%) and Group B(6.3%). Miscarriage rates were 8.8% and 9.5% in Group A and Group B, respectively, in PCOS women and 14% and 13% in women with unexplained infertility.

CONCLUSION

Addition of single dose of uFSH improves pregnancy outcome particularly in anovulatory infertility (WHO II). Correction of unexplained infertility may need more than simple correction of possible subtle ovulatory effect.

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.