The effect of ethinyl estradiol on endometrial thickness and uterine volume during ovulation induction by clomiphene citrate

Endometrial thickness after ovarian stimulation with gonadotropin, clomiphene, or letrozole for unexplained infertility, and association with treatment outcomes

OBJECTIVE

To study the association of endometrial thickness (EMT) with live birth rates (LBR) in ovarian stimulation with intrauterine insemination (OS-IUI) treatments for unexplained infertility.

DESIGN

Prospective cohort analysis of the Reproductive Medicine Network's Assessment of Multiple Intrauterine Gestations from Ovarian Stimulation (AMIGOS) randomized controlled trial.

SETTING

Multicenter randomized controlled trial.

PATIENTS

A total of 868 couples with unexplained infertility (n=2,459 cycles).

INTERVENTIONS

OS-IUI treatment cycles (n = 2,459) as part of the AMIGOS clinical trial.

MAIN OUTCOME MEASURES

Live birth rates; unadjusted and adjusted risk ratios (RR) for live birth by EMT category, calculated using generalized estimating equations.

RESULTS

The overall mean EMT on day of human chorionic gonadotropin administration in cycles with a live birth was significantly greater than in those without. Compared to the referent EMT group of 9 to 12 mm, the unadjusted RR for live birth for the EMT groups of ≤5 and 6-8 were 0.48 and 0.92, respectively. The test for trend indicated evidence of decreasing LBR with decreasing EMT. After adjustment for ovarian stimulation medication, a linear trend was no longer supported. Stratified analyses revealed no differences in associations by treatment group.

CONCLUSIONS

In OS-IUI for unexplained infertility, higher LBR are observed with increasing EMT; however, EMT is not significantly associated with LBR when adjusted for OS treatment type. Appreciable LBR are seen at all EMT, even those of ≤5 mm, suggesting that OS-IUI cycles should not be canceled for thin endometrium.

CLINICAL TRIAL REGISTRATION NUMBER

NCT01044862.

Effects of clomiphene citrate plus estradiol or progesterone on endometrial ultrastructure: An RCT

Background

Pinopods concentrations in endometrial surface is a marker of implantation. Estradiol valerate (EV) was used to change the adverse effects of Clomiphene Citrate (CC) on the endometrium.

Objective

The goal was to assess whether there is a significant difference in the endometrial pinopods concentrations and other parameters after adding EV and progesterone to higher doses of CC.

Materials and Methods

In this prospective randomized clinical trial, a total of 30 women who did not respond to 100 mg of CC from February 2016 to June 2016 were evaluated. They were divided into three groups: group I) received 150 mg of CC alone, group II) CC with EV, and group III) CC plus progesterone. On day 21 of the menstrual cycle, endometrial biopsy, a blood sampling, and a scanning by electron microscopy were performed.

Results

On day 21 of the menstrual cycle, there was no significant difference in the pinopods concentrations (p = 0.641) and serum estrogen levels (p = 0.276) between groups. However, the Serum progesterone levels in group I was higher than the other two groups (p = 0.007) in the same day.

Conclusion

Since the addition of EV and progesterone to higher dosages of CC did not change the pinopods concentration and serum estrogen levels on day 21 of the menstrual cycle, and the serum progesterone levels was higher in CC alone group (i.e. group I) compared to other groups, it can be concluded that the anti-estrogenic effects of CC just appear on the endometrium and not on the plasma levels.

Spatiotemporal Mapping of the Contracting Gravid Uterus of the Rabbit Shows Contrary Changes With Increasing Gestation and Dosage With Oxytocin

Spontaneous and oxytocin induced contractile activity was quantified in the bicornuate uteri of pregnant rabbits maintained in situ, using data from two- and uni- dimensional video spatiotemporal maps (VSTM) of linear and area strain rate and compared statistically. Spontaneous contractions occurred over a range of frequencies between 0.1 and 10 cpm, in gravid animals at 18-21 and at 28 days of gestation, and propagated both radially and longitudinally over the uterine wall overlying each fetus. Patches of contractions were randomly distributed over the entire surface of the cornua and were pleomorphic in shape. No spatial coordination was evident between longitudinal and circular muscle layers nor temporal coordination that could indicate the activity of a localized pacemaker. The density and duration of contractions decreased, and their frequency increased with the length of gestation in the non-laboring uterus. Increasing intravenous doses of oxytocin had no effect on the mean frequencies, or the mean durations of contractions in rabbits of 18-21 days gestation, but caused frequencies to decrease and durations to increase in rabbits of 28 days gestation, from greater spatial and temporal clustering of individual contractions. This was accompanied by an increase in the distance of propagation, the mean size of the patches of contraction, the area of the largest patch of contraction and the overall density of patches. Together these results suggest that progressive smooth muscle hypertrophy and displacement with increasing gestation is accompanied by a decrease in smooth muscle connectivity causing an increase in wall compliance and that oxytocin restores connectivity and decreases compliance, promoting volumetric expulsion rather than direct propulsion of the fetus by peristalsis. The latter effects were reversed by the β2 adrenergic receptor agonist salbutamol thus reducing area of contraction, and the duration and distance of propagation.

Oral medications including clomiphene citrate or aromatase inhibitors with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilisation

BACKGROUND

Gonadotropins are the most commonly used medications for controlled ovarian stimulation in in vitro fertilisation (IVF). However, they are expensive and invasive, and are associated with the risk of ovarian hyperstimulation syndrome (OHSS). Recent calls for more patient-friendly regimens have led to growing interest in the use of clomiphene citrate (CC) and aromatase inhibitors with or without gonadotropins to reduce the burden of hormonal injections. It is currently unknown whether regimens using CC or aromatase inhibitors such as letrozole (Ltz) are as effective as gonadotropins alone.

OBJECTIVES

To determine the effectiveness and safety of regimens including oral induction medication (such as clomiphene citrate or letrozole) versus gonadotropin-only regimens for controlled ovarian stimulation in IVF or intracytoplasmic sperm injection (ICSI) treatment.

SEARCH METHODS

We searched the following databases: Cochrane Gynaecology and Fertility Group Specialised Register (searched January 2017), the Cochrane Central Register of Controlled Trials (CENTRAL CRSO), MEDLINE (1946 to January 2017), Embase (1980 to January 2017), and reference lists of relevant articles. We also searched trials registries ClinicalTrials.gov (clinicaltrials.gov/) and the World Health Organization International Clinical Trials Registry Platform (www.who.int/trialsearch/Default.aspx). We handsearched relevant conference proceedings.

SELECTION CRITERIA

We included randomized controlled trials (RCTs). The primary outcomes were live-birth rate (LBR) and OHSS.

DATA COLLECTION AND ANALYSIS

Three review authors independently assessed trial eligibility and risk of bias. We calculated risk ratios (RR) and Peto odds ratio (OR) with 95% confidence intervals (CIs) for dichotomous outcomes and mean differences (MD) for continuous outcomes. We analyzed the general population of women undergoing IVF treatment and (as a separate analysis) women identified as poor responders. We assessed the overall quality of the evidence using the GRADE approach.

MAIN RESULTS

We included 27 studies in the updated review. Most of the new trials in the updated review included poor responders and evaluated Ltz protocols. We could perform meta-analysis with data from 22 studies including a total of 3599 participants. The quality of the evidence for different comparisons ranged from low to moderate. The main limitations in the quality of the evidence were risk of bias associated with poor reporting of study methods, and imprecision.In the general population of women undergoing IVF, it is unclear whether CC or Ltz used with or without gonadotropins compared to use of gonadotropins along with gonadotropin-releasing hormone (GnRH) agonists or antagonists resulted in a difference in live birth (RR 0.92, 95% CI 0.66 to 1.27, 4 RCTs, n = 493, I2 = 0%, low-quality evidence) or clinical pregnancy rate (RR 1.00, 95% CI 0.86 to 1.16, 12 RCTs, n = 1998, I2 = 3%, moderate-quality evidence). This means that for a typical clinic with 23% LBR using a GnRH agonist regimen, switching to CC or Ltz protocols would be expected to result in LBRs between 15% and 30%. Clomiphene citrate or Ltz protocols were associated with a reduction in the incidence of OHSS (Peto OR 0.21, 95% CI 0.11 to 0.41, 5 RCTs, n = 1067, I2 = 0%, low-quality evidence). This means that for a typical clinic with 6% prevalence of OHSS associated with a GnRH regimen, switching to CC or Ltz protocols would be expected to reduce the incidence to between 0.5% and 2.5%. We found evidence of an increase in cycle cancellation rate with the CC protocol compared to gonadotropins in GnRH protocols (RR 1.87, 95% CI 1.43 to 2.45, 9 RCTs, n = 1784, I2 = 61%, low-quality evidence). There was moderate quality evidence of a decrease in the mean number of ampoules used,) and mean number of oocytes collected with CC with or without gonadotropins compared to the gonadotropins in GnRH agonist protocols, though data were too heterogeneous to pool.Similarly, in the poor-responder population, it is unclear whether there was any difference in rates of live birth (RR 1.16, 95% CI 0.49 to 2.79, 2 RCTs, n = 357, I2 = 38%, low-quality evidence) or clinical pregnancy (RR 0.85, 95% CI 0.64 to 1.12, 8 RCTs, n = 1462, I2 = 0%, low-quality evidence) following CC or Ltz with or without gonadotropin versus gonadotropin and GnRH protocol. This means that for a typical clinic with a 5% LBR in the poor responders using a GnRH protocol, switching to CC or Ltz protocols would be expected to yield LBRs between 2% to 14%. There was low quality evidence that the CC or Ltz protocols were associated with an increase in the cycle cancellation rate (RR 1.46, 95% CI 1.18 to 1.81, 10 RCTs, n = 1601, I2 = 64%) and moderate quality evidence of a decrease in the mean number of gonadotropin ampoules used and the mean number of oocytes collected, though data were too heterogeneous to pool. The adverse effects of these protocols were poorly reported. In addition, data on foetal abnormalities following use of CC or Ltz protocols are lacking.

AUTHORS' CONCLUSIONS

We found no conclusive evidence indicating that clomiphene citrate or letrozole with or without gonadotropins differed from gonadotropins in GnRH agonist or antagonist protocols with respect to their effects on live-birth or pregnancy rates, either in the general population of women undergoing IVF treatment or in women who were poor responders. Use of clomiphene or letrozole led to a reduction in the amount of gonadotropins required and the incidence of OHSS. However, use of clomiphene citrate or letrozole may be associated with a significant increase in the incidence of cycle cancellations, as well as reductions in the mean number of oocytes retrieved in both the general IVF population and the poor responders. Larger, high-quality randomized trials are needed to reach a firm conclusion before they are adopted into routine clinical practice.

Comparison of the Effect of Clomiphene- Estradiol Valerate vs Letrozole on Endometrial Thickness, Abortion and Pregnancy Rate in Infertile Women with Polycystic Ovarian Syndrome

INTRODUCTION

Clomiphene citrate is the first-line therapy for ovulation induction in Polycystic Ovarian Syndrome (PCOS). This drug binds and blocks estrogen receptors and thought to have an anti estrogenic effect on endometrium volume, thus may have adverse effect on fertility.

AIM

This study aimed to compare the effect of Clomiphene citrate plus Estradiol Valerate with Letrozole on endometrial thickness, abortion and pregnancy rate in infertile women with PCOS undergoing ovulation induction.

MATERIALS AND METHODS

This was a randomized double blind clinical trial study on 100 women with PCOS, with an endometrial thickness less than 7mm in spite of follicles greater than 18mm after administration of Clomiphene citrate 100mg/d from 3(th) to 7(th) day of menstruation. They were randomly divided in two groups. Group A received 100mg Clomiphene citrate from day 3 to day 7 of menstruation and 4 mg Estradiol Valerate after the 8(th) day of menstruation until 14(th) day. Group B treated by 5mg Letrozole from day 3 to 7 of menstruation with placebo from 8(th) to 14(th) day of menstruation. In both groups endometrial thickness was measured by transvaginal sonography in the 14(th) day of menstruation. Data were analysed using SPSS Ver.18.0.

RESULTS

The mean age was 30.34 years in group A and 29.62 years in group B (p=0.381). The number of infertility years in group A was 3.73 years and in group B was 3.85 years. There was no significant relationship statistically between the two groups in terms of mean age and infertility years (p=0.99). Endometrial thickness in group A was 7.26mm and in group B was 8.17 mm. Pregnancy rates in group A and group B was 32% and 16% respectively. There was significant relationship statistically between the two groups in terms of endometrial thickness and pregnancy rates (p=0.021 and p=0.05). There was no abortion in group A and 5 cases had abortion in group B, there was a significant relationship between the two groups statistically (p=0.028).

CONCLUSION

Letrozole increased endometrial thickness and pregnancy rate in infertile women, therefore its administration is recommended.

The luteal phase after ovarian stimulation

Evaluation of the luteal phase after ovarian stimulation presents several difficulties. Until today, it has not been proved that in cycles stimulated with clomiphene citrate/human menopausal gonadotrophins, luteal supplementation with progesterone significantly increases implantation rate. On the contrary, it is accepted that in cycles stimulated with GnRH agonists/gonadotrophins, support of the luteal phase is essential for the achievement of pregnancy. In GnRH antagonist cycles luteal supplementation, although widely practised, is not at present supported by randomized controlled trials. Finally, it appears that the combination of gonadotrophin stimulation with human chorionic gonadotrophin results in an inadequate luteal phase with or without the use of either agonists or antagonists.

Clomiphene citrate in combination with gonadotropins for controlled ovarian stimulation in women undergoing in vitro fertilization

BACKGROUND

Gonadotropins are the most commonly used medication for controlled ovarian stimulation in in vitro fertilization (IVF). However, they are expensive, invasive and are associated with risk of ovarian hyperstimulation syndrome (OHSS). With recent calls for patient friendly IVF, there has been an interest in the use of clomiphene citrate with or without gonadotropins to reduce the burden of injections. However, it is not known whether regimens using clomiphene are at least as effective as gonadotropins alone.

OBJECTIVES

To determine whether clomiphene citrate with gonadotropins (with or without mid-cycle antagonist) is more effective than gonadotropins with gonadotropin-releasing hormone (GnRH) agonists for controlled ovarian stimulation in IVF or intracytoplasmic sperm injection (ICSI) treatment.

SEARCH METHODS

Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched March 2012), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, first quarter), MEDLINE (1970 to March 2012), EMBASE (1985 to Mar 2012) and reference lists of articles. Relevant conference proceedings were handsearched.

SELECTION CRITERIA

Randomised controlled trials (RCT) were included. Live birth rate (LBR) per woman was the primary outcome.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed the eligibility and quality of trials

MAIN RESULTS

Fourteen studies were included in the review. Meta-analysis could be performed with the data of 12 included studies, with a total of 2536 participants. There was no evidence that clomiphene along with gonadotropins for IVF, with or without mid-cycle GnRH antagonist, differed from gonadotropins alone in GnRH agonist protocols in terms of live births (5 RCTs, 1079 women; OR 0.93, 95% CI 0.69 to1.24) or clinical pregnancy (11 RCTs, 1864 women; OR 1.07, 95% CI 0.85 to1.33). This means that for a typical clinic with 23% LBR using a GnRH agonist regimen, switching to clomiphene protocols would be expected to result in LBRs between 16% and 26%. There was a significant reduction in the incidence of OHSS (5 RCTs, 1559 women; OR 0.23, 95% CI 0.10 to 0.52). This means that for a typical clinic with 3.5% prevalence of OHSS using a GnRH agonist regimen, switching to clomiphene citrate protocols would be expected to reduce the incidence to between 0.8% and 1.8%. The trials included in this review were very old and outcomes such as live births, multiple pregnancy, OHSS and miscarriages have not been reported by most studies.

AUTHORS' CONCLUSIONS

There was no evidence to indicate that clomiphene with gonadotropins (with or without GnRH antagonist) differed significantly from gonadotropins in GnRH agonist protocols for women undergoing IVF treatment, in terms of live births or pregnancy rates. Meanwhile, use of clomiphene led to a reduction in the incidence of OHSS. However, these results were based on data from a small number of underpowered randomised trials with few participants. Hence there was insufficient evidence to recommend use of clomiphene citrate in routine IVF practice. Larger trials with adequate power are required.

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.

The effect of administering vaginal estrogen to clomiphene citrate stimulated cycles on endometrial thickness and pregnancy rates in unexplained infertility

OBJECTIVE

Clomiphene citrate (CC) has some negative effects on the endometrium. We aimed to determine the effect of vaginally administered local estrogen (LE) on endometrial thickness (ET) and pregnancy rates in CC stimulated cycles.

MATERIAL AND METHODS

This was a prospective randomized crossover study that took place in a university hospital. The patients had received CC due to unexplained infertility (UI). Two different treatment protocols were given sequentially as, either CC+LE or CC alone. Each protocol was planned for two cycles and there was a one-month wash-out period between protocols. The effects of LE on the 3(rd) and 9(th) day, the ovulation day (OD) and 7(th) postovulation day (POD7) were investigated.

RESULTS

A total of 6 pregnancies were achieved with 3 patients from each protocol. The ET was 7.6±1.4 mm and 8.3±2.1 mm respectively and significantly different in the CC group and the CC+E2 groups on the OD (p=.039), while these values were 9.7±2.3 mm and 10.9±3.0 mm respectively and significantly different on the POD7 (p=.007). There was no significant difference between the groups for arterial PI values on the OD and POD7. The frequency of thin endometrium (<6 mm) was 15.2% and 12.2% respectively in the CC group and the CC+E2 group on the OD (p=.628) and 5.1% and 1.2% respectively on the POD7 (p=.182).

CONCLUSION

Adding vaginal LE to CC stimulated cycles led to a significant increase in ET on the OD and POD7. However, this difference in thickness was not reflected in the pregnancy rates in this study.

Endometrial Receptivity and its Predictive Value for IVF/ICSI-Outcome

Endometrial receptivity plays a crucial role in the establishment of a healthy pregnancy in cycles of assisted reproduction. The endometrium as a key factor during reproduction can be assessed in multiple ways, most commonly through transvaginal grey-scale or 3-D ultrasound. It has been shown that controlled ovarian hyperstimulation has a great impact on the uterine lining, which leads to different study results for the predictive value of endometrial factors measured on different cycle days. There is no clear consensus on whether endometrial factors are appropriate to predict treatment outcome and if so, which one is suited best. The aim of this review is to summarize recent findings of studies about the influence of endometrial thickness, volume and pattern on IVF- and ICSI-treatment outcome and provide an overview of future developments in the field.

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.

Effects of α and β recombinant FSH (Gonal-F, Puregon) and progesterone upon human endometrial cell proliferation in-vitro: a preliminary study

Endometrial proliferation or regeneration during menstrual cycle is regulated by sexual hormones. However, the effect of gonadotrophins on the endometrial cell growth remains obscure. Herein, we aimed to investigate the effects of r-FSH (Gonal-F, Puregon) and progesterone on the proliferation of human endometrial cells in-vitro. According as gonadotrophin concentrations, the follicular-phase endometrial cells were divided into six groups: (1) 0 (controls), (2) 1; (3) 10; (4) 100; (5) 1000; (6) 100,000 μIU/ml. The cell countings with microscopy and cell proliferation kit assay were used to assess the endometrial cell proliferations. In Gonal-F groups, the cell absorptions (%) after 24/48 h culture were: (1) 100/100; (2) 103.8/102.3; (3) 104.8/102.8; (4) 102.3/101.3; (5) 96.3/94.2; (6) 86.8/84.3. In Puregon groups, the cell absorptions were: (1) 100/100; (2) 102.8/101.9; (3) 103/102.3; (4) 103.9/103.5; (5) 102.9/102.4; (6) 103.7/103.2 (non-different). In progesterone groups, the cell absorptions were: (1) 100/100; (2) 99.1/101.9; (3) 83.5/80.4; (4) 80.7/82.4. Higher dosage of Gonal-F (100,000 μIU/ml) and progesterone (10, 100 μg/ml) appeared the significant inhibition upon endometrium. We conclude that lower dosages of Gonal-F, Puregon, and progesterone appear the non-significant influence upon endometrium. Higher dosage of Gonal-F (10,000 μIU/ml) and progesterone (10, 100 μg/ml), but not Puregon, might interfere with the endometrial proliferation during follicular phase.

Stromal cell-specific apoptotic and antiestrogenic mechanisms may explain uterine defects in humans after clomiphene citrate therapy

OBJECTIVE

The purpose of this study was to investigate clomiphene citrate (CC)-induced modulation of uterine cell function in vivo.

STUDY DESIGN

Prepubertal female Sprague-Dawley rats were treated intraperitoneally with CC for 6 or 24 hours or with a combination of CC and/or 17-beta-estradiol (E2) for 4 days.

RESULTS

Chronic CC treatment induced apoptosis in a fraction of uterine stromal cells by activating the caspase-3-mediated apoptotic pathway. The damage was prevented by successive E2 treatment; however, pretreatment or concomitant treatment with E2 did not protect against CC-induced uterine apoptosis. CC decreased the protein expression of estrogen receptor alpha and increased its phosphorylation but did not affect estrogen receptor beta expression or phosphorylation. Furthermore, changes in Hoxa11, p27, and progesterone receptor protein levels and localization were associated with CC treatment.

CONCLUSION

We provide novel mechanistic insights into cellular and molecular events by which CC regulates uterine stromal cell function and hence the implantation process and pregnancy outcome.

Supplementation of clomiphene citrate cycles with Cimicifuga racemosa or ethinyl oestradiol--a randomized trial

The anti-oestrogenic activity of clomiphene citrate (CC) on the cervical mucous and endometrium may be the reason for the relatively low pregnancy rates in CC induction cycles. Various follicular-phase supplements have been tried to improve cycle outcome in these patients. This study compared follicular-phase supplementation with either phytoestrogen (PE) or ethinyl oestradiol (EE) in CC induction cycles for the treatment of unexplained infertility. A total of 134 patients were randomly allocated to each treatment group (67 each). The PE group needed significantly fewer days for adequate follicular maturation, had a thicker endometrium and higher oestradiol concentration at the time of human chorionic gonadotrophin injection (all P < 0.001). The PE group had higher luteal-phase serum progesterone compared with the EE group. No significant difference was found regarding clinical pregnancy rates (14.0% versus 21.1%, respectively). In conclusion, the cycle characteristics in unexplained infertility women treated with clomiphene citrate induction and timed intercourse improved after follicular-phase supplementation with PE compared with EE supplementation. Further studies are needed to confirm the mechanism beyond these effects.

Molecular mechanism of the inhibition of estradiol-induced endometrial epithelial cell proliferation by clomiphene citrate

We examined the molecular mechanisms of the antiestrogenic effects of clomiphene citrate (CC) in the endometrium using two types of cell lines, Ishikawa and EM-E6/E7/hTERT cells. CC or ICI182780 inhibited 17beta-estradiol (E2)-induced endometrial cell proliferation and transcriptional activation of the estrogen response element (ERE) gene. We directly visualized the ligand-estrogen receptor (ER)alpha interaction using green fluorescent protein (GFP)-tagged ER alpha in a single living cell. Whereas E2 changed the nuclear localization of GFP-ER alpha to a punctate distribution within 5 min, CC or ICI182780 changed the slower and less mobilization of GFP-ER alpha compared with E2. Pretreatment with CC or ICI182780 partly prevented the E2-induced nuclear redistribution of GFP-ER alpha. Fluorescence recovery after photobleaching revealed that GFP-ER alpha mobility treated with E2 was more rapid than that treated by CC or ICI182780. As coactivator recruitment to the ER is essential for ER-dependent transcription, we examined the interaction between ER alpha and steroid receptor coactivator-1 (SRC-1). The complex formation between ER alpha and SRC-1 was significantly increased by E2 but was prevented in the presence of CC or ICI182780 by coimmunoprecipitation. Moreover, the E2-induced colocalization of GFP-ER alpha and SRC-1 was prevented in the presence of CC or ICI182780 according to an immunofluorescence assay. We also observed that the reduction of SRC-1 using small interfering RNA for SRC-1 resulted in the inhibition of E2-induced cell proliferation and transcriptional activation of the ERE gene. Collectively, these results suggest that CC may inhibit E2-induced endometrial epithelial cell proliferation and ERE transactivation by inhibiting the recruitment of SRC-1 to ER alpha.

Clomiphene citrate or anastrozole for ovulation induction in women with polycystic ovary syndrome? A prospective controlled trial

OBJECTIVE

To compare the effects of anastrozole (1 mg) and clomiphene citrate (CC; 100 mg) used for ovulation induction in women with polycystic ovary syndrome.

DESIGN

Prospective controlled trial.

SETTING

University teaching hospital and private-practice setting.

PATIENT(S)

The study comprised a total of 216 infertile women (469 cycles) with polycystic ovary syndrome.

INTERVENTION(S)

Patients received anastrozole (1 mg/d; 115 patients, 243 cycles) for 5 days, starting on day 3 of menses. A matched historical group of patients with polycystic ovary syndrome who were treated with CC (100 mg/d; 101 patients, 226 cycles) was used as a control group. Timed intercourse was advised 24-36 hours after hCG injection.

MAIN OUTCOME MEASURE(S)

Number of follicles, serum E(2), serum P, endometrial thickness, and pregnancy and miscarriage rates.

RESULT(S)

The mean age, parity, and duration of infertility in both groups were similar, but statistically significantly more polycystic ovaries were found in the anastrozole group (odds ratio = 2.44; 95% confidence interval = 1.19-5.02). The total numbers of follicles were significantly higher in the CC group (3.8 +/- 0.6 vs. 3.4 +/- 0.5). Endometrial thickness at the time of hCG administration was significantly greater in the anastrozole group (10.1 +/- 0.22 mm vs. 8.2 +/- 0.69 mm). The duration of stimulation was similar in the two groups. Ovulation occurred in 165 (67.9%) of 243 cycles in the anastrozole group and in 150 (68.6%) of 226 cycles in the CC group without significant difference. Serum P was significantly higher in the CC group (7.1 +/- 1.11 vs. 8.1 +/- 0.88 ng/mL). The pregnancy and miscarriage rates were similar in the two groups.

CONCLUSION(S)

Anastrozole was associated with significantly fewer mature and growing follicles, thicker endometrium, and slightly higher pregnancy rate. Anastrozole may be helpful in situations in which multiple pregnancy is not desirable or the risk of ovarian hyperstimulation syndrome is high.

Strategies to reduce multiple pregnancies due to ovulation stimulation

OBJECTIVE

To review factors associated with high-order multiple births (HOMB) due to ovulation induction (OI) and the efficacy of strategies to reduce their occurrence.

DESIGN

Retrospective analysis of published studies of OI with intrauterine insemination (IUI) where patient and cycle characteristics were fully documented.

RESULT(S)

High-order multiple pregnancies (HOMP) were positively related to use of high doses of gonadotropin, number of 7-10 mm preovulatory follicles, and E(2), and inversely related to age and number of treatment cycles. Strategies successful in reducing HOMP include: use of clomiphene (CC) before gonadotropins, minimal gonadotropin doses, cancellation for more than three follicles >10-15 mm, and aspiration of excess follicles. Depending on the strategy used, 5%-20% of cycles may be canceled but HOMP rates can be less than 2% and pregnancy rates can average 10%-20% per cycle. Pregnancy rates per patient need not be reduced if low doses are continued for 4-6 cycles.

CONCLUSION(S)

High-order multiple pregnancies due to OI can be reduced to 2% or less by less aggressive stimulation without reducing overall chances of pregnancy for most patients.

Adding phytoestrogens to clomiphene induction in unexplained infertility patients--a randomized trial

This study investigated the role of oral phytoestrogens in improving pregnancy rate and cycle outcomes with clomiphene citrate. Patients with unexplained infertility and recurrent clomiphene citrate induction failure, were randomly divided into two groups: group I (n = 60) and group II (n = 59). Both groups received clomiphene citrate 150 mg per day (days 3 to 7). Group I received additional oral phytoestrogen (Cimicifuga racemosa) 120 mg/day from days 1 to 12. Human chorionic gonadotrophin (HCG) injection (10,000 IU i.m.) was given and timed intercourse was recommended when a leading follicle reached >17 mm and serum oestradiol exceeded 200 (pg/ml). There was a non-significant shortening of induction cycles in group I. Oestradiol and LH concentrations were higher in group I compared with group II. Endometrial thickness, serum progesterone and clinical pregnancy rate were significantly higher in group I (8.9 +/- 1.4 mm versus 7.5 +/- 1.3 mm, P < 0.001; 13.3 +/- 3.1 ng/ml versus 9.3 +/- 2.0 ng/ml, P < 0.01; 36.7% versus 13.6%, P < 0.01, respectively). It is concluded that adding C. racemosa rhizome dry extract to clomiphene citrate induction can improve the pregnancy rate and cycle outcomes in these couples.

Endometrial effects of letrozole and clomiphene citrate in women with polycystic ovary syndrome using spiral artery Doppler

OBJECTIVES

To compare the effects of letrozole and clomiphene citrate (CC) on endometrial response in PCOS using subendometrial spiral artery Doppler.

METHODS

Fifty consecutive patients of anovulatory PCOS were recruited. Twenty-five patients (58 cycles) received 2.5-5 mg of letrozole; 25 patients (56 cycles) received 50-100 mg of CC (both orally on days 5-9 of menses).

MAIN OUTCOME MEASURES

number of dominant follicles, endometrial thickness (ET), spiral artery resistance index (RI) and pulsatility index (PI) and pregnancy rate.

RESULTS

The mean number of dominant follicles in letrozole group and CC groups was 1.63+/-1.02 and 1.62+/-0.96, respectively (P>0.05). The mean mid cycle ET was 6.9+/-0.74 mm in letrozole group and 5.9+/-0.53 mm in CC group (P<0.05). In letrozole and CC groups, the mean RI of spiral artery were 0.63+/-0.05 and 0.79+/-0.09, respectively, and the mean PI of spiral artery were 1.19+/-0.06 and 1.55+/-0.13, respectively. Both RI and PI in the letrozole group showed significant lower impedance compared to CC group (P<0.05). Pregnancy rate per cycle was 19% (11/58) in the letrozole group and 12.5% (7/56) in the CC group (P>0.05).

CONCLUSION

The effect of letrozole showed a significantly better endometrial response compared to CC.

Defining the proliferative phase endometrial defect

OBJECTIVE

To evaluate proliferative phase endometrial development in a heterogeneous infertility population.

DESIGN

Retrospective study.

SETTING

University-based infertility practice.

PATIENT(S)

Two hundred forty-six treatment cycles.

INTERVENTION(S)

Clomiphene citrate or FSH ovarian stimulation, followed by IUI or IVF.

MAIN OUTCOME MEASURE(S)

Endometrial thickness according to transvaginal ultrasonography; clinical pregnancy rate.

RESULT(S)

Endometrial growth began from a nadir of approximately 4.5 mm on cycle day 4 and increased linearly to a plateau of approximately 10 mm on cycle day 9. This same pattern was observed in all cycles, regardless of pregnancy, drug, or underlying diagnosis. Follicle-stimulating hormone-stimulated cycles showed a significantly increased endometrial thickness compared with clomiphene citrate cycles (10.1 vs. 8.3 mm). Maximum endometrial thickness achieved showed a correlation with age, body mass index, and maximum E(2) level. Subjects who carried a primary diagnosis of polycystic ovary syndrome, endometriosis, or recurrent pregnancy loss all achieved a significantly lower peak endometrial thickness than control subjects. There was a trend toward increased endometrial thickness in cycles resulting in pregnancy compared with those not (10.1 vs. 9.6 mm, respectively).

CONCLUSION(S)

Endometrial development follows a predictable pattern, with a plateau in growth at cycle day 9. Diseases associated with infertility manifest a proliferative phase defect that can be recognized clinically.

RETRACTED: Clomiphene citrate or letrozole for ovulation induction in women with polycystic ovarian syndrome: a prospective randomized trial

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the ASRM Publications Committee Several reports of randomized clinical trials were recently the subject of an investigation conducted by the publications committee of the ASRM. The committee reviewed concerns related to the validity of data reported in those reports. The committee noted significant duplication of data reported in this manuscript with data reported in another journal (PMID 17364286; https://doi.org/10.1080/00016340601090337) and another publication in Fertility and Sterility (PMID: 18692823; https://doi.org/10.1016/j.fertnstert.2008.06.013) pertaining to different study groups that could not be explained. As we cannot vouch for the validity of the data, we have issued a retraction of this paper.

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

BACKGROUND

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

MATERIALS AND METHODS

Thirty-three infertile patients, aged 25-41 years, were enrolled. Patients received either anastrozole 1 mg daily (AI group) or clomiphene citrate 100 mg daily (CC group) from cycle day 3 to day 7. Number of mature follicles (> or =18 mm), endometrial thickness, pregnancy rate and serial hormone profiles (follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol (E(2)), testosterone and progesterone) were measured on cycle day 3, day 8, day 10, the day of intrauterine insemination (IUI), day 7 after IUI and day 14 after IUI.

RESULTS

Baseline parameters were similar in the two groups, including age, body mass index, infertility duration and day-3 serum hormones except FSH. The mean FSH value on day 3 was significantly different (4.3 mIU/ml in the AI group vs. 6.3 mIU/ml in the CC group; p < 0.05). The women receiving anastrozole had fewer ovulatory follicles (1.2 in the AI group vs. 1.8 in the CC group; p < 0.05) and a thicker endometrium (10.6 mm in the AI group vs. 7.8 mm in the CC group; p < 0.05). The levels of progesterone and testosterone were similar during ovulation stimulation cycles in both groups. On the other hand, the AI group had a significantly higher LH level but a significantly lower E(2) level in the stimulation cycle.

CONCLUSION

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

A new era in ovulation induction

OBJECTIVE

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

DESIGN

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

RESULT(S)

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

CONCLUSION(S)

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

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

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

Estradiol protects clomiphene citrate–induced apoptosis in ovarian follicular cells and ovulated cumulus–oocyte complexes

OBJECTIVE

To determine whether clomiphene citrate (CC) reduces E(2) level in the ovary and circulation and induces apoptosis in ovarian follicular cells and ovulated cumulus-oocyte complexes (COCs). If yes, to determine whether E(2) coadministration could protect against these adverse effects of CC.

DESIGN

A controlled prospective study.

SETTING

Laboratory research setting.

ANIMAL(S)

Ninety sexually immature female rats that were 24-25 days of age.

INTERVENTION(S)

The immature female rats were injected with a single dose of 10 IU of pregnant mare serum gonadotropin. After 48 hours, 10 IU of hCG along with 10 mg of CC per kilogram of body weight, with or without 2.0 mg of E2 per kilogram of body weight were coadministered. After 16 hrs, the rats were killed; COCs were collected from oviduct and ovaries were isolated.

MAIN OUTCOME MEASURE(S)

Number of superovulated COCs, oocyte morphology, E2 level in ovary and serum, histology of ovary, DNA fragmentation, and bax protein expression in ovary and COCs.

RESULT(S)

The number of COCs and E2 level in ovary and serum were reduced, whereas membrane blebbing in oocytes, bax protein expression, and DNA fragmentation in ovarian follicular cells and ovulated COCs were induced after CC treatment. These adverse effects of CC were protected against if animals were coadministered with E2.

CONCLUSION(S)

Clomiphene citrate-induced apoptosis in ovarian follicular cells (probably granulosa cells), thereby reducing E2 level in ovary and circulation that might have resulted in poor development and maturation of oocytes leading to reduced ovulation.

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

OBJECTIVE

To compare the effects of the aromatase inhibitor letrozole (7.5 mg) and clomiphene citrate (CC; 100 mg) in women undergoing superovulation and IUI.

DESIGN

Prospective randomized trial.

SETTING

University teaching hospital.

PATIENT(S)

We studied a total of 238 cycles of superovulation and IUI in women with idiopathic infertility.

INTERVENTIONS

Patients were randomized into treatment with 7.5 mg of letrozole daily (74 patients, 115 cycles) or 100 mg of CC daily (80 patients, 123 cycles).

MAIN OUTCOME MEASURE(S)

Number of follicles, endometrial thickness, pregnancy rate, and miscarriage rate.

RESULT(S)

The mean age, parity, and duration of infertility in both groups of patients were similar. There was no significant difference between the total number of developing follicles in the letrozole (5.7 +/- 3.7) and in the CC groups (4.8 +/- 2.5). The number of follicles of > or =14 mm and of >18 mm were 2.1 +/- 1.2 and 1.4 +/- 0.7 in the letrozole group, and 1.7 +/- 0.9 and 1.1 +/- 0.5 in the CC group, respectively. No difference was found in the endometrial thickness between the two groups (7.1 +/- 0.2 mm in the letrozole group, 8.2 +/- 5.9 mm in the CC group). The pregnancy rate per cycle was 11.5% in the letrozole group and 8.9% in the CC group. Four of the 11 pregnancies in the CC group resulted in a miscarriage (36.6%).

CONCLUSION(S)

Superovulation and IUI with letrozole and CC are associated with similar pregnancy rates, but the miscarriage rate is higher with CC. The ideal dose of letrozole remains unknown and further study is needed.

Is ovulation induction still a therapeutic problem in patients with polycystic ovary syndrome?

Polycystic ovary syndrome (PCOS) is one of the most common endocrine diseases affecting women of fertile age, and is characterized by hyperandrogenism, chronic anovulatory cycles and oligomenorrhea or amenorrhea. Given the repercussions of chronic anovulation on sterility, PCOS is a heavy social burden. Here we describe the procedures used to induce ovulation in PCOS patients, the surgical approach and medical treatments that are still being experimented.

Effect of repeated administration of clomiphene citrate at two different times on the endometrium in patients undergoing intrauterine insemination

Background, Aims and Methods:  Clomiphene citrate (CC) has been widely used for induction of ovulation; however, despite the high rate of ovulation, the pregnancy rate is only 30%. The anti-estrogenic effect of CC on the endometrium is one explanation for this finding. It is well known that repeated administration of CC enhances its anti-estrogenic effect. To overcome this adverse affect, a number of techniques have been used. One technique is the early administration of CC, in an attempt to decrease the anti-estrogenic effects of CC on the endometrium. The aim of the present study was to retrospectively evaluate if repeated administration of CC at varying times may affect the endometrium during preovulatory period; pregnancy rates were compiled for patients with unexplained infertility undergoing intrauterine insemination (IUI). The patients were divided into four groups based on the number of repeat administrations and the time of CC administration. Results:  The endometrial thickness at the day of human chorionic gonadotropin administration was greater in early administration within three consecutive CC cycles than the others. Conclusion:  When the endometrium is thin during classical administration of CC, it is worth attempting the early administration of CC in the CC/IUI treatment for patients with unexplained infertility. However, this effect disappeared over the duration of the three consecutive CC cycles. (Reprod Med Biol 2004; 3: 153-157).

Aromatase inhibitors for the treatment of infertility

Ovarian stimulation during infertility treatment is used either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antioestrogen, clomiphene citrate and injectable gonadotrophins. In spite of the high ovulation rate, the use of clomiphene citrate is associated with adverse side effects and low pregnancy rates. In clomiphene citrate failures, gonadotrophin injections are generally the next treatment option but, especially in polycystic ovarian syndrome, are associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of ovarian hyperstimulation syndrome and with minimal monitoring is preferred. It was hypothesised that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus and/or pituitary from oestrogen negative feedback. The success of aromatase inhibitors in induction and augmentation of ovulation has been reported. In addition, increased intraovarian androgen levels may synergise with central effects of decreased oestrogen to enhance ovarian response to gonadotrophin stimulation. This increased sensitivity to follicle-stimulating hormone may be especially useful in poor responders. The potential future applications for aromatase inhibitors in infertility management are also discussed.

Regulation of HOXA-10 expression by testosterone in vitro and in the endometrium of patients with polycystic ovary syndrome

Polycystic ovary syndrome (PCOS) affects approximately 5% of reproductive-age women and is characterized by anovulation and increased androgen production. Despite the ability to correct ovulatory disorders, pregnancy rates remain paradoxically low, and spontaneous pregnancy loss rates are high. To determine whether uterine dysfunction contributed to the adverse reproductive outcomes in PCOS, we assessed the effect of the increased ovarian androgens on a well-characterized gene essential to endometrial receptivity. Up-regulation of HOXA10 in the endometrium is necessary for receptivity to embryo implantation. In vitro, HOXA10 expression was repressed by testosterone but not by dehydroepiandrosterone, dehydroepiandrosterone sulfate, or insulin. Testosterone also prevented the increased expression of HOXA10 previously reported with estradiol or progesterone. Dihydrotestosterone produced an effect similar to that of testosterone, whereas flutamide blocked the testosterone effect. Endometrial biopsies, obtained from women with PCOS, demonstrated decreased HOXA10 mRNA. Testosterone is a novel regulator of HOXA10. Diminished uterine HOXA10 expression may contribute to the diminished reproduction potential of women with PCOS.

Effect of clomiphene citrate on endometrium thickness and echogenic patterns

OBJECTIVE

To study the effect of clomiphene citrate (CC) on the thickness and echogenic pattern of the endometrium using vaginal sonography.

METHOD

In this experimental prospective study, CC was given to 31 women with unexplained infertility. Thickness and echo patterns of the endometrium, as well as estradiol (E2) and progesterone (P) levels, were compared in women taking CC and in control patients during both the late proliferative and midsecretory phases of the menstrual cycle.

RESULTS

Endometrial thickness was significantly thinner in women taking CC (P<0.03) than in controls during the late proliferative phase but there was no significant difference during the midsecretory phase. The endometrial echogenic patterns of women taking CC who had conceived revealed endometrial thicknesses of grade III and grade IV on midsecretory days, but these findings were not significantly different from those of women who had not conceived (P=0.3). Serum E2 level was higher in women taking CC than in the controls on both late proliferative and midsecretory days (P<0.05).

CONCLUSION

CC affects endometrium thickness on late proliferative days but not on midsecretory days, and does not alter the echogenic pattern of the endometrium.

A randomized double-blind comparison of the effects of clomiphene citrate and the aromatase inhibitor letrozole on ovulatory function in normal women

OBJECTIVE

To evaluate the ovarian follicular dynamics of cycle modification with the aromatase inhibitor letrozole compared with clomiphene citrate in normal ovulatory women.

DESIGN

Randomized double-blind controlled trial.

SETTING

Tertiary care hospital.

PATIENT(S)

Nineteen ovulatory female volunteers, ages 18-35 years.

INTERVENTION(S)

Subjects were monitored in one control cycle. Subjects then received either letrozole 2.5 mg daily or clomiphene citrate 50 mg daily on days 5-9 after menses.

MAIN OUTCOME MEASURE(S)

Number of mature follicles, endometrial thickness and endometrial pattern at ovulation, and follicular profiles of LH, FSH, and E(2).

RESULT(S)

The number of mature follicles at the LH surge in natural cycles was 1.0 with an exaggerated response seen for treatment both with clomiphene and letrozole. There was no difference in the endometrial thickness at midcycle during either the natural cycles or the medicated cycles. LH surges and spontaneous ovulation were documented in all natural and medicated cycles. When measured daily, follicular profiles of LH and FSH are similar between the groups in both the natural and medicated cycles. In the medicated cycles, clomiphene results in a significant increase in E(2) levels, while E(2) levels in letrozole-stimulated cycles appeared lower than in natural cycles.

CONCLUSION(S)

Transient inhibition of aromatase activity in the early follicular phase with the aromatase inhibitor letrozole results in stimulation of ovarian folliculogenesis similar to that seen with clomiphene citrate with no apparent adverse effect on endometrial thickness or pattern at midcycle.

Aromatase inhibition for ovarian stimulation: future avenues for infertility management

Ovarian stimulation is applied during infertility management either alone or in conjunction with intrauterine insemination and assisted reproductive technologies. At the present time, the two main medications used for ovarian stimulation include an oral antiestrogen, clomiphene citrate, and injectable gonadotropins. In spite of the high ovulation rate with the use of clomiphene citrate, the pregnancy rate is much lower. In clomiphene citrate failures, gonadotropin injections have generally been used as the next treatment option. Treatment with gonadotropins is difficult to control and characteristically associated with increased risk of severe ovarian hyperstimulation syndrome and high multiple pregnancies. Therefore, an effective oral treatment that could be used without risk of hyperstimulation and with minimal monitoring is the preferred therapy. We hypothesize that aromatase inhibitors can be administered early in the follicular phase to induce ovulation by releasing the hypothalamus or pituitary from estrogen negative feedback. Based on this hypothesis, we have reported the success of aromatase inhibitors in induction and augmentation of ovulation in addition to improving ovarian response to gonadotropin stimulation. Moreover, there are other potential applications for aromatase inhibitors in infertility management, including improving implantation in assisted reproduction and in-vitro maturation.

Metformin therapy improves ovulatory rates, cervical scores, and pregnancy rates in clomiphene citrate-resistant women with polycystic ovary syndrome

OBJECTIVE

To evaluate the effect of metformin therapy on hyperandrogenism, insulin resistance, cervical scores, ovulation, and pregnancy rates in clomiphene citrate-resistant women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective, randomized, double-blind, placebo-controlled study.

SETTING

Infertility clinic of a tertiary referral center.

PATIENT(S)

Fifty-six women with clomiphene citrate-resistant PCOS.

INTERVENTION(S)

Two cycles of oral metformin therapy (850 mg, twice daily) in group I and placebo therapy (twice daily) in group II. Clomiphene citrate (100 mg/day) on cycle days 3-7 of the second cycle in both groups.

MAIN OUTCOME MEASURE(S)

Insulin, T, DHEAS, FSH, LH, body mass index (BMI), waist-to-hip ratio, endometrial thickness, cervical score, ovulation, and pregnancy rates in clomiphene-induced cycles after metformin therapy.

RESULT(S)

Metformin therapy resulted in a significant decrease in total T, LH level, LH/FSH ratio, insulin resistance, and mean BMI. No difference in waist-to-hip ratio, DHEAS level, and fasting insulin level was observed. Clomiphene citrate induction resulted in higher ovulation rates and thicker endometrium in the metformin group than in the placebo group. There was higher cumulative pregnancy rate in the metformin group; however, there was no significant difference in the pregnancy rate between the two groups.

CONCLUSION(S)

Metformin therapy not only decreases hyperandrogenism and insulin resistance but also improves ovulation rates, cervical scores, and pregnancy rates in clomiphene citrate-resistant women with PCOS.