Unexplained infertility: evaluation of treatment with clomiphene citrate and human chorionic gonadotropin

The definition of unexplained infertility: A systematic review

BACKGROUND

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

OBJECTIVES

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

SEARCH STRATEGY

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

DATA COLLECTION AND ANALYSIS

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

MAIN RESULTS

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

CONCLUSIONS

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

Evidence-based guideline: unexplained infertility†

STUDY QUESTION

What is the recommended management for couples presenting with unexplained infertility (UI), based on the best available evidence in the literature?

SUMMARY ANSWER

The evidence-based guideline on UI makes 52 recommendations on the definition, diagnosis, and treatment of UI.

WHAT IS KNOWN ALREADY

UI is diagnosed in the absence of any abnormalities of the female and male reproductive systems after 'standard' investigations. However, a consensual standardization of the diagnostic work-up is still lacking. The management of UI is traditionally empirical. The efficacy, safety, costs, and risks of treatment options have not been subjected to robust evaluation.

STUDY DESIGN, SIZE, DURATION

The guideline was developed according to the structured methodology for ESHRE guidelines. Following formulation of key questions by a group of experts, literature searches, and assessments were undertaken. Papers written in English and published up to 24 October 2022 were evaluated.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Based on the available evidence, recommendations were formulated and discussed until consensus was reached within the guideline development group (GDG). Following stakeholder review of an initial draft, the final version was approved by the GDG and the ESHRE Executive Committee.

MAIN RESULTS AND THE ROLE OF CHANCE

This guideline aims to help clinicians provide the best care for couples with UI. As UI is a diagnosis of exclusion, the guideline outlined the basic diagnostic procedures that couples should/could undergo during an infertility work-up, and explored the need for additional tests. The first-line treatment for couples with UI was deemed to be IUI in combination with ovarian stimulation. The place of additional and alternative options for treatment of UI was also evaluated. The GDG made 52 recommendations on diagnosis and treatment for couples with UI. The GDG formulated 40 evidence-based recommendations-of which 29 were formulated as strong recommendations and 11 as weak-10 good practice points and two research only recommendations. Of the evidence-based recommendations, none were supported by high-quality evidence, one by moderate-quality evidence, nine by low-quality evidence, and 31 by very low-quality evidence. To support future research in UI, a list of research recommendations was provided.

LIMITATIONS, REASONS FOR CAUTION

Most additional diagnostic tests and interventions in couples with UI have not been subjected to robust evaluation. For a large proportion of these tests and treatments, evidence was very limited and of very low quality. More evidence is required, and the results of future studies may result in the current recommendations being revised.

WIDER IMPLICATIONS OF THE FINDINGS

The guideline provides clinicians with clear advice on best practice in the care of couples with UI, based on the best evidence currently available. In addition, a list of research recommendations is provided to stimulate further studies in the field. The full guideline and a patient leaflet are available in www.eshre.eu/guideline/UI.

STUDY FUNDING/COMPETING INTEREST(S)

The guideline was developed by ESHRE, who funded the guideline meetings, literature searches, and dissemination of the guideline in collaboration with the Monash University led Australian NHMRC Centre of Research Excellence in Women's Health in Reproductive Life (CREWHIRL). The guideline group members did not receive any financial incentives; all work was provided voluntarily. D.R. reports honoraria from IBSA and Novo Nordisk. B.A. reports speakers' fees from Merck, Gedeon Richter, Organon and Intas Pharma; is part of the advisory board for Organon Turkey and president of the Turkish Society of Reproductive Medicine. S.B. reports speakers' fees from Merck, Organon, Ferring, the Ostetric and Gynaecological Society of Singapore and the Taiwanese Society for Reproductive Medicine; editor and contributing author, Reproductive Medicine for the MRCOG, Cambridge University Press; is part of the METAFOR and CAPE trials data monitoring committee. E.B. reports research grants from Roche diagnostics, Gedeon Richter and IBSA; speaker's fees from Merck, Ferring, MSD, Roche Diagnostics, Gedeon Richter, IBSA; E.B. is also a part of an Advisory Board of Ferring Pharmaceuticals, MSD, Roche Diagnostics, IBSA, Merck, Abbott and Gedeon Richter. M.M. reports consulting fees from Mojo Fertility Ltd. R.J.N. reports research grant from Australian National Health and Medical Research Council (NHMRC); consulting fees from Flinders Fertility Adelaide, VinMec Hospital Hanoi Vietnam; speaker's fees from Merck Australia, Cadilla Pharma India, Ferring Australia; chair clinical advisory committee Westmead Fertility and research institute MyDuc Hospital Vietnam. T.P. is a part of the Research Council of Finland and reports research grants from Roche Diagnostics, Novo Nordics and Sigrid Juselius foundation; consulting fees from Roche Diagnostics and organon; speaker's fees from Gedeon Richter, Roche, Exeltis, Organon, Ferring and Korento patient organization; is a part of NFOG, AE-PCOS society and several Finnish associations. S.S.R. reports research grants from Roche Diagnostics, Organon, Theramex; consulting fees from Ferring Pharmaceuticals, MSD and Organon; speaker's fees from Ferring Pharmaceuticals, MSD/Organon, Besins, Theramex, Gedeon Richter; travel support from Gedeon Richter; S.S.R. is part of the Data Safety Monitoring Board of TTRANSPORT and deputy of the ESHRE Special Interest Group on Safety and Quality in ART; stock or stock options from IVI Lisboa, Clínica de Reprodução assistida Lda; equipment/medical writing/gifts from Roche Diagnostics and Ferring Pharmaceuticals. S.K.S. reports speakers' fees from Merck, Ferring, MSD, Pharmasure. HRV reports consulting and travel fees from Ferring Pharmaceuticals. The other authors have nothing to disclose.

DISCLAIMER

This guideline represents the views of ESHRE, which were achieved after careful consideration of the scientific evidence available at the time of preparation. In the absence of scientific evidence on certain aspects, a consensus between the relevant ESHRE stakeholders has been obtained. Adherence to these clinical practice guidelines does not guarantee a successful or specific outcome, nor does it establish a standard of care. Clinical practice guidelines do not replace the need for application of clinical judgment to each individual presentation, nor variations based on locality and facility type. ESHRE makes no warranty, express or implied, regarding the clinical practice guidelines and specifically excludes any warranties of merchantability and fitness for a particular use or purpose. (Full disclaimer available at www.eshre.eu/guidelines.).

Optimal lead follicle size for human chorionic gonadotropin trigger in clomiphene citrate and intrauterine insemination cycles: an analysis of 1,676 treatment cycles

OBJECTIVE

To identify the optimal lead follicle size for hCG trigger in clomiphene citrate (CC)-intrauterine insemination (IUI) cycles.

DESIGN

Retrospective cohort study.

SETTING

University-affiliated center.

PATIENT(S)

Patients <40 years of age with ovulatory dysfunction or unexplained infertility undergoing their first CC-IUI cycle.

INTERVENTION(S)

Ovulation induction, hCG trigger, and IUI.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate (CPR) was the primary outcome and was plotted against lead follicle size in increments of 1 mm. Odds ratios with 95% confidence intervals for associations between lead follicle size and CPR were calculated from a multivariable logistic regression model. A receiver operating characteristic (ROC) curve was generated for CPR as a function of lead follicle size.

RESULT(S)

1,676 cycles were included. The overall CPR was 13.8% (232/1,676). There was no difference in baseline demographics or ovulation induction parameters of patients who did or did not conceive. The odds of clinical pregnancy were 2.3 and 2.2 times higher with lead follicle sizes of 21.1-22.0 mm and >22.0 mm, respectively, compared with the referent category of 19.1-20.0 mm. Lead follicle size was an independent predictor of CPR, even after accounting for confounders. A lead follicle size of 22.1 mm corresponded to a sensitivity and specificity of 80.1% and 90.4% for clinical pregnancy, respectively, with an area under the ROC curve of 0.89.

CONCLUSION(S)

hCG administration at a lead follicle size of 21.1-22.0 mm is associated with higher odds of clinical pregnancy in patients undergoing their first CC-IUI cycles for ovulatory dysfunction or unexplained infertility.

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

OBJECTIVE

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

METHODS

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

RECOMMENDATION(S)

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

CONCLUSION(S)

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

Interventions for unexplained infertility: a systematic review and network meta-analysis

BACKGROUND

Clinical management for unexplained infertility includes expectant management as well as active treatments, including ovarian stimulation (OS), intrauterine insemination (IUI), OS-IUI,  and in vitro fertilisation (IVF) with or without intracytoplasmic sperm injection (ICSI).Existing systematic reviews have conducted head-to-head comparisons of these interventions using pairwise meta-analyses. As this approach allows only the comparison of two interventions at a time and is contingent on the availability of appropriate primary evaluative studies, it is difficult to identify the best intervention in terms of effectiveness and safety. Network meta-analysis compares multiple treatments simultaneously by using both direct and indirect evidence and provides a hierarchy of these treatments, which can potentially better inform clinical decision-making.

OBJECTIVES

To evaluate the effectiveness and safety of different approaches to clinical management (expectant management, OS, IUI, OS-IUI, and IVF/ICSI) in couples with unexplained infertility.

SEARCH METHODS

We performed a systematic review and network meta-analysis of relevant randomised controlled trials (RCTs). We searched electronic databases including the Cochrane Gynaecology and Fertility Group Specialised Register of Controlled Trials, the Cochrane Central Register of Studies Online, MEDLINE, Embase, PsycINFO and CINAHL, up to 6 September 2018, as well as reference lists, to identify eligible studies. We also searched trial registers for ongoing trials.

SELECTION CRITERIA

We included RCTs comparing at least two of the following clinical management options in couples with unexplained infertility: expectant management, OS, IUI, OS-IUI, and IVF (or combined with ICSI).

DATA COLLECTION AND ANALYSIS

Two review authors independently screened titles and abstracts identified by the search strategy. We obtained the full texts of potentially eligible studies to assess eligibility and extracted data using standardised forms. The primary effectiveness outcome was a composite of cumulative live birth or ongoing pregnancy, and the primary safety outcome was multiple pregnancy. We performed a network meta-analysis within a random-effects multi-variate meta-analysis model. We presented treatment effects by using odds ratios (ORs) and 95% confidence intervals (CIs). For the network meta-analysis, we used Confidence in Network Meta-analysis (CINeMA) to evaluate the overall certainty of evidence.

MAIN RESULTS

We included 27 RCTs (4349 couples) in this systematic review and 24 RCTs (3983 couples) in a subsequent network meta-analysis. Overall, the certainty of evidence was low to moderate: the main limitations were imprecision and/or heterogeneity.Ten RCTs including 2725 couples reported on live birth. Evidence of differences between OS, IUI, OS-IUI, or IVF/ICSI versus expectant management was insufficient (OR 1.01, 95% CI 0.51 to 1.98; low-certainty evidence; OR 1.21, 95% CI 0.61 to 2.43; low-certainty evidence; OR 1.61, 95% CI 0.88 to 2.94; low-certainty evidence; OR 1.88, 95 CI 0.81 to 4.38; low-certainty evidence). This suggests that if the chance of live birth following expectant management is assumed to be 17%, the chance following OS, IUI, OS-IUI, and IVF would be 9% to 28%, 11% to 33%, 15% to 37%, and 14% to 47%, respectively. When only including couples with poor prognosis of natural conception (3 trials, 725 couples) we found OS-IUI and IVF/ICSI increased live birth rate compared to expectant management (OR 4.48, 95% CI 2.00 to 10.1; moderate-certainty evidence; OR 4.99, 95 CI 2.07 to 12.04; moderate-certainty evidence), while there was insufficient evidence of a difference between IVF/ICSI and OS-IUI (OR 1.11, 95% CI 0.78 to 1.60; low-certainty evidence).Eleven RCTs including 2564 couples reported on multiple pregnancy. Compared to expectant management/IUI, OS (OR 3.07, 95% CI 1.00 to 9.41; low-certainty evidence) and OS-IUI (OR 3.34 95% CI 1.09 to 10.29; moderate-certainty evidence) increased the odds of multiple pregnancy, and there was insufficient evidence of a difference between IVF/ICSI and expectant management/IUI (OR 2.66, 95% CI 0.68 to 10.43; low-certainty evidence). These findings suggest that if the chance of multiple pregnancy following expectant management or IUI is assumed to be 0.6%, the chance following OS, OS-IUI, and IVF/ICSI would be 0.6% to 5.0%, 0.6% to 5.4%, and 0.4% to 5.5%, respectively.Trial results show insufficient evidence of a difference between IVF/ICSI and OS-IUI for moderate/severe ovarian hyperstimulation syndrome (OHSS) (OR 2.50, 95% CI 0.92 to 6.76; 5 studies; 985 women; moderate-certainty evidence). This suggests that if the chance of moderate/severe OHSS following OS-IUI is assumed to be 1.1%, the chance following IVF/ICSI would be between 1.0% and 7.2%.

AUTHORS' CONCLUSIONS

There is insufficient evidence of differences in live birth between expectant management and the other four interventions (OS, IUI, OS-IUI, and IVF/ICSI). Compared to expectant management/IUI, OS may increase the odds of multiple pregnancy, and OS-IUI probably increases the odds of multiple pregnancy. Evidence on differences between IVF/ICSI and expectant management for multiple pregnancy is insufficient, as is evidence of a difference for moderate or severe OHSS between IVF/ICSI and OS-IUI.

Role of thioridazine in unexplained infertility

A total of 452 women with unexplained infertility were selected for the present study. From them 310 women were put on thioridazine tablet (5 mg), 1 h after dinner from the 8th day of the menstrual cycle to the 18th day in each cycle. Coitus was advised about 1-2 h after the drug intake and proper posture was advised to the patients. The other 142 patients were given placebo therapy. Patients were followed up for pregnancy for 1 year which was confirmed by ultrasonographic examination. Ninety-four patients (30.2%) in the study group conceived in contrast to 22 (15.42%) in the control group (P less than 0.001). Incidence of abortions, congenital malformations and perinatal mortality and mode of delivery were not significantly different in the two groups. Thioridazine due to anxiolytic effect in low dosage appears to be promising in the treatment of unexplained infertility.

Aromatase Inhibition Reduces the Dose of Gonadotropin Required for Controlled Ovarian Hyperstimulation

OBJECTIVE

To compare the use of the aromatase inhibitor, letrozole, in conjunction with follicle-stimulating hormone (FSH) injection, and FSH alone for controlled ovarian hyperstimulation (COH) in patients with polycystic ovarian syndrome (PCOS) or ovulatory infertility.

METHODS

This nonrandomized study included two study groups: 26 patients with PCOS and 63 with ovulatory infertility (unexplained infertility [41 patients], male factor infertility [17 patients], and endometriosis [5 patients]), who received letrozole in addition to FSH; and two control groups: 46 PCOS patients and 308 with ovulatory infertility (unexplained infertility [250 patients], male factor infertility [42 patients], and endometriosis [16 patients], who received FSH only. All patients had intrauterine insemination (IUI). Main outcome measures included dose of FSH used per cycle, number of preovulatory follicles greater than 16 mm in diameter, cancellation rate, and pregnancy rate.

RESULTS

The FSH dose required for ovarian stimulation was significantly lower when letrozole was used in both study groups compared to the control groups without a significant difference in number of follicles greater than 16 mm. IUI cancellation rate was significantly lower with letrozole treatment in PCOS patients. In women with PCOS, clinical pregnancy rate per completed IUI cycle was 26.5% in the letrozole plus FSH group versus 18.5% in the FSH-only group. In ovulatory infertility patients, the pregnancy rate was similar in both study and control groups (11%).

CONCLUSION

We believe that inhibition of estrogen synthesis by aromatase inhibition will release the estrogenic negative feedback, resulting in an increase in endogenous FSH secretion. Moreover, by inhibiting conversion of androgens into estrogens, accumulating androgens may increase follicular sensitivity to FSH. Such a protocol has the potential to lower FSH treatment cost and may improve response for low responders who require high FSH doses during ovarian stimulation.

Evidence-based approach to unexplained infertility: a systematic review

OBJECTIVE

To summarize the available evidence for the efficacy of various treatments for unexplained infertility.

DESIGN

Systematic review.

SETTING

Not applicable.

PATIENT(S)

Patients aged 18-40 years with unexplained infertility.

INTERVENTION(S)

Clomiphene citrate, letrozole, timed intercourse, IUI, gonadotropins, IVF, and IVF-intracytoplasmic sperm injection.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate, ongoing pregnancy rate, and live birth rate.

RESULT(S)

Thirteen studies with a total of 3,081 patients were identified by systematic search and met inclusion criteria. The available literature demonstrates that expectant management may be comparable to treatment with clomiphene and timed intercourse or IUI. Clomiphene may be more effective than letrozole, and treatment with gonadotropins seems more effective, albeit with significantly higher risk of multiple gestations than either oral agent. On the basis of current data, IVF, with or without intracytoplasmic sperm injection, is no more effective than gonadotropins with IUI for unexplained infertility.

CONCLUSION(S)

Adequately powered, randomized controlled trials that compare all of the available treatments for unexplained infertility are needed. Until such data are available, clinicians should individualize the management of unexplained infertility with appropriate counseling regarding the empiric nature of current treatment options including IVF.

Oral Drugs for Unexplained Infertility

Of the infertile couples unable to conceive without any identifiable cause, 30 % are defined as having unexplained infertility. Management depends on duration of infertility and age of female partner. The treatment of unexplained infertility is empirical, and many different regimens have been used. Among these are expectant management, ovarian stimulation with clomiphene citrate, gonadotropins and aromatase inhibitors, fallopian tube sperm perfusion, tubal flushing, intrauterine insemination, gamete intrafallopian transfer, and IVF. The first approach to treatment of unexplained infertility generally is the use of drugs that stimulate oocyte production. For over four decades, the first-line treatment for ovarian stimulation in unexplained infertility has been clomiphene citrate. Multiple reports suggest that aromatase inhibitors may be effective alternative agents for ovarian stimulation in couples with unexplained infertility. Their administration is reported to be associated with monofollicular development in most cases, which may result in enhanced fertility and a reduced risk of ovarian hyperstimulation and multiple births, as compared to current standard therapies such as gonadotropin and clomiphene. Despite world evidence to the contrary, letrozole has been banned for use for infertility management in India since 2011.

Letrozole, Gonadotropin, or Clomiphene for Unexplained Infertility

BACKGROUND

The standard therapy for women with unexplained infertility is gonadotropin or clomiphene citrate. Ovarian stimulation with letrozole has been proposed to reduce multiple gestations while maintaining live birth rates.

METHODS

We enrolled couples with unexplained infertility in a multicenter, randomized trial. Ovulatory women 18 to 40 years of age with at least one patent fallopian tube were randomly assigned to ovarian stimulation (up to four cycles) with gonadotropin (301 women), clomiphene (300), or letrozole (299). The primary outcome was the rate of multiple gestations among women with clinical pregnancies.

RESULTS

After treatment with gonadotropin, clomiphene, or letrozole, clinical pregnancies occurred in 35.5%, 28.3%, and 22.4% of cycles, and live birth in 32.2%, 23.3%, and 18.7%, respectively; pregnancy rates with letrozole were significantly lower than the rates with standard therapy (gonadotropin or clomiphene) (P=0.003) or gonadotropin alone (P<0.001) but not with clomiphene alone (P=0.10). Among ongoing pregnancies with fetal heart activity, the multiple gestation rate with letrozole (9 of 67 pregnancies, 13%) did not differ significantly from the rate with gonadotropin or clomiphene (42 of 192, 22%; P=0.15) or clomiphene alone (8 of 85, 9%; P=0.44) but was lower than the rate with gonadotropin alone (34 of 107, 32%; P=0.006). All multiple gestations in the clomiphene and letrozole groups were twins, whereas gonadotropin treatment resulted in 24 twin and 10 triplet gestations. There were no significant differences among groups in the frequencies of congenital anomalies or major fetal and neonatal complications.

CONCLUSIONS

In women with unexplained infertility, ovarian stimulation with letrozole resulted in a significantly lower frequency of multiple gestation but also a lower frequency of live birth, as compared with gonadotropin but not as compared with clomiphene. (Funded by the National Institutes of Health and others; ClinicalTrials.gov number, NCT01044862.).

Infertility: evaluation and initial management

Treating the infertile client with competence and compassion is within the scope of practice for advanced practice clinicians. However, due to both a lack of emphasis on infertility treatment in many advanced practice education programs and confusion regarding diagnosis and treatment by many practitioners, infertility is often undertreated by these providers. A basic infertility evaluation, patient counseling, and prescriptive therapy with oral ovulation-inducing agents by a knowledgeable practitioner is cost-effective and may result in successful pregnancy in women who otherwise may not be adequately and quickly treated prior to referral to a reproductive endocrinologist. A diagnosis of infertility is often stressful and frustrating for a couple. Midwives and advanced practice nurses are uniquely qualified to provide both compassionate care and competent treatment during this time. This article provides the clinician with an overview of infertility diagnosis, evaluation, and initial management with lifestyle modifications and oral ovulation-inducing agents.

Ovarian stimulation and intrauterine insemination at the quarter centennial: implications for the multiple births epidemic

Ovarian stimulation and intrauterine insemination (OS/IUI), a mainstay of current infertility therapy and a common antecedent to IVF, is a significant driver of the multiple births epidemic. Redress of this challenge, now marking its quarter centennial, will require a rethinking of current practice patterns. Herein we explore prospects for prevention, mitigation, and eventual resolution. We conclude that the multiple births attributable to OS/IUI may not be entirely preventable but that the outlook for their mitigation is promising, if in need of solidification. Specifically, we observe that low-dose (≤ 75 IU) gondotropin, clomiphene, and especially off-label letrozole regimens outperform high-dose (≥ 150 IU) gonadotropin counterparts in the gestational plurality category while maintaining comparable per-cycle pregnancy rates. Accordingly we recommend that, subject to appropriate exceptions, high-dose gonadotropin regimens be used sparingly and that whenever possible they be replaced with emerging alternatives. Finally, we posit that OS/IUI is not likely to be superseded by IVF absent further commoditization and thus greater affordability.

Clomiphene citrate for unexplained subfertility in women

BACKGROUND

The effectiveness of clomiphene citrate has been demonstrated in the treatment of subfertility associated with infrequent or irregular ovulation. The physiologic effects and clinical benefits in ovulatory women with unexplained subfertility are less clear. The drug is associated with an increased risk of multiple pregnancy and a suggestion of potentially increased ovarian cancer risks. In light of these concerns, defining the effectiveness of clomiphene citrate for ovulatory women with unexplained subfertility is extremely important.

OBJECTIVES

To determine the effectiveness of clomiphene citrate in improving pregnancy outcomes in women with unexplained subfertility, used in a dose range of 50 to 250 mg for up to 10 days. The primary outcome was live births.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group Specialised Register (June 2009), the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2009, Issue 2), MEDLINE (1966 to June 2009), EMBASE (1980 to June 2009) and reference lists of articles.

SELECTION CRITERIA

Only randomised controlled trials were included. Quasi-randomised designs were excluded.

DATA COLLECTION AND ANALYSIS

Fourteen potentially relevant trials were identified of which seven were included in this review. All trials were assessed for risk of bias using standardised Menstrual Disorders and Subfertility Group methodology.

MAIN RESULTS

Data relating to 1159 participants from seven trials were collated. There was no evidence that clomiphene citrate was more effective than no treatment or placebo for live birth (odds ratio (OR) 0.79, 95% CI 0.45 to 1.38; P = 0.41) or for clinical pregnancy per woman randomised both with intrauterine insemination (IUI) (OR 2.40, 95% CI 0.70 to 8.19; P = 0.16), without IUI (OR 1.03, 95% CI 0.64 to 1.66; P = 0.91) and without IUI but using human chorionic gonadotropin (hCG) (OR 1.66, 95% CI 0.56 to 4.80; P = 0.35). It should be noted that heterogeneity between studies ranged from 34% to 58% using the I(2) statistic.

AUTHORS' CONCLUSIONS

There is no evidence of clinical benefit of clomiphene citrate for unexplained fertility. When making this treatment choice, potential side effects should be discussed. These include the increased risk of multiple pregnancy and the concern that use for more that 12 cycles has been associated with a three-fold increase in risk of ovarian cancer.

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.

Role of an estrogen-upregulated 64.0-kDa uterine fluid glycoprotein in improving fertility in women

OBJECTIVE

To evaluate the significance of an estrogen-upregulated 64.0-kDa human uterine fluid (hUF) glycoprotein in relation to promotion of fertility.

DESIGN

Prospective study.

SETTING

Department of Assisted Reproductive Biology Unit, Institute of Reproductive Medicine, Kolkata. India.

PATIENT(S)

Sixty-three women with unexplained infertility having normal ovulatory cycle with normal endocrine profile and 18 parous women.

INTERVENTION(S)

Women either received no stimulation (n = 35) or were stimulated with clomiphene citrate (CC) alone (100 mg/day from day 3 to day 7; n = 56) or in combination with pure FSH (75 IU on day 3 and day 8; n = 54) and were subjected to IUI. Parous women (n = 18) receiving no treatment served as control and were followed-up for spontaneous ovulation.

MAIN OUTCOME MEASURE(S)

Uterine fluid protein profile, relative intensity of 64.0-kDa protein, number of mature follicles, endometrial thickness, and pregnancy.

RESULT(S)

Expression of the 64.0-kDa protein exhibited positive correlation with prevailing estradiol levels, but the degree of the protein response to estrogen was comparatively blunted in the CC-incorporated cycles. Endometrial thickness and pregnancy outcomes correlated positively with the expression of the protein.

CONCLUSION(S)

The 64.0-kDa hUF protein perhaps plays a role in endometrial receptivity to support pregnancy. Failure of pregnancy despite documented ovulation in CC-stimulated cycles may be due to its attenuating effects on expression of the protein.

Basal ovarian cysts and clomiphene citrate ovulation induction cycles

OBJECTIVE

To evaluate the effect of simple basal ovarian cysts in patients undergoing infertility treatment with clomiphene citrate. To evaluate the effect of clomiphene citrate on pretreatment simple ovarian cysts.

METHODS

Prospective cohort trial of 84 infertility patients undergoing ovulation induction with clomiphene citrate. Patients with basal ovarian cysts of 10 mm or greater (n = 42) were compared with patients without ovarian cysts (n = 42). The main outcome measure was ovulation determined by menstrual cycle day 21 progesterone level. Each patients with an ovarian cyst was also evaluated for persistence or resolution of the cyst in association with ovulation and cyst size. Pretreatment and posttreatment transvaginal ultrasound examinations were performed on all patients.

RESULTS

Demographic data were similar among the groups. The mean ovarian cyst size was 17.4 +/- 5.8 mm. Patients in the ovarian cyst group were significantly less likely to ovulate (80.9% versus 97.6%, P < .05), but did not differ in pregnancy rate compared with patients without baseline ovarian cysts (4.8% versus 11.9%, P = .43). Persistent ovarian cysts occurred in 36.7% of the patients. The initial size of the cyst did not predict cyst persistence.

CONCLUSION

According to these data, basal ovarian cysts significantly reduce ovulatory events in patients treated with clomiphene citrate.

LEVEL OF EVIDENCE

II-2.

Tamoxifen citrate for women with unexplained infertility

OBJECTIVE

To assess whether administration of tamoxifen citrate (TMX) to women with unexplained infertility is beneficial. The primary outcome was the clinical pregnancy rate.

STUDY DESIGN

In a prospective randomized trial, 66 consecutive women with unexplained infertility were recruited for the study. Thirty-six women received TMX at a 20-mg dosage and 30 women received no ovulation-induction drugs.

RESULTS

Fourteen patients in the TMX group stopped taking TMX, and observations were terminated because of antiestrogenic effects. The pregnancy rate (PR) per patient and the PR per cycle were significantly decreased (P < 0.005) in the TMX group than in the spontaneous group. Kaplan-Meier tests showed that the cumulative PR in the TMX group was significantly lower than in the spontaneous group (P < 0.05). Ten of 14 patients who had stopped taking TMX became pregnant in spontaneous cycles.

CONCLUSIONS

Administration of tamoxifen to women with unexplained infertility is not efficacious in terms of increasing the clinical PR.

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.

A randomized trial of superovulation with two different doses of letrozole

OBJECTIVE

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

DESIGN

Prospective randomized trial.

SETTING

Academic teaching hospital.

PATIENT(S)

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

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Conception rates in clomiphene citrate cycles with and without hormone supplementation: a pilot study

OBJECTIVE

A trial was conducted to examine the effects of a timed sequence of hormone supplementation (HS) with oral estradiol (E(2)) and vaginal progesterone (P) following clomiphene citrate (CC) therapy to determine if this regimen can increase pregnancy rates in CC cycles.

METHODS

This study was a randomized, open-label study. Seventy-one oligo-ovulatory women were randomized into one of two groups; those who received CC plus HS (n = 34) and those who received no HS (n = 37). All subjects received 100 mg CC orally from cycle days 3 to 7. Subjects randomized to HS started oral E(2) at a dose of 1.5 mg BID on cycle day 8. All subjects monitored urine luteinizing hormone (LH) levels starting on cycle day 10; additionally, intercourse was encouraged starting on cycle day 10. Subjects receiving HS discontinued E(2) with LH surge and started using vaginal progesterone gel (Prochieve 8%) daily for 2 weeks starting 3 days after LH surge. All subjects had a pregnancy test (Assure) 2 weeks after LH surge. If pregnancy occurred, the subject continued using vaginal progesterone gel daily for an additional 10 weeks.

RESULTS

Sixty-five (65) subjects (31 CC plus HS and 34 no HS) completed the study. Fifty of the 65 subjects (77%) (23 [74%] CC plus HS, 27 [79%] no HS) who completed the study ovulated. The mean (range) progesterone (P) concentration for these 50 subjects was 1662.6 (340 to 5690) ng/dL, and mean and median P levels were slightly higher, but not statistically significant, in the HS group compared with the no HS group. Pregnancy rates were clinically, but not statistically, different between the treatment groups. Of the 50 responders, 12% became pregnant (17% CC plus HS, 7% no HS).

CONCLUSION

These findings show a potential supportive effect on pregnancy rates in the CC plus oral estradiol and vaginal progesterone gel group compared to CC alone that needs to be confirmed in a larger study.

The aromatase inhibitor anastrozole is associated with favorable embryo development and implantation markers in mice ovarian stimulation cycles

OBJECTIVE

To investigate the embryonic and endometrial effects of anastrozole in preimplantation and implantation phases in FSH-induced cycles in mice.

DESIGN

Blind randomized study.

SETTING

University research laboratory.

ANIMAL(S)

Twenty-seven mature female mice.

INTERVENTION(S)

Single-dose anastrozole (25 mg/kg [0.75 mg]), recombinant FSH (5 IU/mL), and hCG (5 IU/mL) (n = 9); recombinant FSH (5 IU/mL) and hCG (5 IU/mL) (n = 9); or sterile saline (1 mL) (n = 9). The morning of finding the vaginal plug was designated as day 1 of embryonic development (E1). Three mice from each group were sacrificed on E1 and embryos aspirated from uterine tubes. The rest of the mice were sacrificed on E2.5-3 and uteruses removed.

MAIN OUTCOME MEASURE(S)

Embryo quality, endometrial histologic evaluation, and immunohistochemical analysis of tumor necrosis factor-alpha, leukemia inhibitory factor, laminin, and collagen IV staining.

RESULT(S)

Anastrozole use in FSH-induced cycles not only caused an increase in preimplantation receptivity and implantation but also supported release of implantation markers. The enhanced embryo development seen in this study would explain the higher implantation because embryo development is synchronized with endometrial development.

CONCLUSION(S)

In mice, the use of anastrozole in FSH-induced cycles has a positive effect on embryo quality and implantation. This effect might be species dependent, and human studies are needed.

Present concept of unexplained infertility

Despite improvements in both diagnostic assessment and treatment of infertile couples, many couples still have no explanation for their infertility. Unexplained infertility (the failure to conceive of a couple in whom no definitive cause for infertility can be found) has an incidence of 10-20% in all infertile couples. The incidence varies with the population studied and with the criteria used. Unexplained infertility is not an absolute condition but rather a relative inability to conceive, and many of these couples may conceive without treatment. The treatment options for unexplained infertility are several and the treatment results are promising. Expectant management can be recommended if the woman is under 28-30 years of age and the infertility duration is less than 2-3 years. In vitro fertilization (IVF) has revolutionized the treatment of infertile couples, as well as profoundly increasing the basic understanding of human reproduction. IVF can be used as both a diagnostic and a therapeutic tool in couples with unexplained infertility. The pregnancy rates with IVF are good, at 40% per treatment cycle. In addition, the outcome of pregnancies among women with unexplained infertility is generally comparable to that of spontaneous and other pregnancies using assisted reproductive technologies.

A comparison of ovulation suppression and ovulation stimulation in the treatment of endometriosis-associated infertility

This study compares ovulation stimulation or suppression with the pregnancy rate among infertile couples with endometriosis. The design is a nonrandomized, prospective, multicentered cohort analytic study. Two hundred and ninety-seven couples with laparoscopy-proven endometriosis were analyzed: 68 received no therapy, 42 received clomiphene and 74 received danazol. Forty patients (22%) conceived and pregnancy rates were similar in each treatment group. The relative likelihood of pregnancy associated with clomiphene was 2.9 (95% confidence limits 1.2-7.1); the relative likelihood of pregnancy with danazol was 1.02 (95% confidence limits 0.5-2.3). This study suggests that pregnancy rates during clomiphene treatment could be superior to expectant therapy, while pregnancy rate after danazol is similar to no treatment.

Unexplained infertility: a review of diagnosis, prognosis, treatment efficacy and management

The dilemma of unexplained infertility posed by Southam in 1960 remains today: despite advances in the diagnostic assessment of infertility, many couples still have no explanation for their infertility. Even the most sophisticated evaluation of semen, ovulation and genital tract competence cannot reveal all of the possible defects in the complex process leading to conception. Because it arises from these shortcomings in our knowledge of fertilization and from our inability to utilize all of the current knowledge, unexplained infertility is a challenge for both biological and clinical research. This paper attempts to summarize some clinical issues in the management of unexplained infertility: the prevalence of the disorder, problems in the definition and possible explanations for the existence of this diagnostic category. It reviews outcome-based clinical publications as a guide to decision-making on what diagnostic tests to use, provides a summary of the untreated prognosis and evaluates study results that may serve as a basis for treatment decisions in this puzzling diagnostic category of infertility.

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

OBJECTIVE

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

DESIGN

Retrospective analysis.

SETTING

Academic teaching hospital.

PATIENT(S)

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

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

Oral versus injectable ovulation induction agents for unexplained subfertility

BACKGROUND

Oral (anti-oestrogens) and injectable (gonadotrophins) ovulation induction agents have been used to increase the number of eggs produced by a woman per cycle in treatment for unexplained subfertility. It is unclear whether there are significant advantages of one type of treatment over the other in this context or in terms of fertility.

OBJECTIVES

To assess the efficacy of oral versus injectable ovulation induction agents for unexplained subfertility.

SEARCH STRATEGY

The search strategy of the Menstrual Disorders and Subfertility Group was used for the identification of relevant randomised controlled trials.

SELECTION CRITERIA

All trials where oral ovulation induction agents were compared with injectable ovulation induction agents in treatment groups generated by randomisation, from couples with unexplained subfertility, were considered for inclusion in the review.

DATA COLLECTION AND ANALYSIS

Five randomised controlled trials, including a total of 231 identified couples with unexplained subfertility, were found and included in this review. All trials were assessed for quality criteria. The studied outcomes were pregnancy, live birth, miscarriage, multiple birth, occurrence of ovarian hyperstimulation syndrome and cycle cancellation.

MAIN RESULTS

Where trials with important co-interventions were excluded, there was no significant difference in the odds of beneficial outcomes for oral versus injectable ovulation induction agents - live birth per couple (OR 0.06, 95%CI 0.00-1.15), pregnancy per woman (OR 0.33, 95%CI 0.09-1.20); nor of detrimental outcomes for injectable versus oral agents - miscarriage (OR 0.11, 95%CI 0.00-2.84); there were no reported cases of multiple births, cases of ovarian hyperstimulation or discontinued cycles consequent upon overstimulation. Where trials with the co-intervention of a human chorionic gonadotrophin trigger injection (given only in the injectable ovulation induction agent treatment arm) were not excluded there was no significant difference in the odds of live birth per couple (OR 0.40, 95%CI 0.15-1.08). However oral ovulation induction agents had significantly reduced odds of pregnancy per woman compared to injectable ovulation induction agents (OR 0.41, 95%CI 0.17-0.80). For detrimental outcomes, there were no significant differences in the odds of miscarriage (OR 0.61, 95%CI 0.09-4.01) and multiple birth (OR 1.08, 95%CI 0.16-7.03) for injectable versus oral agents. No data were available concerning the occurrence of ovarian hyperstimulation syndrome nor cycle cancellation.

REVIEWER'S CONCLUSIONS

There is insufficient evidence to suggest that oral agents are inferior or superior to injectable agents in the treatment of unexplained subfertility. Information on harms is sketchy, and remains compatible with large differences in either direction. Much larger trials than have previously been undertaken are required to provide information on relative harms as well as benefits.

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

OBJECTIVE

To use aromatase inhibition for induction of ovulation in women in whom clomiphene citrate (CC) treatment was unsuccessful.

DESIGN

Prospective trial in infertility patients treated with CC.

SETTING

Two tertiary-referral infertility clinics associated with the Division of Reproductive Sciences, University of Toronto.

PATIENT(S)

Twelve patients with anovulatory polycystic ovary syndrome (PCOS) and 10 patients with ovulatory infertility, all of whom had previously received CC with an inadequate outcome (no ovulation and/or endometrial thickness of < or =0.5 cm).

INTERVENTION(S)

The aromatase inhibitor letrozole was given orally in a dose of 2.5 mg on days 3-7 after menses.

MAIN OUTCOME MEASURE(S)

Occurrence of ovulation, endometrial thickness, and pregnancy rates.

RESULT(S)

With CC treatment in patients with PCOS, ovulation occurred in 8 of 18 cycles (44.4%), and all ovulatory cycles for the women included in this study had endometrial thickness of < or =0.5 cm. In 10 ovulatory patients, 15 CC cycles resulted in a mean number of 2.5 mature follicles, but all cycles had endometrial thickness of < or =0.5 cm on the day of hCG administration. With letrozole treatment in the same patients with PCOS, ovulation occurred in 9 of 12 cycles (75%) and pregnancy was achieved in 3 patients (25%). In the 10 patients with ovulatory infertility, letrozole treatment resulted in a mean number of 2.3 mature follicles and mean endometrial thickness of 0.8 cm. Pregnancy was achieved in 1 patient (10%).

CONCLUSION(S)

Oral administration of the aromatase inhibitor letrozole is effective for ovulation induction in anovulatory infertility and for increased follicle recruitment in ovulatory infertility. Letrozole appears to avoid the unfavorable effects on the endometrium frequently seen with antiestrogen use for ovulation induction.

Intrauterine insemination before transfer of frozen-thawed embryos may improve the pregnancy rate for couples with unexplained infertility: preliminary results of a randomized prospective study

OBJECTIVE

To evaluate whether a combination of IUI and frozen-thawed embryo transfer (FT-ET) with ovulation induction would improve the PR in couples with unexplained infertility.

DESIGN

Prospective, randomized study.

SETTING

In Vitro Fertilization Unit, Tel Aviv Sourasky Medical Center, Tel Aviv, Israel.

PATIENT(S)

Sixty-two patients with unexplained infertility were assigned into two groups. The study group was composed of 32 women (38 cycles) who received ovulation induction followed by IUI and FT-ET. The control group was composed of 30 women (33 cycles) who received ovulation induction followed by FT-ET.

INTERVENTION(S)

Clomiphene citrate (CC) and hCG, IUI, and FT-ET.

MAIN OUTCOME MEASURE(S)

Pregnancy rate (PR) per cycle, PR per ET.

RESULT(S)

In the study group, the PR per cycle and per ET were 36.8% (14 of 38) and 40.6% (13 of 32), respectively. In the control group, the PR per cycle and per ET were 12.1% (4 of 33) and 14.3% (4 of 28), respectively. Statistically significant differences were found between the two groups in the PR per cycle (P=.02) and PR per ET (P=.03). No statistically significant difference was found between the groups for the stage in which the embryos were cryopreserved, the survival cleavage rates after thawing, grading of thawed embryos, and number of embryos transferred.

CONCLUSION(S)

In couples with unexplained infertility, the PR may be improved by combining IUI and FT-ET with ovulation induction. Performing IUI before thawing may prevent treatment cancellation in cycles with no surviving embryos.

The management of unexplained infertility

Unexplained infertility is a diagnosis made by exclusion after all of the standard investigations have revealed no abnormality (1). The range of the prevalence is from 6 to 60 percent (23), depending on the diagnostic criteria. This article reviews the literature in the management of unexplained infertility; published data suggest no benefit of danazol or bromocriptine. The empirical use of clomiphene citrate suggests that ovarian stimulation using clomiphene citrate can double the spontaneous pregnancy rate (52, 58, 59). Induction of ovulation with human menopausal gonadotrophin (hMG) yields an overall pregnancy rate between 2 and 26 percent per cycle (68, 74). These results seem to be lower than those reported for in vitro fertilization (IVF) or gamete intrafallopian transfer (GIFT) procedures in similar patients (25-30 percent (92, 95)). Based on the literature, a rational treatment plan for treating infertility in couples with unexplained infertility includes up to four cycles of clomiphene citrate with or without intrauterine insemination (IUI). Superovulation with hMG and IUI or stimulated intrauterine insemination (SIUI) is the next step for three-cycle treatments and if unsuccessful, one of the variants of assisted reproductive techniques (ART) should be considered.

TARGET AUDIENCE

Obstetricians & Gynecologists, Family Physicians.

LEARNING OBJECTIVES

After completion of this article, the reader will understand the appropriate tests and work up for unexplained infertility, the various treatment options for the unexplained infertility couple including which drugs are effective and not effective, and to be able to outline an appropriate treatment plan for such patients.

Efficacy of treatment for unexplained infertility

OBJECTIVE

To analyze the efficacy and cost-effectiveness of alternative treatments for unexplained infertility.

DESIGN

Retrospective analysis of 45 published reports.

SETTING

Clinical practices.

PATIENT(S)

Couples who met criteria for unexplained infertility. Women with Stage I or Stage II endometriosis were included.

INTERVENTION(S)

Observation; clomiphene citrate (CC); gonadotropins (hMG); IUI; and GIFT and IVF.

MAIN OUTCOME MEASURE(S)

Clinical pregnancy rate.

RESULT(S)

Combined pregnancy rates per initiated cycle, adjusted for study quality, were as follows: no treatment = 1.3%-4.1%; IUI = 3.8%; CC = 5.6%; CC + IUI = 8.3%; hMG = 7.7%; hMG + IUI = 17.1%; IVF = 20.7%; GIFT = 27.0%. The estimated cost per pregnancy was $10,000 for CC + IUI, $17,000 for hMG + IUI, and $50,000 for IVF.

CONCLUSION(S)

Clomiphene citrate + IUI is a cost-effective treatment for unexplained infertility. If this treatment fails, hMG + IUI and assisted reproduction are efficacious therapeutic options.

The effects of clomiphene citrate on normally ovulatory women

OBJECTIVE

To investigate the efficacy of clomiphene citrate (CC) on normally ovulatory women who complained of infertility.

DESIGN

A randomized study.

SETTING

University Hospital.

PATIENT(S)

Thirty-three normally ovulatory women with unexplained infertility.

INTERVENTION(S)

Eighteen women received CC at a 50-mg dosage. Fifteen women received no ovulation-induction drugs.

MAIN OUTCOME MEASURES

The pregnancy rate (PR) per patient, the PR per cycle, and the cumulative pregnancy rate.

RESULT(S)

Seven patients in the CC group stopped taking CC, and observations were terminated because of antiestrogenic effects. The pregnancy rate (PR) per patient and the PR per cycle were significantly decreased (P < 0.005) in the CC group (4 of 18 [22.2%] and 4 of 66 [6.1%], respectively) than in the spontaneous group (11 of 15 [73.3%] and 11 of 52 [21.2%], respectively). Kaplan-Meier tests showed that the cumulative pregnancy rate in the CC group was significantly lower than in the spontaneous group (P < 0.05). Five of seven patients who had stopped taking CC became pregnant in spontaneous cycles.

CONCLUSION(S)

Administration of CC to normally ovulatory women is not efficacious in terms of increasing the pregnancy rate.

Clinical uses of antiestrogens

An antiestrogen is a compound that blocks the action of estrogen. Most synthetic antiestrogens have agonistic or antagonistic activity depending on the tissue and the endogenous estrogen mileu. The triphenylethylene derivatives, clomiphene and tamoxifen, are the antiestrogens in greatest clinical use. Their biologic effects, clinical indications, and risks are reviewed. Novel antiestrogens which are beginning to be studied clinically include the benzothiophene derivative, raloxifene and the "pure" antiestrogens such as ICI 182,780. New clinical indications for existing compounds as well as the development of novel antiestrogens may lead to better treatment options for endocrine-dependent conditions.

A three step protocol for the treatment of idiopathic subfertility

650 couples with idiopathic subfertility (mean duration: 5.7 year, range 2-21 years) were treated during 2870 cycles by three assisted conception methods (each involving mild ovarian stimulation): I timed intercourse (TI), II intrauterine insemination (IUI). III in vitro fertilization/embryo transfer (IVF/ET). Treatment started with TI in most cases and then changed to IUI after three to six cycles. Couples who failed to conceive were treated after another 3-9 cycles by IVF/ET. An overall cumulative pregnancy rate of 80.2% was reached after 18 treatment months. The pregnancy rates per treatment cycle were: TI 5.3%, IUI 6.9%, IVF/ET 15.8% (per oocyte retrieval).

Cycle abnormalities in infertile women with regular menstrual cycles: effects of clomiphene citrate treatment

OBJECTIVE

To investigate the incidence and nature of cycle abnormalities and the effect of clomiphene citrate (CC) treatment in women with apparently ovulatory cycles and unexplained infertility.

DESIGN

Nonrandomized, open study of patients before and during treatment.

SETTING

The Reproductive Medicine Clinic of a District General Hospital.

PATIENTS

Thirty-five women with regular, apparently ovulatory menstrual cycles and unexplained infertility.

INTERVENTIONS

Detailed ultrasound and hormonal cycle tracking was performed before and during treatment with CC.

MAIN OUTCOME MEASURES

Serial ultrasound scans and measurements of serum LH, FSH, E2, and P.

RESULTS

Before treatment, 54% of cycles were uniovulatory, 40% were characterized by cyst formation, and 6% were characterized by poor follicular growth. Fifty-one percent of pretreatment cycles had normal hormone profiles, 31% had defective luteal phases, 14% had increased early follicular phase serum FSH levels, and 9% had increased early follicular phase serum LH levels. Treatment with CC reduced the incidence of cyst formation to 9% and the incidence of luteal phase defects to 3%. However, 28% of CC-treated cycles showed ultrasound features of overstimulation and 51% had high follicular phase E2 peaks so that only 34% of CC-treated cycles had normal hormone profiles.

CONCLUSIONS

Cycle abnormalities are common in unexplained infertility. The incidence of cyst formation and luteal phase defects, the most common abnormalities in this group, is reduced by CC treatment.

Outcome of donor versus husband insemination in couples with unexplained infertility treated by in vitro fertilization and embryo transfer

OBJECTIVE

To examine the IVF-ET outcome of couples with unexplained infertility treated by husband versus donor sperm.

DESIGN

A retrospective analysis of the IVF-ET outcome of couples with unexplained infertility treated by either husband or donor sperm and in a subgroup of patients treated simultaneously by husband and donor sperm.

SETTING

IVF Unit, Serlin Maternity Hospital, Tel Aviv, Israel.

PATIENTS

Couples diagnosed as having unexplained infertility underwent IVF at our Unit; included were 96 couples treated by husband insemination (group A), 27 couples who received donor insemination because of azoospermia (group B), and 8 couples who sought donor insemination after having previously failed IVF (group C).

RESULTS

No statistically significant difference was found between groups A and B regarding age of the females, duration of infertility, number of IVF cycles, fertilization rate, number of ETs, and pregnancy rate. Oocytes collected in group C were subdivided further into two groups: 45 were incubated with husband sperm and 46 were incubated with donor sperm. Fertilization rates were 46.6% and 50%, respectively. One pregnancy occurred.

CONCLUSION

In couples with unexplained infertility who had undergone IVF-ET with husband insemination, the fertilization and pregnancy rates were similar to those of couples who were treated by donor sperm.