The effects of clomiphene citrate on normally ovulatory women

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.

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.

A retrospective analysis of ovarian stimulation with letrozole in women undergoing artificial insemination by donor

The aim of this retrospective study was to determine the clinical pregnancy rate in women undergoing letrozole ovarian stimulation and artificial insemination by donor (AID). Between 2012 and 2015, 130 natural cycles, 939 letrozole cycles and 130 letrozole plus gonadotrophin cycles were conducted. Letrozole cycles were divided into three groups according to LH concentration on the day of HCG administration (LH <10 mIU/ml and follicle size ≥18 cm; LH ≤10 to <20 mIU/ml; and LH ≥20 mIU/ml). Pregnancy rates were 17.3%, 22.4% and 26.8%, respectively (P = 0.012). In women given 10 mIU/ml LH or more, logistic regression identified oestradiol (OR 1.002, 95% CI, 1.000 to 1.004, P = 0.029) and leading follicle size (OR 0.861, 95% CI, 0.772 to 0.960, P = 0.007) as significant predictive factors of pregnancy rate; the higher the oestradiol and the smaller the follicles, the better the pregnancy rate. The pregnancy rate was significantly higher in the letrozole plus gonadotrophin group than the letrozole group (P = 0.04). Better pregnancy rates can be achieved if LH surge occurs before HCG administration, especially with higher oestradiol and lower follicle size; treatment with letrozole plus gonadotrophin was significantly more effective than letrozole alone in AID.

Luteal phase clomiphene citrate for ovulation induction in women with polycystic ovary syndrome

PURPOSE

The aim was to test a new protocol of luteal phase administration of clomiphene citrate (CC) for ovulation induction in women with polycystic ovary syndrome (PCOS).

METHODS

This was a prospective, randomized, controlled trial. Two hundred and fifty-two women (cycles) with PCOS were utilized to create two groups. Patients in Group 1 (126 patients) received 100 mg of CC daily for 5 days starting on day 5 of menses, and patients in Group 2 (126 patients) received 100 mg of CC daily for 5 days starting the next day after finishing medroxyprogesterone acetate (MPA) (before withdrawal bleeding). The main outcome measures were the number of growing and mature follicles, serum E2 (in pg/mL), serum progesterone (in ng/mL) levels, endometrial thickness (in mm), pregnancy, and miscarriage rates.

RESULTS

The total number of follicles and the number of follicles ≥14 mm during stimulation were significantly greater in Group 2. The endometrial thickness at the time of human chorionic gonadotrophin (hCG) administration was significantly greater in Group 2 as compared to Group 1 (7.84 ± 1.22 and 8.81 ± 0.9, respectively). Serum E2 levels were also significantly higher (p < 0.05) in Group 2 as compared to Group 1 (449.61 ± 243.45 vs. 666.09 ± 153.41 pg/mL). Pregnancy occurred in 13 patients (10.3 %) in Group 2 and in 11 patients (8.7 %) in Group 1. The difference was not statistically significant.

CONCLUSION

Luteal phase administration of CC in patients with PCOS leads to increased follicular growth and endometrial thickness, which might result in a higher pregnancy rate.

Adding L-carnitine to clomiphene resistant PCOS women improves the quality of ovulation and the pregnancy rate. A randomized clinical trial

OBJECTIVE

To evaluate the effectiveness of L-carnitine on improving the ovulation and pregnancy rates as well as adverse metabolic indices in clomiphene-resistant PCOS.

DESIGN

Single center, double blinded, superiority, randomized controlled clinical trial.

SETTING

Women's Health Hospital, Assiut University.

METHODS

One hundred and seventy women diagnosed with PCOS were found to be clomiphene resistant. The women were randomly allocated into two groups: Group A (n=85), where patients received 250 mg clomiphene citrate from day three until day seven of the cycle plus L-carnitine (LC) 3g daily; and Group B (n=85) received 250 mg clomiphene citrate with placebo.

OUTCOME

Primary outcome is cumulative clinical pregnancy rate. Secondary outcomes are changes in serum glucose level and lipid profile.

RESULTS

The combination of L-carnitine and CC significantly improve both the ovulation and the cumulative pregnancy rates in clomiphene resistant PCOS (55 (64.4%) vs. 15 (17.4%) and 44 (51.5) % vs. 5 (5.8) %). The number of stimulated follicles reaching ≥17 mm diameter was significantly more in Group A to Group B (2.2 ± 0.77 vs. 0.16 ± 0.79; p<0.0001). Group A needed significantly fewer days for adequate follicular maturation, had a thicker endometrium and higher oestradiol concentration at the time of human chorionic gonadotrophin injection (10.1 ± 0.1mm vs. 6.8 ± 0.4mm; p<0.0001). The same group had a higher mean luteal-phase serum progesterone compared with the control group (13.55 ± 0.99 vs. 10.6 ± 0.98 ng; p<0.0001). A significant difference was found regarding the clinical pregnancy rates (42 (49.4%) vs. (1) 1.1% respectively p value <0.0001).

CONCLUSION

Adding L-carnitine when treating clomiphene-resistant PCOS patients not only improved the quality of ovulation and the pregnancy rate with an acceptable patient tolerability, but also enhanced the patient lipid profile and body mass index.

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.

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.

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.

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.

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

OBJECTIVE

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

DESIGN

Prospective, randomized, and blinded clinical study.

SETTING

Academic tertiary institute.

PATIENT(S)

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

INTERVENTION(S)

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

MAIN OUTCOME MEASURE(S)

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

RESULT(S)

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

CONCLUSION(S)

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

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.

Hormonal profile and endometrial morphology in letrozole-controlled ovarian hyperstimulation in ovulatory infertile patients

OBJECTIVE

To evaluate the clinical response and endometrial morphology during the implantation window on ovarian hyperstimulation with the aromatase inhibitor letrozole in infertile ovulatory women.

DESIGN

Prospective trial in infertile patients.

SETTING

Tertiary care hospital.

PATIENT(S)

Eight ovulatory infertile patient candidates for ovarian superovulation.

INTERVENTION(S)

Subjects were monitored in one control cycle. In the next cycle, they received letrozole 5.0 mg daily on days 3 through 7 after menses.

MAIN OUTCOME MEASURE(S)

Number of ovulatory follicles; dominant follicle diameter; endometrial thickness; hormonal profile of FSH, LH, E(2), A, T, and P; endometrial histological dating; and pinopode formation assessed by scanning electron microscopy.

RESULT(S)

Cycles stimulated with letrozole resulted in more ovulatory follicles than did natural cycles (mean +/- SD 2.0 +/- 0.9 vs. 1.0 +/- 0.0), which attained a greater preovulatory diameter (mean +/- SD 23.8 +/- 2.7 vs. 19.3 +/- 2.1 mm), with similar endometrial thickness at midcycle compared with spontaneous cycles. Endocrine profile of medicated cycles was characterized on day 7 by increased levels of LH (5.9 +/- 0.8 vs. 3.5 +/- 0.4 IU/mL), reduced E(2) (98.4 +/- 11.4 vs. 161.5 +/- 14.7 pmol/L), and elevated androgens. Preovulatory and midsecretory E(2) were similar to spontaneous cycle, and P levels during midluteal phase were significantly elevated (44.2 +/- 4.6 vs. 27.7 +/- 4.6 pmol/L). Endometrial morphology during the implantation window in letrozole-stimulated cycles was characterized by in-phase histological dating and pinopode expression on scanning electron microscopy.

CONCLUSION(S)

Letrozole induces moderate ovarian hyperstimulation in ovulatory infertile patients with E(2) levels similar to spontaneous cycles and higher midluteal P, leading to both a normal endometrial histology and development of pinopodes, considered to be relevant markers of endometrial receptivity.

A trial of a new regimen with clomiphene citrate administration to reduce the antiestrogenic effects on reproductive end organs

OBJECTIVE

To determine the endocrinological and clinical outcomes of a 3-day clomiphene citrate (CC) regimen and compare it with the classical 5-day clomiphene citrate regimen.

STUDY DESIGN

59 patients, diagnosed with Class II ovulatory deficiency according to the criteria defined by WHO, were randomized into two groups. Patients in Group I received 50mg per day of CC for 3 days starting on the first day of the cycle during 72 cycles. Group II received 50mg per day of CC for 5 days starting on the fifth day during 64 cycles.

RESULT(S)

The ovulation rate was significantly higher in Group II (78.11%) compared to Group I (63.88%) (P < 0.05). However, the implantation rate was higher in Group I than Group II.

CONCLUSION

We observed that starting CC on the first day of the cycle for 3 days would lead to higher implantation rates compared to the classical 5-day CC therapy.

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.

Follicular growth, endometrial thickness, and serum estradiol levels in spontaneous and clomiphene citrate-induced cycles

OBJECTIVES

To evaluate follicular growth, endometrial thickness, and serum estradiol levels in spontaneous cycles and cycles induced by clomiphene citrate (CC).

METHODS

A 2-year prospective study of spontaneous cycle followed by a CC-induced cycle to compare paired data. Twenty couples with unexplained infertility were recruited from the Infertility Clinic of the Jawaharlal Institute of Postgraduate Medical Education and Research. An oral dose of 150 mg of CC was administered on days 5 through 9 of the CC-induced cycle. Each woman was evaluated using transvaginal sonography and serum estradiol level estimation from day 10 of the menstrual cycle until ovulation. Results were analyzed using the paired t-test.

RESULTS

The leading follicular diameter was significantly larger, endometrial thickness was significantly decreased, and serum estradiol levels were significantly higher in the follicular phase of CC-induced cycles.

CONCLUSIONS

Clomiphene citrate-induced cycles showed different follicular, endometrial growth patterns, and serum estradiol levels compared with spontaneous cycles.

Reducing the incidence of twins and triplets

Multiple pregnancy rates remain high after assisted conception because of a misconceived assumption that transferring three or more embryos will maximize pregnancy rates. Maternal morbidity is sevenfold greater in multiple pregnancies than in singletons, perinatal mortality rates are fourfold higher for twins and sixfold higher for triplets, while cerebral palsy rates are 1-1.5% in twin and 7-8% in triplet pregnancies. Therefore, multiple pregnancies must be considered a serious adverse outcome of assisted reproductive techniques. Primary prevention of multiple pregnancies is the solution. The overwhelming evidence presented in this chapter demonstrates that limiting the embryo transfer in in vitro fertilization to two embryos would significantly reduce adverse maternal and perinatal outcomes by reducing the incidence of high order multiple pregnancies without reducing take-home-baby rates. Secondary prevention by multifetal pregnancy reduction is effective, but not acceptable to all patients. New developments in blastocyst culture, single embryo transfer, embryo cryopreservation and pre-implantation aneuploidy exclusion, should allow improvements in pregnancy rates without increasing multiple pregnancies.

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.

[Benefits and risks of ovarian stimulation before intrauterine insemination]

Performance of intra-uterine insemination (IIU) is generally advocated as a first line therapy for infertility related to cercical hostility, male factor, unexplained infertility or mild endometriosis. IIU are usually performed following stimulation of ovulation, even in absence of anovulation. However the rationale for such a systematic ovulation induction is still questionable. Indeed, while an overall assessment of ovarian stimulation tends to conclude to a beneficial effect of these treatments in unexplained or some male infertility, it is clear that no definitive conclusion can be drawn. Indeed, the methodology in many published series is mostly inadequate, data are usually not analysed according to the type of infertility or to the female hormonal features. Finally, adverse effects are imperfectly descripted. A more accurate analysis of these data in relation to the number of recruited follicles definitively shows that, if a bifollicular development is associated with a significant increase in the pregnancy rates, there is no advantage to stimulate further the ovary. Indeed, surpassing the recruitment of two follicles would lead to dramatically increase the risk of OHSS and multiple pregnancies. Thus, further investigations including prospective, randomized studies are needed to better define what should be the most adequate regimen of ovulation induction. Specifically, tailoring the rate of multifollicular development according to the duration, the type of infertility (etiology; primary or secondary; female age) would prove to be a safer approach for getting pregnancy as well as avoiding adverse effects. Such a policy remains to be determined in the light of further clinical studies conducted in the more appropriate manner.

Clomiphene citrate for unexplained subfertility in women

OBJECTIVES

Clomiphene citrate appears to increase ovulation in women with oligo-ovulatory subfertility. It may also work in women with unexplained subfertility, perhaps by correcting an unidentifiable ovulatory dysfunction. The objective of this review was to assess the effects of clomiphene citrate in women with unexplained subfertility.

SEARCH STRATEGY

The Cochrane Subfertility Review Group specialised register of controlled trials was searched".

SELECTION CRITERIA

Randomised trials of clomiphene citrate (doses of 50 to 250 milligrams per day up to 10 days) compared to placebo or no treatment in women with unexplained subfertility.

DATA COLLECTION AND ANALYSIS

Trial quality was assessed and data were extracted independently by two reviewers.

MAIN RESULTS

Five studies were included. Four trials were of crossover design, and quality of the randomisation was variable. Compared to placebo, clomiphene citrate was associated with an increase in pregnancy rates. The odds ratio for pregnancy per patient was 2.38 (95% confidence interval 1.22 to 4.62). The odds ratio of pregnancy per cycle was 2.5 (95% confidence interval 1.35 to 4.62).

REVIEWER'S CONCLUSIONS

Clomiphene citrate appears to modestly improve pregnancy rates in women with unexplained subfertility. However adverse effects include a possible ovarian cancer risk and risk of multiple pregnancy.

Prospective randomized double-blind trial of the correlation between time of administration and antiestrogenic effects of clomiphene citrate on reproductive end organs

OBJECTIVE

To investigate whether the timing of administration of clomiphene citrate (CC) affects hormone levels, follicular recruitment, reproductive end organs, and pregnancy rates.

DESIGN

Prospective, randomized, double-blind trial.

SETTING

Academic center.

PATIENT(S)

Twenty-three patients with unexplained infertility.

INTERVENTION(S)

Twenty-three patients with unexplained infertility underwent 45 cycles of CC and IUI. For each cycle, patients were randomized either to receive 100 mg of CC on days 1-5 and placebo on days 5-9 (study group), or placebo on days 1-5 and CC on days 5-9 (control group).

MAIN OUTCOME MEASURE(S)

The difference in uterine artery PI, number of follicles, endometrial thickness, and pregnancy rates.

RESULT(S)

Gonadotropins and E2 levels, as well as uterine artery pulsatility index, were significantly higher in the study group on day 5. In addition, in the study group, a longer time interval existed between finishing CC and IUI (8 versus 6 days; MD = 2 days; 95% CI = 1-3) and the pregnancy rate was higher than in the control group (6 versus 0; OR = 15.1; 95% CI = 1.1-72.4).

CONCLUSION(S)

Clomiphene citrate commenced on day 1 of the menstrual cycle, rather than day 5, results in more rapid follicular growth, a longer CC-free period before IUI, and higher pregnancy rates. Although methodologically sound, our results should be taken with some degree of caution because they are based on a relatively small number of patients.