Transvaginal sonographic assessment of follicular and endometrial growth in spontaneous and clomiphene citrate cycles

Factors associated with spontaneous miscarriage risk in IUI treatment: A retrospectively cohort of 31,933 cycles

To determine the factors associated with intrauterine insemination (IUI) miscarriages and reduce the IUI miscarriage rate, a retrospective study was performed by reviewing 31,933 IUI cycles from 2006 to 2018. The overall there were 14.50% clinical pregnancies, and 16.74% miscarriages. Logistic regression revealed the following three predictive variables: females aged ≥ 35 years (odds ratio [OR] = 2.131; p < 0.001), spontaneous miscarriage history (OR = 1.513; p = 0.005), and ovarian stimulation schemes such as clomiphene citrate (CC) (OR = 1.459; p = 0.003). The natural cycle led to a lower miscarriage rate for patients without spontaneous miscarriage history both for those over 35 years old (OR = 0.402; p = 0.034) and for those under 35 years old (OR = 0.806; p = 0.017). Gonadotropin (Gn) showed the lowest miscarriage rate for patients without abortion history, though no significant differences were found. Patients under 35 with a history of miscarriage were protected from miscarriage by using CC and Gn together (OR = 0.516; p = 0.032). No significant differences were found between various ovarian protocols when patients with abortion history were aged ≥ 35 years (p = 0.606). CC + Gn showed the lowest miscarriage rate. In conclusion, the natural cycle could be suggested for infertility couples to minimize abortion risk. When ovarian induction is required, CC + Gn had the lowest miscarriage rate for women with a history of spontaneous miscarriage while Gn is more successful for individuals without such a history.

Emulating a target trial of the comparative effectiveness of clomiphene citrate and letrozole for ovulation induction

STUDY QUESTION

What are the comparative pregnancy outcomes in women who receive up to six consecutive cycles of ovulation induction with letrozole versus clomiphene citrate?

SUMMARY ANSWER

The risks of pregnancy, livebirth, multiple gestation, preterm birth, neonatal intensive care unit (NICU) admission and congenital malformations were higher for letrozole compared with clomiphene in participants with polycystic ovarian syndrome (PCOS), though no treatment differences were observed in those with unexplained infertility.

WHAT IS KNOWN ALREADY

Randomized trials have reported higher pregnancy and livebirth rates for letrozole versus clomiphene among individuals with PCOS, but no differences among those with unexplained infertility. None of these trials were designed to study maternal or neonatal complications.

STUDY DESIGN, SIZE, DURATION

We emulated a hypothetical trial of the comparative effectiveness of letrozole versus clomiphene citrate for ovulation induction among all women, then stratified by PCOS and unexplained infertility status. We used real-world data from a large healthcare claims database in the USA (2011-2015).

PARTICIPANTS/MATERIALS, SETTING, METHODS

We analyzed data from 18 120 women who initiated letrozole and 49 647 women who initiated clomiphene during 2011-2014, and who were aged 18-45 years with no history of diabetes, thyroid disease, liver disease or breast cancer and had no fertility treatments for 3 months before trial initiation. The treatment strategies were clomiphene citrate or letrozole for six consecutive cycles. The outcomes were pregnancy, livebirth, multiple gestation, preterm birth, small for gestational age (SGA), NICU admission and major congenital malformations. We estimated the probability of each outcome under each strategy via pooled logistic regression and used standardization to adjust for confounding and selection bias due to loss to follow-up.

MAIN RESULTS AND THE ROLE OF CHANCE

The estimated probabilities of pregnancy, livebirth and neonatal outcomes were similar under each strategy, both overall and among individuals with unexplained infertility. Among women with PCOS, the probability of pregnancy was 43% for letrozole vs 37% for clomiphene (risk difference [RD] = 6.0%; 95% CI: 4.4, 7.7) in the intention-to-treat analyses. The corresponding probability of livebirth was 32% vs 29% (RD = 3.1%; 95% CI: 1.5, 4.8). In per protocol analyses, the risk of multiple gestation was 19% vs 9%, the risk of preterm birth was 20% vs 15%, the risk of SGA was 5% vs 3%, the risk of NICU admission was 22% vs 16% and the risk of congenital malformation was 8% vs 2% among those with a livebirth.

LIMITATIONS, REASONS FOR CAUTION

We cannot completely rule out the possibility of residual confounding by body mass index or duration of infertility. However, we adjusted for proxies identified in administrative data and results did not change.

WIDER IMPLICATIONS OF THE FINDINGS

Our findings suggest that for women with unexplained infertility, the two treatments result in comparable probabilities of a livebirth. For women with PCOS, letrozole appears slightly more effective for attaining a livebirth. Neonatal outcomes were similar for the two treatments among women with unexplained infertility; we did not confirm the hypothesized higher risk of adverse neonatal outcomes for clomiphene versus letrozole. The risks of adverse neonatal outcomes were slightly greater among women with PCOS who were treated with letrozole versus clomiphene. It is likely that these effects are partially mediated through an increased risk of multiple gestation among women who received letrozole.

STUDY FUNDING/COMPETING INTEREST(S)

This work was supported by the National Institute of Child Health and Human Development (R01HD088393). Y.-H.C. reports grants from the American Heart Association (834106) and NIH (R01HD097778). P.R. reports grants from the National Institutes of Health. J.H. reports grants from the National Institutes of Health, the Agency for Healthcare Research and Quality, and the California Health Care Foundation during the conduct of the study; and consulting for several health care delivery organizations including Cambridge Health Alliance, Columbia University, University of Southern California, Community Servings, and the Delta Health Alliance. S.H.-D. reports grants from the National Institutes of Health and the US Food and Drug Administration during the conduct of the study; grants to her institution from Takeda outside the submitted work; consulting for UCB (biopharmaceutical company) and Roche; and being an adviser for the Antipsychotics Pregnancy Registry and epidemiologist for the North American Antiepileptics Pregnancy Registry, both at Massachusetts General Hospital. M.A.H. reports grants from the National Institutes of Health and the U.S. Veterans Administration during the conduct of the study; being a consultant for Cytel; and being an adviser for ProPublica.

TRIAL REGISTRATION NUMBER

N/A.

Determining the optimal follicle size at trigger in patients undergoing ovarian stimulation with a clomiphene citrate plus gonadotropin and GnRH antagonist protocol for in vitro fertilization

OBJECTIVE

Determine the optimal follicle size at trigger in clomiphene citrate-based IVF protocols.

STUDY DESIGN

This is a retrospective cohort study performed in at a single academic institution that included first IVF cycles with clomiphene citrate-based protocols at our center between 01/01/2013-03/31/2019. Patients were dichotomized by whether they had ≥2 follicles >20 mm on trigger day. Group A consisted of patients with <2 follicles >20 mm on trigger day and Group B consisted of patients with ≥2 follicles >20 mm on trigger day. The primary outcome was the number of mature oocytes retrieved. Secondary outcomes included pregnancy and live birth rates.

RESULTS

A total of 635 patients were included: (Group A = 399 patients and Group B = 236 patients). The median (IQR) diameter of the largest follicle was 20.0 mm (19.0-21.0) in Group A and 22.7 mm (21.8-24.0) in Group B (p < 0.001). Among the entire cohort, mean number of oocytes retrieved was significantly higher in Group B (9.9 ± 6.5; RR 1.08 (95% CI 1.03-1.14)) compared to Group A (9.2 ± 6.3). In a subgroup analysis of patients in the upper quartile for age (≥41.7 years), Group B had significantly more oocytes retrieved (8.1 ± 5.9 vs. 6.7 ± 4.5; RR 1.23 (95% CI 1.10-1.38)), more mature oocytes retrieved (6.0 ± 4.0 vs. 5.2 ± 3.4; RR 1.16 (95% CI 1.02-1.33)), and more zygotes (4.7 ± 3.5 vs. 3.6 ± 2.8; RR 1.32 (95% CI 1.13-1.55)). In the secondary analysis, pregnancy and live birth rates after fresh transfer were similar between groups.

CONCLUSIONS

In clomiphene citrate-based IVF protocols, administering the ovulatory trigger at larger follicle sizes yielded more total oocytes retrieved without a significant difference in mature oocyte number. In older patients, larger follicle sizes at trigger yielded more mature oocytes and zygotes per retrieval. Based on these results, in older patients it may be advantageous to administer the ovulatory trigger in clomiphene-based IVF cycles when two or more follicles measures >20 mm. However, this benefit was not observed when assessed among all ages combined.

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

OBJECTIVE

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

DESIGN

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

SETTING

Multicenter randomized controlled trial.

PATIENTS

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

INTERVENTIONS

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

MAIN OUTCOME MEASURES

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION NUMBER

NCT01044862.

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.

IUI: review and systematic assessment of the evidence that supports global recommendations

BACKGROUND

IUI with or without ovarian stimulation (OS) has become a first-line treatment option for many infertile couples, worldwide. The appropriate treatment modality for couples and their clinical management through IUI or IUI/OS cycles must consider maternal and perinatal outcomes, most notably the clinical complication of higher-order multiple pregnancies associated with IUI-OS. With a current global emphasis to continue to decrease maternal and perinatal mortality and morbidity, the World Health Organization (WHO) had established a multi-year project to review the evidence for the establishment of normative guidance for the implementation of IUI as a treatment to address fertility problems, and to consider its cost-effectiveness for lower resource settings.

OBJECTIVE AND RATIONALE

The objective of this review is to provide a review of the evidence of 13 prioritized questions that cover IUI with and without OS. We provide summary recommendations for the development of global, evidence-based guidelines based upon methodology established by the WHO.

SEARCH METHODS

We performed a comprehensive search using question-specific relevant search terms in May 2015. For each PICO (Population, Intervention, Comparison and Outcomes) drafted by WHO, specific search terms were used to find the available evidence in MEDLINE (1950 to May 2015) and The Cochrane Library (until May 2015). After presentation to an expert panel, a further hand search of references in relevant reviews was performed up to January 2017. Articles that were found to be relevant were read and analysed by two investigators and critically appraised using the Cochrane Collaboration's tool for assessing risk of bias, and AMSTAR in case of systematic reviews. The quality of the evidence was assessed using the GRADE system. An independent expert review process of our analysis was conducted in November 2016.

OUTCOMES

This review provides an assessment and synthesis of the evidence that covers 13 clinical questions including the indications for the use of IUI versus expectant management, the sperm parameters required, the best and optimal method of timing and number of inseminations per cycle, prevention strategies to decrease multiple gestational pregnancies, and the cost-effectiveness of IUI versus IVF. We provide an evidence-based formulation of 20 recommendations, as well as two best practice points that address the integration of methods for the prevention of infection in the IUI laboratory. The quality of the evidence ranges from very low to high, with evidence that may be decades old but of high quality, however, we further discuss where critical research gaps in the evidence remain.

WIDER IMPLICATIONS

This review presents an evidence synthesis assessment and includes recommendations that will assist health care providers worldwide with their decision-making when considering IUI treatments, with or without OS, for their patients presenting with fertility problems.

Ultrasound in Infertility Treatments

Ultrasound (US) is very useful in diagnosing causes of infertility. Pelvic masses, mullerian anomalies, ovarian reserve, and tubal patency can all be assessed using ultrasonographic techniques. US has also proven to be a very useful aid in managing infertility treatments. In this chapter, we review the uses of US in monitoring follicular development, assessing the endometrium during treatment, and as an aid to embryo transfer during in vitro fertilization.

Randomized Trial Comparing the Effect of Endometrial Shedding With Medroxyprogesterone Acetate With Random Start of Clomiphene Citrate for Ovulation Induction in Oligo-ovulatory and Anovulatory Women

OBJECTIVE

A recent retrospective study demonstrated that anovulatory infertile women who did not have a progestogen-induced withdrawal bleed before treatment with clomiphene citrate (CC) had higher pregnancy rates than women who had a withdrawal bleed and those who had spontaneous menstrual bleeding. We sought to assess endometrial thickness at the time of ovulation in oligo-ovulatory and anovulatory women who took CC with or without a preceding progestogen-induced withdrawal bleed.

METHODS

We conducted a pilot randomized trial in which women with infertility and oligomenorrhea or amenorrhea were randomly assigned to take either CC after a withdrawal bleed induced by medroxyprogesterone acetate (MPA) 10 mg daily for 10 days or to take CC without such a bleed. Study participants underwent cycle monitoring with ultrasound assessment of endometrial thickness at the time of LH surge or a human chorionic gonadotropin trigger, followed by timed intercourse or intrauterine insemination. Women who had not ovulated by cycle day 21 took an increased dose of CC, with or without an MPA-induced withdrawal bleed, to a maximum of three cycles. Participants and nurses were asked to complete a questionnaire about the study.

RESULTS

There was no significant difference in endometrial thickness on the day of LH surge or human chorionic gonadotropin trigger between women who had a progestogen-induced withdrawal bleed and those who did not (P = 0.65). On average, the time to ovulation was 15 days longer in women who took MPA than in women who did not, but this difference was not statistically significant (P = 0.65). Satisfaction with the study was reported as high by both patients and nurses.

CONCLUSION

In anovulatory or oligo-ovulatory women treated with CC, we found no significant difference in endometrial thickness whether or not the use of CC was preceded by a withdrawal bleed induced by MPA.

Letrozole as the first-line treatment of infertile women with poly cystic ovarian syndrome (PCOS) compared with clomiphene citrate: A clinical trial

Background:

The purpose of this study was to determine the efficacy and safety of letrozole on ovulation induction and pregnancy in comparison with clomiphene citrate in PCOS patients.

Materials and Methods:

The study was based on prospective randomized clinical trial comparing the efficacy of letrozole as the first-line management of the PCOS patients in comparison to clomiphene citrate during 2009 to 2011 and was performed in one private infertility clinic. The study included 100 patients divided into 2 equal groups.

Results:

Pregnancy occurred in 29 of 50 patients in letrozole group (58%) and 24 of 51 patients in clomiphene group (47%). The difference was not statistically significant (P value = 0.23). Thirty patients in clomiphene group and 36 patients in letrozole group showed regular menses after or during the treatment course. No significant difference between the 2 groups was observed (P value = 0.21).

Conclusion:

Our findings suggest letrozole and clomiphene citrate are equally effective for induction of ovulation and achieving pregnancy in patients with PCOS.

The association between follicular size at the time of spontaneous rupture and pregnancy rates in clomiphene citrate treated PCOS patients in coit cycles

OBJECTIVE

To investigate the follicular size at spontaneous rupture on pregnancy rate in patients with polycystic ovary syndrome (PCOS) undergoing clomiphene citrate (CC) ovulation.

DESIGN

Cross-sectional study.

PATIENTS AND METHODS

One hundred and four women with ovulatory cycles after use of CC followed by ultrasound to determine the follicle size at the time of rupture, which was subsequently correlated with the occurrence of pregnancy or not in coit cycles.

RESULTS

In the group of follicular rupture at a mean diameter ≤25 mm (n = 54), pregnancy rate was 35.1% and when follicular rupture occurred at a mean diameter >25 mm (n = 50), it was 34% (p > 0.05). When different diameters at follicular rupture were randomly correlated with the pregnancy rate, there was no significant difference.

CONCLUSION

Our data suggest that the occurrence of pregnancy after ovulation induction with CC in women with PCOS is not associated with follicle size at the time of rupture.

Does optimal follicular size in IUI cycles vary between clomiphene citrate and gonadotrophins treatments?

OBJECTIVE

To evaluate pregnancy-related leading follicles during ovulation induction and superovulation with clomiphene citrate (CC) or gonadotropin.

DESIGN

Retrospective cohort.

PATIENTS

Five hundred and forty-two women who underwent a total of 615 treatment cycles with CC or gonadotropin.

INTERVENTION

We evaluated the effects of CC and gonadotropin on the leading follicles, clinical pregnancy rates and miscarriage rate.

RESULTS

The number of follicles larger than 15 mm in the different protocols was comparable. In those treated with CC, the diameter of the dominant follicles before human chorionic gonadotropins (hCG) trigger in the conception cycles (20.4 ± 1.2 mm) was significantly larger than in the non-conception cycles (18.8 ± 1.9 mm). In women treated with gonadotropin, the diameter of the leading follicle in the conception cycles (18.5 ± 1.7 mm) was comparable to that in the non-conception cycles (18.2 ± 1.7 mm). The pregnancy-related diameter of the leading follicle in CC cycles (20.4 ± 1.2 mm) was significantly larger than that in gonadotropin cycles (18.8 ± 1.9 mm; p = 0.001; 95% CI, -2.2 to -0.9).

CONCLUSION

Pregnancy-related diameter of the leading follicle in CC cycles is significantly larger than that in gonadotropin cycles and the best time for hCG trigger in the CC cycle is when the leading follicle reaches 20 mm.

The M-OVIN study: does switching treatment to FSH and / or IUI lead to higher pregnancy rates in a subset of women with world health organization type II anovulation not conceiving after six ovulatory cycles with clomiphene citrate - a randomised controlled trial

BACKGROUND

Clomiphene citrate (CC) is first line treatment in women with World Health Organization (WHO) type II anovulation and polycystic ovary syndrome (PCOS). Whereas 60% to 85% of these women will ovulate on CC, only about one half will have conceived after six cycles. If women do not conceive, treatment can be continued with gonadotropins or intra-uterine insemination (IUI). At present, it is unclear for how many cycles ovulation induction with CC should be repeated, and when to switch to ovulation induction with gonadotropins and/or IUI.

METHODS/DESIGN

We started a multicenter randomised controlled trial in the Netherlands comparing six cycles of CC plus intercourse or six cycles of gonadotrophins plus intercourse or six cycles of CC plus IUI or six cycles of gonadotrophins plus IUI.Women with WHO type II anovulation who ovulate but did not conceive after six ovulatory cycles of CC with a maximum of 150 mg daily for five days will be included.Our primary outcome is birth of a healthy child resulting from a pregnancy that was established in the first eight months after randomisation. Secondary outcomes are clinical pregnancy, miscarriage, multiple pregnancy and treatment costs. The analysis will be performed according to the intention to treat principle. Two comparisons will be made, one in which CC is compared to gonadotrophins and one in which the addition of IUI is compared to ovulation induction only. Assuming a live birth rate of 40% after CC, 55% after addition of IUI and 55% after ovulation induction with gonadotrophins, with an alpha of 5% and a power of 80%, we need to recruit 200 women per arm (800 women in total).An independent Data and Safety Monitoring Committee has criticized the data of the first 150 women and concluded that a sample size re-estimation should be performed after including 320 patients (i.e. 80 per arm).

DISCUSSION

The trial will provide evidence on the most effective, safest and most cost effective treatment in women with WHO type II anovulation who do not conceive after six ovulatory cycles with CC with a maximum of 150 mg daily for five days. This evidence could imply the need for changing our guidelines, which may cause a shift in large practice variation to evidence based primary treatment for these women.

TRIAL REGISTRATION NUMBER

Netherlands Trial register NTR1449.

Clomiphene citrate versus tamoxifen for ovulation induction in women with PCOS: a prospective randomized trial

OBJECTIVE

To reevaluate the efficacy of induction of ovulation with CC versus TMX in a group of anovulatory subfertile women with PCOS in a randomized controlled trial.

STUDY DESIGN

A prospective randomized controlled study in which 371 PCOS patients were randomly allocated into two treatment groups: group A (187 patients) where women received CC and group B (184 patients) where they received Tamoxifen for one treatment cycle. The outcome measures were number of growing and mature follicles, serum E(2) (pg/ml), serum progesterone (ng/ml) and endometrial thickness, the occurrence of pregnancy and miscarriage.

RESULTS

The number of stimulated follicles reaching ≥ 16 mm diameter was significantly more in the CC group compared to Tamoxifen stimulated group (2.1 SD ± 0.1 vs. 1.1 SD ± 0.7, p<0.0001). The endometrium at the time of hCG administration was significantly thicker in the TMX group (10.1 ± 0.1mm vs. 9.3 ± 0.4mm, p<0.0001). Ovulation occurred in 120/187 cycles (64%) in the CC group and 95/184 cycles (51.6%) in the TMX group with a significant difference between two groups in favors of clomiphene (p=0.01). Serum E(2), on the day of hCG administration, was significantly higher in the clomiphene group (p<0.0001). Pregnancy occurred in 35/187 cycles in group A (18.7%) and 20/184 cycles (10.8%) in group B and the difference was statistically significant (p=0.04).

CONCLUSIONS

Clomiphene citrate is more successful than tamoxifen as a first line therapy for ovulation induction in women with PCOS.

Aromatase inhibitors for ovulation induction and ovarian stimulation

Aromatase inhibitors (AIs) were originally developed for the treatment of advanced breast cancer in postmenopausal women. Their use in reproductive medicine has been extensively studied in the past decade. We reviewed the current strategies for ovulation induction for anovulatory women, mostly women with polycystic ovarian syndrome (PCOS), and the scientific basis for use of AIs in reproductive medicine. The AI, letrozole, is effective in ovulation induction in women with PCOS resistant to clomifene citrate and ovarian stimulation for intrauterine insemination and in vitro fertilization (IVF). Letrozole is an attractive option with its oral route of administration, cost, safety profile and effectiveness in ovulation induction and ovarian stimulation. Letrozole has the potential to be the first-line treatment option for ovulation induction in PCOS women, while its use in ovarian stimulation for IVF deserves further study.

The association between follicular size on human chorionic gonadotropin day and pregnancy rate in clomiphene citrate treated polycystic ovary syndrome patients

OBJECTIVE

To examine leading follicle size on human chorionic gonadotropin (hCG) day and pregnancy rate in anovulatory polycystic ovary syndrome (PCOS) patients treated with clomiphene citrate (CC).

DESIGN

Retrospective cohort study.

SETTING

Fertility clinics in women's health centers.

PATIENTS

Data on 291 infertile women with PCOS and irregular cycles who underwent 685 CC treatment cycles were used. Only cycles with one or two follicles >14 mm were included. hCG was administered once the leading follicle reached the size of 17-24 mm.

MAIN OUTCOME MEASURE(S)

Pregnancy rates in relation to leading follicle size.

RESULTS

Mono/bi-follicular response was observed in 418 cycles. Pregnancy rates were highest (13.6-18.6%) when hCG was administered in the presence of an 18-22 mm follicle, lowest with 17 mm, 23 mm and 24 mm (8.8%, 8.8% and 5.7%, respectively). No differences were observed in pregnancy rates between mono and bi-follicular cycles.

CONCLUSIONS

In CC treatment, hCG should be administered when follicular size is at the range of 18-22 mm.

Reproductive ecology and the endometrium: physiology, variation, and new directions

Endometrial function is often overlooked in the study of fertility in reproductive ecology, but it is crucial to implantation and the support of a successful pregnancy. Human female reproductive physiology can handle substantial energy demands that include the production of fecund cycles, ovulation, fertilization, placentation, a 9-month gestation, and often several years of lactation. The particular morphology of the human endometrium as well as our relative copiousness of menstruation and large neonatal size suggests that endometrial function has more resources allocated to it than many other primates. The human endometrium has a particularly invasive kind of hemochorial placentation and trophoblast that maximizes surface area and maternal-fetal contact, yet these processes are actually less efficient than the placentation of some of our primate relatives. The human endometrium and its associated processes appear to prioritize maximizing the transmission of oxygen and glucose to the fetus over efficiency and protection of maternal resources. Ovarian function controls many aspects of endometrial function and thus variation in the endometrium is often a reflection of ecological factors that impact the ovaries. However, preliminary evidence and literature from populations of different reproductive states, ages and pathologies also suggests that ecological stress plays a role in endometrial variation, different from or even independent of ovarian function. Immune stress and psychosocial stress appear to play some role in the endometrium's ability to carry a fetus through the mechanism of inflammation. Thus, within reproductive ecology we should move towards a model of women's fecundity and fertility that includes many components of ecological stress and their effects not only on the ovaries, but on processes related to endometrial function. Greater attention on the endometrium may aid in unraveling several issues in hominoid and specifically human evolutionary biology: a low implantation rate, high rates of early pregnancy loss, prenatal investment in singletons but postnatal support of several dependent offspring at once, and higher rate of reproductive and pregnancy-related pathology compared to other primates, ranging from endometriosis to preeclampsia. The study of the endometrium may also complicate some of these issues, as it raises the question of why humans have a maximally invasive placentation method and yet slow fetal growth rates. In this review, I will describe endometrial physiology, methods of measurement, variation, and some of the ecological variables that likely produce variation and pregnancy losses to demonstrate the necessity of further study. I propose several basic avenues of study that leave room for testable hypotheses in the field of reproductive ecology. And finally, I describe the potential of this work not just in reproductive ecology, but in the resolution of broader women's health issues.

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.

Clomiphene citrate or aromatase inhibitors combined with gonadotropins for superovulation in women undergoing intrauterine insemination: a prospective randomised trial

The objective of this study was to test the use of letrozole in combination with follicle-stimulating hormone (FSH) vs clomiphene citrate (CC) with FSH for ovarian hyperstimulation prior to intrauterine insemination (IUI). A prospective randomised trial in which 280 women with unexplained infertility were randomised to 100 mg of CC (141 patients, 219 cycles) or 5 mg of letrozole daily (139 patients, 215 cycles) for 5 days starting on day 3 of menses both combined with gonadotropins for ovarian stimulation prior to IUI. The primary outcome measures were the number of growing and mature follicles, the concentrations of serum E2 (pg/ml) and progesterone (ng/ml), and the endometrial thickness (mm). The secondary outcome measure was the occurrence of pregnancy and miscarriage. The total number of follicles was significantly greater in the CC group (4.1 +/- 0.46 vs 2.6 +/- 0.43). There was no significant difference in endometrial thickness between the two groups. Pregnancy occurred in 33 out of 139 patients (215 cycles) in the letrozole group (23.7% and 15.3%, respectively) and 37 out of 141 patients (219 cycles) (26.2% and 16.8%, respectively) in the CC group; the differences were not statistically significant. The allied use of either CC or letrozole, during ovarian stimulation to reduce the dose of gonadotropins prior to IUI is justified. This approach will reduce the cost of stimulation protocols without effect on the treatment outcome and letrozole has no advantage over CC in this respect.

RETRACTED: Clomiphene citrate or aromatase inhibitors for superovulation in women with unexplained infertility undergoing intrauterine insemination: a prospective randomized trial

This article has been retracted: please see Elsevier Policy on Article Withdrawal (https://www.elsevier.com/about/our-business/policies/article-withdrawal). This article has been retracted at the request of the ASRM Publication Committee Several reports of randomized clinical trials were recently the subject of an investigation conducted by the publications committee of the ASRM. The committee reviewed concerns related to the validity of data reported in those reports. The committee noted significant duplication of data reported in this manuscript with data reported in another journal (PMID: 17582406; https://doi.org/10.1016/j.fertnstert.2007.02.062) pertaining to a different study group that could not be explained. As we cannot vouch for the validity of the data, we have issued a retraction of this paper.

Effects of metformin and clomiphene citrate on ovarian vascularity in patients with polycystic ovary syndrome

OBJECTIVE

To evaluate the effects of metformin and of clomiphene citrate (CC) on the ovarian blood perfusion and on perifollicular and peri-corpus luteum (CL) vascularity in anovulatory women with polycystic ovary syndrome (PCOS).

DESIGN

Prospective cohort study.

SETTING

University "Magna Graecia" of Catanzaro.

PATIENT(S)

Forty anovulatory nonobese patients with PCOS who ovulated under treatment with metformin (850 mg twice daily) plus placebo (metformin group) and 38 under placebo plus CC (150 mg for 5 days; CC group). Another 30 healthy normal cycled women (control group).

INTERVENTION(S)

Serial transvaginal ultrasonographic examinations.

MAIN OUTCOME MEASURE(S)

Ovary artery blood flow impedance, dimensions, and vascularization of the dominant follicle and of the CL.

RESULT(S)

No difference was observed in all parameters in metformin ovulating cycles in comparison with healthy controls. In CC ovulating cycles, ovarian artery impedance, and perifollicular and peri-CL vascularization the results were significantly different from the metformin and control groups. After grouping the stimulated cycles for reproductive outcomes, perifollicular vascularization alone ended up being significantly lower only in CC-stimulated cycles with unfavorable outcome.

CONCLUSION(S)

In patients with PCOS who ovulate under treatment with metformin, the ovarian blood flows are similar to those observed in healthy women, whereas CC administration reduces the ovarian and, specifically, the perifollicular vascularization.

The human endometrium as a fertility-determining factor

Intensive research work has been performed to better understand the regulation of the endometrium and its clinical implications to improve implantation. Although many proteins and molecules may influence endometrial development, their co-ordinated contribution to the implantation process is still poorly understood and a translation into clinical use has not sufficiently been performed. Clinical evaluation of the endometrium by ultrasound and other techniques, like endometrial biopsy and analysis of uterine secretions, has been intensively studied and therapeutic options to improve endometrial function have been suggested and tested. Systemic treatment with heparin, aspirin or corticosteroids did not result in improved implantation rates. Gene therapy and cervical treatment, e.g. with seminal plasma, are still in the phase of clinical research. Therefore, this review focuses on different aspects of endometrial research, which all contribute to the diagnosis, evaluation and therapy of endometrial function and dysfunction. First, the endometrial development towards a receptive milieu is described. Second, the actual clinical evaluation of endometrial receptivity, possible therapeutic strategies and in particular, the evaluation of endometrial function in the non-natural situation of hormonal stimulation is critically evaluated. In conclusion, the endometrium shall be considered as an important fertility-determining factor and therapeutic options should be developed in near future.

Comparison of outcome of clomiphene citrate/human menopausal gonadotropin/cetrorelix protocol and buserelin long protocol--a randomized study

This study evaluates the efficacy of a stimulation protocol with clomiphene citrate (CC)/human menopausal gonadotropin (hMG)/cetrorelix and its effects on oocyte quality and endometrium. One hundred and twenty couples with male-factor infertility who were about to undergo their first intracytoplasmic sperm injection cycles were randomized into two groups. Sixty women were stimulated with the CC/hMG/cetrorelix protocol (cetrorelix group) and 60 received the buserelin long protocol (buserelin group). Fewer oocytes were recovered in the cetrorelix group than in the buserelin group (mean +/- standard deviation (SD): 11.1 +/- 4.0 vs. 17.3 +/- 5.8, p < 0.001); however, the percentages of metaphase II, metaphase I and germinal vesicle oocytes were similar between the two groups. Serum estradiol level was significantly lower in the cetrorelix than in the buserelin group (mean +/- SD: 2600.58 +/- 1189.11 vs. 3293.46 +/- 1221.49 pg/ml, p = 0.006), but the endometrial thickness was similar. The implantation rates (19.2% vs. 17.7%) and the pregnancy rates (41.7% vs. 40.0%) were similar between groups. The ampoules (mean +/- SD: 18.9 +/- 3.0 vs. 38.9 +/- 12.2, p < 0.001) and injections (mean +/- SD: 6.8 +/- 1.1 vs. 15.7 +/- 3.1, p < 0.001) of gonadotropin used were significantly lower in the cetrorelix group than in the buserelin group. No patients in either group developed a premature luteinizing hormone surge. The present study found no statistically significant difference between the two treatment modalities with regard to pregnancy rates.

Patient-tailored conventional ovulation induction algorithms in anovulatory infertility

Conventional treatment of normogonadotropic anovulatory infertility is ovulation induction using the antiestrogen clomiphene citrate, followed by follicle-stimulating hormone. Multiple follicle development, associated with ovarian hyperstimulation, and multiple pregnancy remain the major complications. Cumulative singleton and multiple pregnancy rate data after different induction treatments are needed. Newer ovulation induction interventions, such as insulin-sensitizing drugs, aromatase inhibitors and laparoscopic ovarian electrocoagulation, should be compared with conventional strategies. Ovulation induction efficiency might improve if patient subgroups with altered chances for success or complications with new or conventional techniques could be identified, using multivariate prediction models based on initial screening characteristics. This would make ovulation induction more cost-effective, safe and convenient, enabling doctors to advise patients on the most effective and patient-tailored treatment strategy.

High dose of phytoestrogens can reverse the antiestrogenic effects of clomiphene citrate on the endometrium in patients undergoing intrauterine insemination: a randomized trial

OBJECTIVE

To compare the effectiveness of clomiphene citrate (CC) alone or combined with phytoestrogens (PE) in ovulation induction in patients who had intrauterine insemination in a randomized, double-blind study.

METHODS

A total of 134 women aged 25-35 years, who were infertile for at least 2 years and who had oligomenorrhea or amenorrhea associated with a positive menstrual response to the intramuscular progesterone-challenge test were enrolled. They were randomly treated with CC (100 mg daily for 5 days) and CC (100 mg daily for 5 days) in combination with PE (1500 mg daily for 10 days). We estimated the difference in uterine artery pulsatily index, number of preovulatory follicles, endometrial thickness, and pregnancy rate.

RESULTS

Both treatments increased follicle-stimulating hormone, luteinizing hormone, and 17beta-estradiol plasma concentrations, but the differences were not statistically significant. However, the differences in endometrial thickness of the two groups were statistically significant. No significant differences in the pulsatility index values and in the number of preovulatory follicles were noted.

CONCLUSION

A high dose of phytoestrogens can reverse the deleterious effects of clomiphene citrate on endometrial thickness and could contribute to higher pregnancy rates.

Endometrial thickness cannot predict ongoing pregnancy achievement in cycles stimulated with clomiphene citrate for intrauterine insemination

To date, limited data exist concerning the relation between endometrial thickness on the day of human chorionic gonadotrohin (HCG) administration and ongoing pregnancy achievement in cycles stimulated with clomiphene citrate for intrauterine insemination (IUI). In a prospective study, 168 couples were stimulated with clomiphene citrate from day 3 to day 7 of the cycle and endometrial thickness was assessed by ultrasound three times on the day of ovulation triggering. Ovulation was induced with HCG as soon as >/=1 follicle of >/=17 mm was present at ultrasound independently of endometrial thickness. IUI was performed 36 h after HCG administration. The main outcome measure was ongoing pregnancy. No difference was observed in endometrial thickness between patients who did or did not achieve an ongoing pregnancy (7.6 +/- 0.3 versus 7.6 +/- 0.2 respectively; P = 0.7). No discriminative ability of endometrial thickness on the achievement of ongoing pregnancy could be shown by receiver operating characteristic (ROC) curve analysis (area under the ROC curve 0.51, 95% CI: 0.44-0.59). In conclusion, endometrial thickness cannot predict ongoing pregnancy achievement in IUI cycles stimulated with clomiphene citrate.

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.

Effect of clomiphene citrate on endometrium thickness and echogenic patterns

OBJECTIVE

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

METHOD

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

RESULTS

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

CONCLUSION

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

A randomized double-blind comparison of perifollicular vascularity and endometrial receptivity in ovulatory women taking clomiphene citrate at two different times

BACKGROUND

It is still controversial whether the day of clomiphene citrate initiation has any impact on the pregnancy rate. This study aimed to compare the perifollicular vascularity and endometrial receptivity of ovulatory women who started clomiphene citrate on day 2 and day 5.

METHODS

Thirty-five women with regular ovulatory cycles were first monitored in a natural cycle and then randomized by computer-generated random numbers put in sealed opaque envelopes to receive 50 mg clomiphene citrate on days 2-6 or on days 5-9. The hormonal profile, the number of dominant follicles, the grading of perifollicular vascularity, endometrial thickness and Doppler flow indices of uterine/subendometrial arteries were compared between both groups.

RESULTS

All the above parameters were similar for both groups on the day of the LH surge and 7 days after the LH surge.

CONCLUSIONS

There were no differences in oocyte quality graded by the perifollicular vascularity and the endometrial receptivity assessed by endometrial thickness and Doppler flow indices of uterine and subendometrial vessels when clomiphene citrate was started in regularly ovulatory women on day 2 or on day 5.

Ovulation induction

In the woman with anovulation and polycystic ovarian syndrome, there are many options for ovulation induction. Treatment should be individualized, but clomiphene citrate is an excellent first-line agent. In the woman resistant to clomiphene citrate, combination therapy often results in pregnancy. Some women with PCOS only respond to gonadotropin therapy. These women are at a higher risk for multiple pregnancy and ovarian hyperstimulation syndrome. In the woman with anovulation and hypothalamic amenorrhea, the options for ovulation induction are limited. The luteal phase must be supported. The hypothalamus is unable to support the corpus luteum or early pregnancy.

Birth of a western lowland gorilla (Gorilla gorilla gorilla) following in vitro fertilization and embryo transfer

A 21-year-old multiparous female exhibiting 31-41 day menstrual cycles was given hFSH (225 IU/day, Metrodin 75, from cycle day 3 through 9 (menses = day 1) and hCG (10,000 IU, Profasi, on day 10 to stimulate follicular development. At 35 h after hCG, under isoflurane (AErrane) anesthesia, follicles were aspirated by controlled suction under transvaginal ultrasound guidance. Metaphase II oocytes (n = 11) were placed in modified human tubal fluid (mHTF, 100 microliters) medium under oil at 37 degrees C in humidified 5% CO2. Frozen semen, collected by voluntary ejaculation, was thawed (70 degrees C H2O bath, 6 sec), diluted slowly, centrifuged, and resuspended in mHTF, and 160,000 motile spermatozoa/ml were added at 6 h after oocyte recovery. At 21 h postinsemination (p.i.) eight oocytes were at the two-cell stage, five were cryopreserved, and three were cultured to the six- to eight-cell stage in mHTF with granulosa cells before transcervical uterine transfer at 47 h p.i. using a Teflon catheter. Micronized progesterone (400 mg/d) was orally administered for 10 weeks posttransfer (p.t.). Ultrasound examination revealed a single fetus at 15 weeks p.t., and unassisted delivery of a live 1.37 kg female infant occurred at 29 weeks. Am. J. Primatol. 41:247-260, 1997.

TRANSVAGINAL SONOGRAPHIC STUDY OF FOLLICULAR DYNAMICS IN SPONTANEOUS AND CLOMIPHENE CITRATE CYCLES

A study of 186 infertile women was carried out to evaluate the effect of clomiphene citrate on the follicular dynamics. All patients underwent transvaginal sonography over at least 02 consecutive cycles-spontaneous followed by clomiphene stimulated cycle. Clomiphene citrate resulted in higher average follicular diameter on all corresponding days as compared to spontaneous cycles. Multifollicular response was common in clomiphene stimulated cycles.

Effects of clomiphene citrate on the endometrium of regularly cycling women

OBJECTIVE

To study the effects of clomiphene citrate (CC) on the endometrium of regularly cycling women.

DESIGN

Prospective, controlled study.

SETTING

Department of Obstetrics and Gynaecology, Faculty of Medicine, Chulalongkorn University, Bangkok, Thailand.

PATIENT(S)

Thirty healthy, regularly cycling, female volunteers.

INTERVENTION(S)

All volunteers were studied for two consecutive cycles, one control cycle and one CC-treated cycle. Clomiphene citrate (100 mg/d) was given on days 3-7 of the CC-treated cycles. Ultrasonography was performed daily to assess ovulation. Ultrasonography and endometrial biopsy were performed, and blood samples were obtained for determination of E2 and progesterone levels 7 days after ovulation in both the control and CC-treated cycles.

MAIN OUTCOME MEASURE(S)

Histologic dating, morphometric analysis, and ultrasonographic appearance and thickness of the endometrium.

RESULT(S)

Histologic dating and ultrasonographic appearance and thickness of the endometrium were similar in the control and CC-treated cycles, but morphometric parameters were different. The number of glands per square millimeter and the mean diameter of the glands were lower in the CC-treated cycles than in the control cycles, but the number of vacuolated cells per 1,000 glandular cells was higher.

CONCLUSION(S)

Clomiphene citrate has effects on the endometrium of regularly cycling women, as demonstrated by a reduction in glandular density and an increase in the number of vacuolated cells.

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.

Use of ethinyl estradiol to reverse the antiestrogenic effects of clomiphene citrate in patients undergoing intrauterine insemination: a comparative, randomized study

OBJECTIVE

To compare the effectiveness of clomiphene citrate used alone and in combination with ethinyl E2 for the induction of ovulation in patients undergoing IUI.

DESIGN

Randomized, double-blind study.

SETTING

Four infertility treatment centers.

PATIENT(S)

Women aged 25-35 years with infertility of at least 2 years' duration and oligomenorrhea or amenorrhea associated with a positive menstrual response to an IM progesterone challenge.

INTERVENTION(S)

A total of 64 patients were randomized to treatment with CC (100 mg daily for 5 days) or CC (100 mg daily for 5 days) plus ethinyl E2 (0.05 mg daily for 5 days).

MAIN OUTCOME MEASURE(S)

The uterine artery pulsatility index, number of preovulatory follicles, endometrial thickness, and pregnancy rate.

RESULT(S)

Both treatment regimens increased FSH, LH, and 17beta-E2 levels, with no statistically significant differences. There was a statistically significant difference in endometrial thickness between the two treatment groups. No statistically significant differences were noted in pulsatility index values or in the number of preovulatory follicles.

CONCLUSION(S)

Ethinyl E2 can reverse the deleterious effects of CC on endometrial thickness, which may contribute to higher pregnancy rates.