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

Long-term outcomes of switching to gonadotrophins versus continuing with clomiphene citrate, with or without intrauterine insemination, in women with normogonadotropic anovulation and clomiphene failure: follow-up study of a factorial randomized clinical trial

STUDY QUESTION

What are the long-term outcomes after allocation to use of gonadotrophins versus clomiphene citrate (CC) with or without IUI in women with normogonadotropic anovulation and clomiphene failure?

SUMMARY ANSWER

About four in five women with normogonadotropic anovulation and CC failure had a live birth, with no evidence of a difference in pregnancy outcomes between the allocated groups.

WHAT IS KNOWN ALREADY

CC has long been used as first line treatment for ovulation induction in women with normogonadotropic anovulation. Between 2009 and 2015, a two-by-two factorial multicentre randomized clinical trial in 666 women with normogonadotropic anovulation and six cycles of CC failure was performed (M-ovin trial). This study compared a switch to gonadotrophins with continued treatment with CC for another six cycles, with or without IUI within 8 months. Switching to gonadotrophins increased the chance of conception leading to live birth by 11% over continued treatment with CC after six failed ovulatory cycles, at a cost of €15 258 per additional live birth. The addition of IUI did not significantly increase live birth rates.

STUDY DESIGN, SIZE, DURATION

In order to investigate the long-term outcomes of switching to gonadotrophins versus continuing treatment with CC, and undergoing IUI versus continuing with intercourse, we conducted a follow-up study. The study population comprised all women who participated in the M-ovin trial.

PARTICIPANTS/MATERIALS, SETTING, METHODS

The participating women were asked to complete a web-based questionnaire. The primary outcome of this study was cumulative live birth. Secondary outcomes included clinical pregnancies, multiple pregnancies, miscarriage, stillbirth, ectopic pregnancy, fertility treatments, neonatal outcomes and pregnancy complications.

MAIN RESULTS AND THE ROLE OF CHANCE

We approached 564 women (85%), of whom 374 (66%) responded (184 allocated to gonadotrophins; 190 to CC). After a median follow-up time of 8 years, 154 women in the gonadotrophin group had a live birth (83.7%) versus 150 women in the CC group (78.9%) (relative risk (RR) 1.06, 95% CI 0.96-1.17). A second live birth occurred in 85 of 184 women (49.0%) in the gonadotrophin group and in 85 of 190 women (44.7%) in the CC group (RR 1.03, 95% CI 0.83-1.29). Women allocated to gonadotrophins had a third live birth in 6 of 184 women (3.3%) and women allocated to CC had a third live birth in 14 of 190 women (7.4%). There were respectively 12 and 11 twins in the gonadotrophin and CC groups. The use of fertility treatments in the follow-up period was comparable between both groups. In the IUI group, a first live birth occurred in 158 of 192 women (82.3%) and while in the intercourse group, 146 of 182 women (80.2%) reached at least one live birth (RR: 1.03 95% CI 0.93-1.13; 2.13%, 95% CI -5.95, 10.21).

LIMITATIONS, REASONS FOR CAUTION

We have complete follow-up results for 57% of the women.There were 185 women who did not respond to the questionnaire, while 102 women had not been approached due to missing contact details. Five women had not started the original trial.

WIDER IMPLICATIONS OF THE FINDINGS

Women with normogonadotropic anovulation and CC failure have a high chance of reaching at least one live birth. In terms of pregnancy rates, the long-term differences between initially switching to gonadotrophins are small compared to continuing treatment with CC.

STUDY FUNDING/COMPETING INTEREST(S)

The original study received funding from the Dutch Organization for Health Research and Development (ZonMw number: 80-82310-97-12067). A.H. reports consultancy for development and implementation of a lifestyle App, MyFertiCoach, developed by Ferring Pharmaceutical Company. M.G. receives unrestricted grants for scientific research and education from Ferring, Merck and Guerbet. B.W.M. is supported by an NHMRC Investigatorgrant (GNT1176437). B.W.M. reports consultancy for ObsEva and Merck and travel support from Merck. All other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

This follow-up study was registered in the OSF Register, https://osf.io/pf24m. The original M-ovin trial was registered in the Netherlands Trial Register, number NTR1449.

Gonadotrophins or clomiphene citrate in women with normogonadotropic anovulation and CC failure: does the endometrium matter?

STUDY QUESTION

Is endometrial thickness (EMT) a biomarker to select between women who should switch to gonadotropins and those who could continue clomiphene citrate (CC) after six failed ovulatory cycles?

SUMMARY ANSWER

Using a cut-off of 7 mm for EMT, we can distinguish between women who are better off switching to gonadotropins and those who could continue CC after six earlier failed ovulatory CC cycles.

WHAT IS ALREADY KNOWN

For women with normogonadotropic anovulation, CC has been a long-standing first-line treatment in conjunction with intercourse or intrauterine insemination (IUI). We recently showed that a switch to gonadotropins increases the chance of live birth by 11% in these women over continued treatment with CC after six failed ovulatory cycles, at a cost of €15 258 per additional live birth. It is unclear whether EMT can be used to identify women who can continue on CC with similar live birth rates without the extra costs of gonadotropins.

STUDY DESIGN, SIZE, DURATION

Between 8 December 2008 and 16 December 2015, 666 women with CC failure were randomly assigned to receive an additional six cycles with a change to gonadotropins (n = 331) or an additional six cycles continuing with CC (n = 335), both in conjunction with intercourse or IUI. The primary outcome was conception leading to live birth within 8 months after randomisation. EMT was measured mid-cycle before randomisation during their sixth ovulatory CC cycle. The EMT was available in 380 women, of whom 190 were allocated to gonadotropins and 190 were allocated to CC.

PARTICIPANTS/MATERIALS, SETTING, METHODS

EMT was determined in the sixth CC cycle prior to randomisation. We tested for interaction of EMT with the treatment effect using logistic regression. We performed a spline analysis to evaluate the association of EMT with chance to pregnancy leading to a live birth in the next cycles and to determine the best cut-off point. On the basis of the resulting cut-off point, we calculated the relative risk and 95% CI of live birth for gonadotropins versus CC at EMT values below and above this cut-off point. Finally, we calculated incremental cost-effectiveness ratios (ICER).

MAIN RESULTS AND THE ROLE OF CHANCE

Mid-cycle EMT in the sixth cycle interacted with treatment effect (P < 0.01). Spline analyses showed a cut-off point of 7 mm. There were 162 women (45%) who had an EMT ≤ 7 mm in the sixth ovulatory cycle and 218 women (55%) who had an EMT > 7 mm. Among the women with EMT ≤ 7 mm, gonadotropins resulted in a live birth in 44 of 79 women (56%), while CC resulted in a live birth in 28 of 83 women (34%) (RR 1.57, 95% CI 1.13–2.19). Per additional live birth with gonadotropins, the ICER was €9709 (95% CI: €5117 to €25 302). Among the women with EMT > 7 mm, gonadotropins resulted in a live birth in 53 of 111 women (48%) while CC resulted in a live birth in 52 of 107 women (49%) (RR 0.98, 95% CI 0.75–1.29).

LIMITATIONS, REASONS FOR CAUTION

This was a post hoc analysis of a randomised controlled trial (RCT) and therefore mid-cycle EMT measurements before randomisation during their sixth ovulatory CC cycle were not available for all included women.

WIDER IMPLICATIONS OF THE FINDINGS

In women with six failed ovulatory cycles on CC and an EMT ≤ 7 mm in the sixth cycle, we advise switching to gonadotropins, since it improves live birth rate over continuing treatment with CC at an extra cost of €9709 to achieve one additional live birth. If the EMT > 7 mm, we advise to continue treatment with CC, since live birth rates are similar to those with gonadotropins, without the extra costs.

STUDY FUNDING/COMPETING INTEREST(S)

The original MOVIN trial received funding from the Dutch Organization for Health Research and Development (ZonMw number: 80-82310-97-12067). C.B.L.A. reports unrestricted grant support from Merck and Ferring. B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548) and reports consultancy for Merck, ObsEva, IGENOMIX and Guerbet. All other authors have nothing to declare.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register, number NTR1449

Gonadotrophins versus clomiphene citrate with or without IUI in women with normogonadotropic anovulation and clomiphene failure: a cost-effectiveness analysis

STUDY QUESTION

Are six cycles of ovulation induction with gonadotrophins more cost-effective than six cycles of ovulation induction with clomiphene citrate (CC) with or without IUI in normogonadotropic anovulatory women not pregnant after six ovulatory cycles with CC?

SUMMARY ANSWER

Both gonadotrophins and IUI are more expensive when compared with CC and intercourse, and gonadotrophins are more effective than CC.

WHAT IS KNOWN ALREADY

In women with normogonadotropic anovulation who ovulate but do not conceive after six cycles with CC, medication is usually switched to gonadotrophins, with or without IUI. The cost-effectiveness of these changes in policy is unknown.

STUDY DESIGN, SIZE, DURATION

We performed an economic evaluation of ovulation induction with gonadotrophins compared with CC with or without IUI in a two-by-two factorial multicentre randomized controlled trial in normogonadotropic anovulatory women not pregnant after six ovulatory cycles with CC. Between December 2008 and December 2015 women were allocated to six cycles with gonadotrophins plus IUI, six cycles with gonadotrophins plus intercourse, six cycles with CC plus IUI or six cycles with CC plus intercourse. The primary outcome was conception leading to a live birth achieved within 8 months of randomization.

PARTICIPANTS/MATERIALS, SETTING, METHODS

We performed a cost-effectiveness analysis on direct medical costs. We calculated the direct medical costs of ovulation induction with gonadotrophins versus CC and of IUI versus intercourse in six subsequent cycles. We included costs of medication, cycle monitoring, interventions, and pregnancy leading to live birth. Resource use was collected from the case report forms and unit costs were derived from various sources. We calculated incremental cost-effectiveness ratios (ICER) for gonadotrophins compared to CC and for IUI compared to intercourse. We used non-parametric bootstrap resampling to investigate the effect of uncertainty in our estimates. The analysis was performed according to the intention-to-treat principle.

MAIN RESULTS AND THE ROLE OF CHANCE

We allocated 666 women in total to gonadotrophins and IUI (n = 166), gonadotrophins and intercourse (n = 165), CC and IUI (n = 163), or CC and intercourse (n = 172). Mean direct medical costs per woman receiving gonadotrophins or CC were €4495 versus €3006 (cost difference of €1475 (95% CI: €1457-€1493)). Live birth rates were 52% in women allocated to gonadotrophins and 41% in those allocated to CC (relative risk (RR) 1.24:95% CI: 1.05-1.46). The ICER was €15 258 (95% CI: €8721 to €63 654) per additional live birth with gonadotrophins. Mean direct medical costs per woman allocated to IUI or intercourse were €4497 versus €3005 (cost difference of €1510 (95% CI: €1492-€1529)). Live birth rates were 49% in women allocated to IUI and 43% in those allocated to intercourse (RR = 1.14:95% CI: 0.97-1.35). The ICER was €24 361 (95% CI: €-11 290 to €85 172) per additional live birth with IUI.

LIMITATIONS, REASONS FOR CAUTION

We allowed participating hospitals to use their local protocols for ovulation induction and IUI, which may have led to variation in costs, but which increases generalizability. Indirect costs generated by transportation or productivity loss were not included. We did not evaluate letrozole, which is potentially more effective than CC.

WIDER IMPLICATIONS OF THE FINDINGS

Gonadotrophins are more effective, but more expensive than CC, therefore, the use of gonadotrophins in women with normogonadotropic anovulation who have not conceived after six ovulatory CC cycles depends on society's willingness to pay for an additional child. In view of the uncertainty around the cost-effectiveness estimate of IUI, these data are not sufficient to make recommendations on the use of IUI in these women. In countries where ovulation induction regimens are reimbursed, policy makers and health care professionals may use our results in their guidelines.

STUDY FUNDING/COMPETING INTEREST(S)

This trial was funded by the Netherlands Organization for Health Research and Development (ZonMw number: 80-82310-97-12067). The Eudract number for this trial is 2008-006171-73. The Sponsor's Protocol Code Number is P08-40. CBLA reports unrestricted grant support from Merck and Ferring. BWM is supported by a NHMRC Practitioner Fellowship (GNT1082548) and reports consultancy for Merck, ObsEva and Guerbet.

TRIAL REGISTRATION NUMBER

NTR1449.

Gonadotrophins versus clomifene citrate with or without intrauterine insemination in women with normogonadotropic anovulation and clomifene failure (M-OVIN): a randomised, two-by-two factorial trial

BACKGROUND

In many countries, clomifene citrate is the treatment of first choice in women with normogonadotropic anovulation (ie, absent or irregular ovulation). If these women ovulate but do not conceive after several cycles with clomifene citrate, medication is usually switched to gonadotrophins, with or without intrauterine insemination. We aimed to assess whether switching to gonadotrophins is more effective than continuing clomifene citrate, and whether intrauterine insemination is more effective than intercourse.

METHODS

In this two-by-two factorial multicentre randomised clinical trial, we recruited women aged 18 years and older with normogonadotropic anovulation not pregnant after six ovulatory cycles of clomifene citrate (maximum of 150 mg daily for 5 days) from 48 Dutch hospitals. Women were randomly assigned using a central password-protected internet-based randomisation programme to receive six cycles with gonadotrophins plus intrauterine insemination, six cycles with gonadotrophins plus intercourse, six cycles with clomifene citrate plus intrauterine insemination, or six cycles with clomifene citrate plus intercourse. Clomifene citrate dosages varied from 50 to 150 mg daily orally and gonadotrophin starting dose was 50 or 75 IU daily subcutaneously. The primary outcome was conception leading to livebirth within 8 months after randomisation defined as any baby born alive after a gestational age beyond 24 weeks. Primary analysis was by intention to treat. We made two comparisons, one in which gonadotrophins were compared with clomifene citrate and one in which intrauterine insemination was compared with intercourse. This completed study is registered with the Netherlands Trial Register, number NTR1449.

FINDINGS

Between Dec 8, 2008, and Dec 16, 2015, we randomly assigned 666 women to gonadotrophins and intrauterine insemination (n=166), gonadotrophins and intercourse (n=165), clomifene citrate and intrauterine insemination (n=163), or clomifene citrate and intercourse (n=172). Women allocated to gonadotrophins had more livebirths than those allocated to clomifene citrate (167 [52%] of 327 women vs 138 [41%] of 334 women, relative risk [RR] 1·24 [95% CI 1·05-1·46]; p=0·0124). Addition of intrauterine insemination did not increase livebirths compared with intercourse (161 [49%] vs 144 [43%], RR 1·14 [95% CI 0·97-1·35]; p=0·1152). Multiple pregnancy rates for the two comparisons were low and not different. There were three adverse events: one child with congenital abnormalities and one stillbirth in two women treated with clomifene citrate, and one immature delivery due to cervical insufficiency in a woman treated with gonadotrophins.

INTERPRETATION

In women with normogonadotropic anovulation and clomifene citrate failure, a switch of treatment to gonadotrophins increased the chance of livebirth over treatment with clomifene citrate; there was no evidence that addition of intrauterine insemination does so.

FUNDING

The Netherlands Organization for Health Research and Development.

Women's perspectives on ovulation induction with or without IUI as treatment for normogonadotrophic anovulation: a discrete choice experiment

Study Question

What are the treatment preferences of women with normogonadotrophic anovulation treated with ovulation induction with or without intrauterine insemination (IUI)?

Summary Answer

Women with normogonadotrophic anovulation differ in their treatment preference; half of them base their preference on the lowest burden and half of them on the highest effectiveness.

What is Known Already

Common treatments for anovulatory women who wish to conceive are ovulation induction using clomiphene citrate or letrozole taken in tablet form or with injections containing gonadotrophins, all optionally combined with IUI. Patient preferences for these alternatives have not yet been examined in these women.

Study Design, Size, and Duration

Between August 2014 and February 2017 we conducted a multicentre discrete choice experiment (DCE). The target sample size was calculated by including 20 women for six attributes in the main analysis resulting in the inclusion of 120 women to be able to assess heterogeneity across choices.

Participants/Materials, Setting, Methods

We invited treatment-naive women diagnosed with normogonadotropic anovulation and visiting the outpatient clinic of five Dutch centers (three teaching hospitals and two university hospitals) to participate in the DCE by completing a printed questionnaire. We asked women to indicate their preference in hypothetical alternative treatment scenarios by offering a series of choice sets from which they were to choose their preferred alternatives. The choice sets contained several treatment characteristics of interest, i.e. attributes concerning ovulation induction with clomiphene citrate or letrozole versus gonadotrophins, as well as intercourse and IUI. We selected six attributes: number of visits to the outpatient clinic during treatment; type of medication; intercourse or IUI; risk of side effects; willingness to pay; and pregnancy chances leading to the birth of a child after six treatment cycles.

We used a multinominal logit model to determine the preferences of women and investigated heterogeneity in preferences through latent class analysis. To determine if women were willing to make a trade-off for higher pregnancy rates at the expense of a higher burden, we calculated the marginal rate of substitution.

Main Results and the Role of Chance

The questionnaire was completed by 145 women. All six attributes influenced women’s treatment preferences and those valued as most important were low risk of side effects, a minimal number of hospital visits and intercourse. A total of 55% of women were driven by the wish to conceive with the least medical interference and lowest burden. The remaining women were success driven and chose mainly for the highest chances to conceive, regardless of the burden. Age and duration of subfertility did not significantly differ between these women. Women were willing to trade-off some burden and costs for higher pregnancy chances.

Limitations Reasons for Caution

The sample size of our study is relatively small which made it not possible to perform interaction tests and subgroup analyses.

Wider Implications of the Findings

Our results may be used during the counseling of couples about their treatment options. These findings are an argument to explore if a woman prefers potentially fast success or a medically less intense route that might take longer. The preference for the less intense route would lead to the continuation of ovulation induction with oral drugs such as clomiphene citrate or letrozole rather than treatment with injected gonadotrophins, or even IVF.

Study Funding/Competing Interest(s)

B.W.M. is supported by a NHMRC Practitioner Fellowship (GNT1082548). B.W.M. reports consultancy for Merck, ObsEva and Guerbet. CBL reports grants from Merck and Ferring.

Trial Registration Number

None.

Luteal phase clomiphene citrate for ovulation induction in women with polycystic ovary syndrome: a systematic review and meta-analysis

OBJECTIVE

To assess the efficacy of late luteal phase clomiphene citrate (CC) administration relative to early follicular phase CC for ovulation induction for polycystic ovary syndrome (PCOS).

STUDY DESIGN

Review.

MATERIALS AND METHODS

A complete electronic databases including PubMed, Embase, The Cochrane Library, Web of Science, and CBM were searched for relevant randomized controlled trials (RCTs). The search was not restricted by language and publication time. Two reviewers selected trials and assessed trial quality by the Cochrane Handbook 5.1.0 independently.

RESULTS

Four eligible RCT studies involving 708 women (934 cycles) were included. The results of the Meta-analysis: Late luteal phase group was associated with a number of higher total follicles (MD 1.82; 95% CI 0.86-2.78, p < 0.00001) and significant higher endometrial thickness on the day of HCG (MD 0.88; 95% CI 0.78-0.99, p < 0.00001) compared with early follicular group. There were no significant differences in the rate of pregnancy (RR 1.29; 95% CI 0.83-2.01, p = 0.26), ovulation rate (RR 0.99; 95% CI 0.86-1.14, p = 0.87), and abortion rate (RR 1.12; 95% CI 0.38 to 3.29, p = 0.84) between the two groups.

CONCLUSION

It appeared that late luteal phase CC for ovulation induction might be an effective method for ovulation induction in women with PCOS compared to conventional CC administration. Further intensive randomized-controlled studies should be warranted to define the efficacy of CC used in late luteal phase.

Mono-ovulation in women with polycystic ovary syndrome: a clinical review on ovulation induction

Polycystic ovary syndrome (PCOS) affects 5-10% of women of reproductive age and is the most common cause of anovulatory infertility. The treatment approaches to ovulation induction vary in efficacy, treatment duration and patient friendliness. The aim was to determine the most efficient, evidence-based method to achieve mono-ovulation in women diagnosed with PCOS. Publications in English providing information on treatment, efficacy and complication rates were included until September 2015. Systematic reviews, meta-analyses and randomized controlled trials were favoured over cohort and retrospective studies. Clomiphene citrate is recommended as primary treatment for PCOS-related infertility. It induces ovulation in three out of four patients, the risk of multiple pregnancies is modest and the treatment is simple and inexpensive. Gonadotrophins are highly efficient in a low-dose step-up regimen. Ovulation rates are improved by lifestyle interventions in overweight women. Metformin may improve the menstrual cycle within 1-3 months, but does not improve the live birth rate. Letrozole is effective for ovulation induction, but is an off-label drug in many countries. Ovulation induction in women with PCOS should be individualized with regard to weight, treatment efficacy and patient preferences with the aim of achieving mono-ovulation and subsequently the birth of a singleton baby.

Recombinant FSH Compared to Clomiphene Citrate as the First-Line in Ovulation Induction in Polycystic Ovary Syndrome Using Newly Designed Pens: A Randomized Controlled Trial

OBJECTIVE

Since there is still controversy regarding the best first-line choice for ovulation induction (OI) other than clomiphene citrate (CC) in infertile women diagnosed with polycystic ovary syndrome (PCOS), the aim of the present study was to compare recombinant human FSH with CC as the first course of OI in these women.

MATERIALS AND METHODS

In this pilot randomized controlled trial, 104 infertile women diagnosed with PCOS were randomized in two groups to receive either CC with the dose of 100mg per day from day 3 of a spontaneous or progestin-induced menstruation for 5 days or rFSH with the starting dose of 50 IU daily {and weekly dose increment of as low as 12.5 IU}, on the day4 of the cycle. They were assessed during a single OI course. The pregnancy rate (PR) and live birth rate (LBR) were the primary outcomes. The follicular response, endometrial thickness, cancellation of the cycles and ovarian hyper stimulation (OHSS) rate were the secondary outcomes.

RESULTS

Analyzing data of 96 patients using Chi(2) and Fischer's Exact test (44 in rFSH group and 52 in CC group), both PR and LBR were comparable in the two groups {13.6% vs. 9.6% and 11.4% vs. 9.6% respectively}, with the difference not to be significant (p > 0.05). No cases of OHSS or multiple gestations happened during the treatment course.

CONCLUSION

It seems that rFSH is as efficacious as CC while not with more complications for the first-line OI in infertile women with PCOS. However, due to the limitations of the present study including the small population and the single cycle of treatment, our results did not come out to prove this and more studies with larger study population are needed to compare the cumulative PR and LBR.

How long should we continue clomiphene citrate in anovulatory women?

STUDY QUESTION

What is the effectiveness of continued treatment with clomiphene citrate (CC) in women with World Health Organization (WHO) type II anovulation who have had at least six ovulatory cycles with CC but did not conceive?

SUMMARY ANSWER

When women continued CC after six treatment cycles, the cumulative incidence rate of the ongoing pregnancy rate was 54% (95% CI 37-78%) for cycles 7-12.

WHAT IS KNOWN ALREADY

If women with WHO type II anovulation fail to conceive with CC within six ovulatory cycles, guidelines advise switching to gonadotrophins, which have a high risk of multiple gestation and are expensive. It is however not clear what success rate could be achieved by continued treatment with CC.

STUDY DESIGN, SIZE, DURATION

We performed a retrospective cohort study of women with WHO II anovulation who visited the fertility clinics of five hospitals in the Netherlands between 1994 and 2010. We included women treated with CC who had had at least six ovulatory cycles without successful conception (n = 114) after which CC was continued using dosages varying from 50 to 150 mg per day for 5 days.

PARTICIPANTS/MATERIALS, SETTING, METHODS

Follow-up was a total of 12 treatment cycles. Primary outcome was the cumulative incidence rate of an ongoing pregnancy at the end of treatment.

MAIN RESULTS AND THE ROLE OF CHANCE

We recruited 114 women that had ovulated on CC for at least six cycles but had not conceived. Of these 114 women, 35 (31%) had an ongoing pregnancy resulting in a cumulative incidence rate of an ongoing pregnancy of 54% after 7-12 treatment cycles with CC.

LIMITATIONS, REASONS FOR CAUTION

Limitations of our study are its retrospective approach.

WIDER IMPLICATIONS OF THE FINDINGS

Randomized trials comparing continued treatment with CC with the relatively established second line treatment with gonadotrophins are justified. In the meantime, we suggest to only begin this less convenient and more expensive treatment for women who do not conceive after 12 ovulatory cycles with CC.

STUDY FUNDING/COMPETING INTERESTS

None.

TRIAL REGISTRATION NUMBER

Not applicable.