The effect of dietary interventions on pain and quality of life in women diagnosed with endometriosis: a prospective study with control group.

STUDY QUESTION: What is the influence of dietary interventions, namely the low fermentable oligo-, di-, mono-saccharides, and polyols (Low FODMAP) diet and endometriosis diet, on endometriosis-related pain and quality of life (QoL) compared to a control group? SUMMARY ANSWER: After adhering to a dietary intervention for 6 months, women with endometriosis reported less pain and an improved QoL compared to baseline whereas, compared to the control group, they reported less bloating and a better QoL in 3 of 11 domains. WHAT IS KNOWN ALREADY: Standard endometriosis treatment can be insufficient or may be accompanied by unacceptable side effects. This has resulted in an increasing interest in self-management strategies, including the appliance of the Low FODMAP diet and the endometriosis diet (an experience-based avoidance diet, developed by women with endometriosis). The Low FODMAP diet has previously been found effective in reducing endometriosis-related pain symptoms, whereas only limited studies are available on the efficacy of the endometriosis diet. A survey study recently found the endometriosis diet effective in improving QoL but currently no guidelines on use of the diet exist. STUDY DESIGN, SIZE, DURATION: A prospective one-center pilot study was performed between April 2021 and December 2022. Participants could choose between adherence to a diet-the Low FODMAP diet or endometriosis diet-or no diet (control group). Women adhering to a diet received extensive guidance from a dietician in training. The follow-up period was 6 months for all three groups. For all outcomes, women adhering to the diets were compared to their baseline situation and to the control group. PARTICIPANTS/MATERIALS, SETTING, METHODS: We included women diagnosed with endometriosis (surgically and/or by radiologic imaging) who reported pain scores ≥3 cm on the visual analogue score (0-10 cm) for dysmenorrhea, deep dyspareunia, and/or chronic pelvic pain. The primary endpoint focused on pain reduction for all pain symptoms, including dysuria, bloating, and tiredness. Secondary endpoints, assessed via questionnaires, focused on QoL, gastro-intestinal health, and diet adherence. MAIN RESULTS AND THE ROLE OF CHANCE: A total of 62 participants were included in the low FODMAP diet (n = 22), endometriosis diet (n = 21), and control group (n = 19). Compared to their baseline pain scores, participants adhering to a diet reported less pain in four of six symptoms (range P < 0.001 to P = 0.012) and better scores in 6 of 11 QoL domains (range P < 0.001 to P = 0.023) after 6 months. Compared to the control group, analyzed longitudinally over the 6-month follow-up period, participants applying a diet reported significant less bloating (P = 0.049), and better scores in 3 of 11 QoL domains (range P = 0.002 to P = 0.035). LIMITATIONS, REASONS FOR CAUTION: No sample size was calculated since efficacy data were lacking in the literature. In order to optimize dietary adherence, randomization was not applied, possibly resulting in selection bias. WIDER IMPLICATIONS OF THE FINDINGS: Our study suggests that women could benefit from adherence to a dietary intervention, since we found lower pain scores and better QoL after 6 months. However, caution is implied since this is a pilot study, no sample size was calculated, and data on long-term effects (>6 months) are lacking. The results of this pilot study underline the importance of further research and the drawing up of guidelines. STUDY FUNDING/COMPETING INTEREST(S): A.v.H. reports receiving a travel grant from Merck outside the scope of this study. J.W., S.V., J.T., and B.D.B. have no conflicts of interest to report. A.d.V. reports having received KP-register points for internship guidance of J.W., performing paid consultations with endometriosis patients outside the study and receiving reimbursements for educational lectures at the local hospital (Albert Schweitzer Ziekenhuis, Dordrecht, the Netherlands). A.S. reports having received expenses for travel and hotel costs as an invited speaker from ESHRE. This was outside the scope of this study. M.v.W. reports that she is a Co-Ed of Cochrane Gynecology and Fertility. V.M. reports receiving travel and speaker's fees from Guerbet and research grants from Guerbet, Merck and Ferring. The department of reproductive medicine (V.M.) of the Amsterdam UMC, location VUmc, has received several research and educational grants from Guerbet, Merck and Ferring not related to the submitted work. TRIAL REGISTRATION NUMBER: N/A.

Deep endometriosis muscular infiltration of the bowel wall: correlation between MRI and histopathology.

AIM: To assess the correlation between magnetic resonance imaging (MRI) and histopathology for predicting muscular infiltration of endometriosis in the bowel wall in patients undergoing colorectal resection. MATERIALS AND METHODS: All consecutive patients who underwent colorectal surgery for deep endometriosis (DE) with a preoperative MRI in a single tertiary care referral hospital between 2001 and 2019 were included in a prospective cohort. MRI images were revised by a single blinded radiologist. The MRI results regarding the infiltration depth (serosal, muscular, submucosal, or mucosal) and lesion expansion of DE were compared to histopathology. RESULTS: A total of 84 patients were eligible for evaluation. A sensitivity of 89% and positive predictive value of 97% was shown for predicting muscular involvement of the bowel wall. CONCLUSION: This study showed that MRI is valuable in predicting the involvement of the muscular layer of the colorectal wall. Therefore, in patients with symptomatic pelvic bowel endometriosis MRI is a useful tool in guiding the extent of colorectal surgery.

A systematic review and secondary analysis of two studies identifying demographic and medical characteristics determining patient-centeredness in endometriosis care as experienced by patients.

STUDY QUESTION: What are the patient-specific determinants associated with patient-centered endometriosis care as measured by the ENDOCARE questionnaire (ECQ)? SUMMARY ANSWER: 'Overall grade for endometriosis care', 'educational level', 'membership of a patient organization' and 'having seen other specialists for endometriosis complaints' are correlated with overall patient-centeredness scores (PCS). WHAT IS KNOWN ALREADY: Patient-centeredness of endometriosis care can be evaluated using the validated ECQ. The ECQ leads to an overall PCS and separate PCS for 10 dimensions of endometriosis care. Previously, educational level and quality of life scores were found to be associated with ECQ results. STUDY DESIGN SIZE DURATION: First, a systematic literature review was performed (PROSPERO registration number: CRD42020169872). MEDLINE, Cochrane CENTRAL and EMBASE databases were searched from inception to May 2020 for studies in any language reporting on the results of the ECQ in patients with endometriosis. Two studies were identified. From the two studies, all original data were merged. In total, data from 546 patients were available for analysis. Second, univariate and multivariate regression analyses were performed to identify determinants for patient-centeredness of endometriosis care. PARTICIPANTS/MATERIALS SETTING METHODS: The two included studies evaluated patient-centeredness in four endometriosis care centers in Belgium and the Netherlands. All participants had surgically proven endometriosis. Possible patient-specific determinants were selected from the demographic and medical questions from the first part of the ECQ. These determinants were evaluated using linear regression analysis and all possible determinants with a P > 0.2 in the univariate analysis were selected for stepwise multivariate analysis. Separate analyses were performed for overall PCS and each of the 10 dimensions. MAIN RESULTS AND THE ROLE OF CHANCE: The two included studies provided data from 546 patients. After adjustment for care center, multivariate analysis showed that a higher 'grade for endometriosis care' (B = 0.66), a 'lower educational level' (B = 0.50), 'being member of a patient organization' (B = 0.49) and 'having seen other specialists for endometriosis complaints' (B = 0.34) were independently associated with higher overall PCS (R 2 = 0.41). 'Grade for endometriosis care' was a determinant for all dimensions of endometriosis care. 'Having seen other specialists for endometriosis complaints' was positively associated with the care dimensions 'respect for patients' values, preferences and expressed needs', 'continuity and transition' and 'technical skills'. Members of a patient organization showed higher scores on the care dimensions 'emotional support and alleviation of fear and anxiety', 'continuity and transition' and 'endometriosis clinic staff'. Furthermore, we found that having a higher level of education is associated with lower scores in the care dimensions 'physical comfort', 'emotional support and alleviation of fear and anxiety' and 'involvement of significant other'. LIMITATIONS REASONS FOR CAUTION: These results delineate the patient-specific determinants of patient-centered care as measured using the Dutch ECQ. Whether results are generalizable to other countries should be investigated in an international study. This requires the ECQ to be validated in other languages first. WIDER IMPLICATIONS OF THE FINDINGS: The aforementioned determinants of patient-centered care are of value for studies benchmarking clinics for their patient-centeredness. In addition, they help clinicians to determine how to tailor their care to individual patients. At every visit, patients could be asked to grade the endometriosis care (on a scale of 0-10) to easily investigate patient-centeredness. When there is more time, women with endometriosis should be asked to complete the entire ECQ to investigate patient-centeredness in depth. STUDY FUNDING/COMPETING INTERESTS: The department of reproductive medicine (involving C.B.L. and V.M.) of the Amsterdam UMC, Vrije Universiteit Amsterdam has received several research and educational grants from Guerbet, Merck and Ferring. The authors have no conflict of interest related to this manuscript.

Towards more patient-centred endometriosis care: a cross-sectional survey using the ENDOCARE questionnaire.

STUDY QUESTION: What is the performance of the patient-centredness of endometriosis care in a secondary and a tertiary care setting and how can it be improved? SUMMARY ANSWER: Overall, patient-centredness was comparable in the two endometriosis care centres, but differed regarding 'physical comfort' and 'continuity and transition'; both centres can learn how to improve several of their targets from the other's strengths. WHAT IS KNOWN ALREADY: The ENDOCARE questionnaire (ECQ) is a validated questionnaire for assessing the important quality dimension 'patient-centredness'. Patient-centredness is associated with quality of life, although this should be explored further by larger-scale studies. STUDY DESIGN SIZE DURATION: A cross-sectional survey, relying on the ECQ, was performed (during 2015 and 2016) among 407 women with surgically diagnosed endometriosis. PARTICIPANTS/MATERIALS SETTING METHODS: This study was conducted in a secondary and a tertiary care centre in the Netherlands. A total of 209 Dutch-speaking women who had endometriosis surgery (2013-2014), completed the ECQ after a postal invitation and, if needed, postal reminders. The assessed outcomes were: overall patient-centredness, the patient-centredness for each of its 10 dimensions, and the patient-centred strengths and targets for improvement. Case-mix adjusted patient-centredness scores (PCS) were compared and strengths and targets for improvement were identified with a matrix modelling importance against experience. The need to improve the targets was quantified with quality impact indices. MAIN RESULTS AND THE ROLE OF CHANCE: No difference was demonstrated between the overall PCS of the secondary and tertiary centres (respectively: 4.8 and 4.5; P = 0.15). No difference was found in PCS per dimension between the two clinics except for the secondary care centre performing better regarding 'physical comfort' (respectively: 4.5 and 3.0; P = 0.01) and 'continuity and transition' (respectively: 6.0 and 4.2; P = 0.01). The two centres had nine targets for improvement in common. The secondary and tertiary centres, respectively, had five and seven additional centre-specific targets for improvement. Cross-centre learning is encouraged as 9 out the 12 additional centre-specific targets were strengths in the other centre. The main improvement targets were being able to contact the centre in case of emergency (both centres), the involvement of a significant other (secondary centre), diagnostic delay (secondary centre), personal follow-up (tertiary centre) and disclosing the level of competence of healthcare providers (tertiary centre). LIMITATIONS REASON FOR CAUTION: Responders did not differ from non-responders in their stage of endometriosis, educational level, rating of endometriosis care and degree to which their complaints are suppressed. Endometriosis is a chronic condition and patient-centredness might be experienced differently at other points of the endometriosis care trajectory. WIDER IMPLICATION OF THE FINDINGS: The ECQ is a useful tool to assess patient-centredness in both secondary and tertiary care centres. Further research should focus on how to improve endometriosis care. STUDY FUNDING/COMPETING INTERESTS: No external funding was used. V.M. and C.B.L. report grants from Guerbet, grants from Merck and grants from Ferring outside the submitted work. All authors declare that they have no competing interests concerning this publication.

Uterine bathing with sonography gel prior to IVF/ICSI-treatment in patients with endometriosis, a multicentre randomised controlled trial.

STUDY QUESTION: What is the effect of uterine bathing with sonography gel prior to IVF/ICSI-treatment on live birth rates after fresh embryo transfer in patients with endometriosis? SUMMARY ANSWER: After formal interim analysis and premature ending of the trial, no significant difference between uterine bathing using a pharmacologically neutral sonography gel compared to a sham procedure on live birth rate after fresh embryo transfer in endometriosis patients (26.7% vs. 15.4%, relative risk (RR) 1.73, 95% confidence interval (CI) 0.81-3.72; P-value 0.147) could be found, although the trial was underpowered to draw definite conclusions. WHAT IS KNOWN ALREADY: Impaired implantation receptivity contributes to reduced clinical pregnancy rates after IVF/ICSI-treatment in endometriosis patients. Previous studies have suggested a favourable effect of tubal flushing with Lipiodol® on natural conceptions. This benefit might also be explained by enhancing implantation through endometrial immunomodulation. Although recent studies showed no beneficial effect of endometrial scratching, the effect of mechanical stress by intrauterine infusion on the endometrium in endometriosis patients undergoing IVF/ICSI-treatment has not been investigated yet. STUDY DESIGN SIZE DURATION: We performed a multicentre, patient-blinded, randomised controlled trial in which women were randomly allocated to either a Gel Infusion Sonography (GIS, intervention group) or a sham procedure (control group) prior to IVF/ICSI-treatment. Since recruitment was slow and completion of the study was considered unfeasible, the study was halted after inclusion of 112 of the planned 184 women. PARTICIPANTS/MATERIALS SETTING METHODS: We included infertile women with surgically confirmed endometriosis ASRM stage I-IV undergoing IVF/ICSI-treatment. After informed consent, women were randomised to GIS with intrauterine instillation of ExEm-gel® or sonography with gel into the vagina (sham). This was performed in the cycle preceding the embryo transfer, on the day GnRH analogue treatment was started. The primary endpoint was live birth rate after fresh embryo transfer. Analysis was performed by both intention-to-treat and per-protocol. MAIN RESULTS AND THE ROLE OF CHANCE: Between July 2014 to September 2018, we randomly allocated 112 women to GIS (n = 60) or sham procedure (n = 52). The live birth rate after fresh embryo transfer was 16/60 (26.7%) after GIS versus 8/52 (15.4%) after the sham (RR 1.73, 95% CI 0.81-3.72; P-value 0.147). Ongoing pregnancy rate was 16/60 (26.7%) after GIS versus 9/52 (17.3%) in the controls (RR 1.54, 95% CI 0.74-3.18). Miscarriage occurred in 1/60 (1.7%) after GIS versus 5/52 (9.6%) in the controls (RR 0.17, 95% CI 0.02-1.44) women. Uterine bathing resulted in a higher pain score compared with a sham procedure (visual analogue scale score 2.7 [1.3-3.5] vs. 1.0 [0.0-2.0], P < 0.001). There were two adverse events after GIS compared with none after sham procedures. LIMITATIONS REASONS FOR CAUTION: The study was terminated prematurely due to slow recruitment and trial fatigue. Therefore, the trial is underpowered to draw definite conclusions regarding the effect of uterine bathing with sonography gel on live birth rate after fresh embryo transfer in endometriosis patients undergoing IVF/ICSI-treatment. WIDER IMPLICATIONS OF THE FINDINGS: We could not demonstrate a favourable effect of uterine bathing procedures with sonography gel prior to IVF/ICSI-treatment in patients with endometriosis. STUDY FUNDING/COMPETING INTERESTS: Investigator initiated study. IQ Medical Ventures provided the ExEm FOAM® kits free of charge, they were not involved in the study design, data management, statistical analyses and/or manuscript preparation, etc. C.B.L. reports receiving grants from Ferring, Merck and Guerbet, outside the submitted work. C.B.L. is Editor-in-Chief of Human Reproduction. V.M. reports grants and other from Guerbet, outside the submitted work. B.W.M. reports grants from NHMRC (GNT1176437), personal fees from ObsEva, Merck and Merck KGaA, Guerbet and iGenomix, outside the submitted work. N.P.J. reports research funding from Abb-Vie and Myovant Sciences and consultancy for Vifor Pharma, Guerbet, Myovant Sciences and Roche Diagnostics, outside the submitted work. K.D. reports personal fees from Guerbet, outside the submitted work. The other authors do not report any conflicts of interest. No financial support was provided. TRIAL REGISTRATION NUMBER: NL4025 (NTR4198). TRIAL REGISTRATION DATE: 7 October 2013. DATE OF FIRST PATIENT'S ENROLMENT: 22 July 2014.

SOMA-trial: surgery or medication for women with an endometrioma? Study protocol for a randomised controlled trial and cohort study.

STUDY QUESTIONS: The objective of this study is to evaluate the effectiveness and cost-effectiveness of surgical treatment of women suffering from pain due to an ovarian endometrioma when compared to treatment with medication (analgesia and/or hormones). The primary outcome is defined as successful pain reduction (-30% reduction of pain) measured by the numeric rating scale (NRS) after 6 months. Secondary outcomes include successful pain reduction after 12 and 18 months, quality of life, affective symptoms, cost-effectiveness, recurrence rate, need of adjuvant medication after surgery, ovarian reserve, adjuvant surgery and budget impact. WHAT IS KNOWN ALREADY: Evidence suggests that both medication and surgical treatment of an ovarian endometrioma are effective in reducing pain and improving quality of life. However, there are no randomised studies that compare surgery to treatment with medication. STUDY DESIGN SIZE DURATION: This study will be performed in a research network of university and teaching hospitals in the Netherlands. A multicentre randomised controlled trial and parallel prospective cohort study in patients with an ovarian endometrioma, with the exclusion of patients with deep endometriosis, will be conducted. After obtaining informed consent, eligible patients will be randomly allocated to either treatment arm (medication or surgery) by using web-based block randomisation stratified per centre. A successful pain reduction is set at a 30% decrease on the NRS at 6 months after randomisation. Based on a power of 80% and an alpha of 5% and using a continuity correction, a sample size of 69 patients in each treatment arm is needed. Accounting for a drop-out rate of 25% (i.e. loss to follow up), we need to include 92 patients in each treatment arm, i.e. 184 in total. Simultaneously, a cohort study will be performed for eligible patients who are not willing to be randomised because of a distinct preference for one of the two treatment arms. We intend to include 100 women in each treatment arm to enable standardization by inverse probability weighting, which means 200 patients in total. The expected inclusion period is 24 months with a follow-up of 18 months. PARTICIPANTS/MATERIALS SETTING METHODS: Premenopausal women (age ≥ 18 years) with pain (dysmenorrhoea, pelvic pain or dyspareunia) and an ovarian endometrioma (cyst diameter ≥ 3 cm) who visit the outpatient clinic will make up the study population. Patients with signs of deep endometriosis will be excluded. The primary outcome is successful pain reduction, which is defined as a 30% decrease of pain on the NRS at 6 months after randomisation. Secondary outcomes include successful pain reduction after 12 and 18 months, quality of life and affective symptoms, cost-effectiveness (from a healthcare and societal perspective), number of participants needing additional surgery, need of adjuvant medication after surgery, ovarian reserve and recurrence rate of endometriomas. Measurements will be performed at baseline, 6 weeks and 6, 12 and 18 months after randomisation. STUDY FUNDING/COMPETING INTERESTS: This study is funded by ZonMw, a Dutch organization for Health Research and Development, project number 80-85200-98-91041. The Department of Reproductive Medicine of the Amsterdam UMC location VUmc has received several research and educational grants from Guerbet, Merck KGaA and Ferring not related to the submitted work. B.W.J. Mol is supported by a NHMRC Practitioner Fellowship (GNT1082548) and reports consultancy for ObsEva, Merck KGaA and Guerbet. V. Mijatovic reports grants from Guerbet, grants from Merck and grants from Ferring outside the submitted work. All authors declare that they have no competing interests concerning this publication. TRIAL REGISTRATION NUMBER: Dutch Trial Register (NTR 7447, http://www.trialregister.nl). TRIAL REGISTRATION DATE: 2 January 2019. DATE OF FIRST PATIENT'S ENROLMENT: First inclusion in randomised controlled trial October 4, 2019. First inclusion in cohort May 22, 2019.

Continuous oral contraceptives versus long-term pituitary desensitization prior to IVF/ICSI in moderate to severe endometriosis: study protocol of a non-inferiority randomized controlled trial.

STUDY QUESTIONS: The primary objective is to investigate if continuous use of oral contraceptives is non-inferior compared to long-term pituitary desensitization with a GnRH agonist prior to IVF/ICSI in patients with moderate to severe endometriosis with regard to treatment efficacy. Secondary objectives concern treatment safety and cost-effectiveness. WHAT IS KNOWN ALREADY: Long-term pituitary desensitization with a GnRH agonist for 3-6 months prior to IVF/ICSI improves clinical pregnancy rates in women suffering from endometriosis. However, discussion about this treatment strategy exists because of its uncomfortable side effects. Alternatively, IVF/ICSI pre-treatment with continuously administered oral contraceptives may offer fewer side-effects and lower (in)direct costs, as well as encouraging IVF outcomes in women with endometriosis. To date, these two different IVF/ICSI pre-treatment strategies in women with endometriosis have not been directly compared. STUDY DESIGN SIZE DURATION: An open-label, parallel two-arm randomized controlled multicenter trial is planned, including patients with moderate to severe endometriosis. To demonstrate an absolute difference of 13% (delta of 10% with non-inferiority margin of 3%) with a power of 80% 137 patients per group are sufficient. Taking into account a withdrawal of patients of 10% and a cancelation rate of embryo transfer after ovarian pick up of 10% (for instance due to fertilization failure), the sample size calculation is rounded off to 165 patients per group; 330 patients in total will be included. After informed consent, eligible patients will be randomly allocated to the intervention or reference group by using web based block randomization stratified per centre. Study inclusion is expected to be complete in 3-5 years. PARTICIPANTS/MATERIALS SETTING METHODS: The research population consists of patients with moderate to severe endometriosis (ASRM III/IV) who are scheduled for their first, second or third IVF/ICSI treatment attempt. Women aged over 41 years, younger than 18 years, with a known contraindication for the use of oral contraceptives and/or GnRH agonists or with severe male factor infertility will be excluded from participation. After informed consent patients are allocated to the intervention group (one-phase oral contraceptive continuously during three subsequent months) or the reference group (three Leuprorelin 3.75 mg i.m./s.c. depot injections during three subsequent months). Tibolon 2.5 mg can be given daily as add-back therapy in the reference group. After 3 months of pre-treatment the IVF/ICSI stimulation phase will be started. The primary outcome is live birth rate after fresh embryo transfer. Secondary outcomes are cumulative live birth rate after one IVF/ICSI treatment cycle (including fresh and frozen embryo transfers up to 15 months after randomization), ongoing pregnancy rate and time to pregnancy. In addition, treatment outcome parameters, adverse events, side-effects during the first 3 months, complications, recurrence of endometriosis (complaints), quality of life, patient preferences, safety and costs effectiveness will be reported. Measurements will be performed at baseline and at 3, 6, 9, 12 and 15 months after randomization. STUDY FUNDING/COMPETING INTERESTS: All authors have no conflict of interest related to this manuscript. The department of reproductive medicine of the Amsterdam UMC location VUmc has received several research and educational grants from Guerbet, Merck and Ferring not related to the submitted work. TRIAL REGISTRATION NUMBER: The trial is registered as the COPIE trial (Continuous use of Oral contraceptives as an alternative for long-term Pituitary desensitization with a GnRH agonist prior to IVF/ICSI in Endometriosis patients) in the Dutch Trial Register (Ref. No. NTR6357, http://www.trialregister.nl). TRIAL REGISTRATION DATE: 16 March 2017. DATE OF FIRST PATIENT'S ENROLMENT: Enrollment is planned for November 2018.

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 INTERESTS: 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.