Abstract: Does assisted reproduction, such as ovarian stimulation and/or laboratory procedures, have impact on perinatal outcomes of singleton live births compared to natural conception in couples with unexplained subfertility? SUMMARY ANSWER Compared to natural conception, singletons born after intrauterine insemination with ovarian stimulation (IUI-OS) had a lower birthweight, while singletons born after IVF had comparable birthweights, in couples with unexplained subfertility. WHAT IS KNOWN ALREADY Singletons conceived by assisted reproduction have different perinatal outcomes such as low birthweight and a higher risk of premature birth than naturally conceived singletons. This might be due to the assisted reproduction, such as laboratory procedures or the ovarian stimulation, or to an intrinsic factor in couples with subfertility. STUDY DESIGN, SIZE, DURATION We performed a prospective cohort study using the follow-up data of two randomized clinical trials performed in couples with unexplained subfertility. We evaluated perinatal outcomes of 472 live birth singletons conceived after assisted reproduction or after natural conception within the time horizon of the studies. PARTICIPANTS/MATERIALS, SETTING, METHODS To assess the possible impact of ovarian stimulation we compared the singletons conceived after IUI with FSH or clomiphene citrate (CC) and IVF in a modified natural cycle (IVF-MNC) or standard IVF with single embryo transfer (IVF-SET) to naturally conceived singletons in the same cohorts. To further look into the possible effect of the laboratory procedures, we put both IUI and IVF groups together into IUI-OS and IVF and compared both to singletons born after natural conception. We only included singletons conceived after fresh embryo transfers. The main outcome was birthweight presented as absolute weight in grams and gestational age- and gender-adjusted percentiles. We calculated differences in birthweight using regression analyses adjusted for maternal age, BMI, smoking, parity, duration of subfertility and child gender. MAIN RESULTS AND THE ROLE OF CHANCE In total, there were 472 live birth singletons. Of the 472 singleton pregnancies, 209 were conceived after IUI-OS (136 with FSH and 73 with CC as ovarian stimulation), 138 after IVF (50 after IVF-MNC and 88 after IVF-SET) and 125 were conceived naturally. Singletons conceived following IUI-FSH and IUI-CC both had lower birthweights compared to naturally conceived singletons (adjusted difference IUI-FSH −156.3 g, 95% CI −287.9 to −24.7; IUI-CC −160.3 g, 95% CI −316.7 to −3.8). When we compared IVF-MNC and IVF-SET to naturally conceived singletons, no significant difference was found (adjusted difference IVF-MNC 75.8 g, 95% CI −102.0 to 253.7; IVF-SET −10.6 g, 95% CI −159.2 to 138.1). The mean birthweight percentile was only significantly lower in the IUI-FSH group (−7.0 percentile, 95% CI −13.9 to −0.2). The IUI-CC and IVF-SET group had a lower mean percentile and the IVF-MNC group a higher mean percentile, but these groups were not significant different compared to the naturally conceived group (IUI-CC −5.1 percentile, 95% CI −13.3 to 3.0; IVF-MNC 4.4 percentile, 95% CI −4.9 to 13.6; IVF-SET −1.3 percentile, 95% CI −9.1 to 6.4). Looking at the laboratory process that took place, singletons conceived following IUI-OS had lower birthweights than naturally conceived singletons (adjusted difference −157.7 g, 95% CI −277.4 to −38.0). The IVF group had comparable birthweights with the naturally conceived group (adjusted difference 20.9 g, 95% CI −110.8 to 152.6). The mean birthweight percentile was significantly lower in the IUI-OS group compared to the natural group (−6.4 percentile, 95% CI −12.6 to −0.1). The IVF group was comparable (0.7 percentile, 95% CI −6.1 to 7.6). LIMITATIONS, REASONS FOR CAUTION The results are limited by the number of cases. The data were collected prospectively alongside the randomized controlled trials, but analyzed as treated. WIDER IMPLICATIONS OF THE FINDINGS Our data suggest IUI in a stimulated cycle may have a negative impact on the birthweight of the child and possibly on pre-eclampsia. Further research should look into the effect of different methods of ovarian stimulation on placenta pathology and pre-eclampsia in couples with unexplained subfertility using naturally conceived singletons in the unexplained population as a reference. STUDY FUNDING/COMPETING INTEREST(S) Both initial trials were supported by a grant from ZonMW, the Dutch Organization for Health Research and Development (INeS 120620027, SUPER 80-83600-98-10192). The INeS study also had a grant from Zorgverzekeraars Nederland, the Dutch association of healthcare insurers (09-003). B.W.J.M. is supported by an NHMRC investigator Grant (GNT1176437) and reports consultancy for ObsEva, Merck Merck KGaA, Guerbet and iGenomix, outside the submitted work. A.H. reports grants from Ferring Pharmaceutical company (the Netherlands), outside the submitted work. F.J.M.B. receives monetary compensation as a member of the external advisory board for Merck Serono (the Netherlands), Ferring Pharmaceutics BV (the Netherlands) and Gedeon Richter (Belgium), he receives personal fees from educational activities for Ferring BV (the Netherlands) and for advisory and consultancy work for Roche and he receives research support grants from Merck Serono and Ferring Pharmaceutics BV, outside the submitted work. The remaining authors have nothing to disclose. TRIAL REGISTRATION NUMBER INeS study Trial NL915 (NTR939); SUPER Trial NL3895 (NTR4057)

Abstract: Are patients’ characteristics, such as anti-Müllerian hormone (AMH) and BMI, reliable factors to predict ovarian response in couples with unexplained subfertility undergoing IUI with ovarian hyperstimulation (IUI-OH)? SUMMARY ANSWER We observed no solid relationship between serum AMH and ovarian response. WHAT IS KNOWN ALREADY Ovarian stimulation during IUI treatment could lead to a higher chance of pregnancy, but also a higher incidence of multiple pregnancies, unless strict cancellation criteria are being used. Several factors could influence the result of the stimulation, such as age, BMI and hormonal status of the female. In IVF treatment, AMH has shown to be a useful predictor of ovarian stimulation to optimize the outcome; however, in a milder stimulation protocol, such as IUI, this has not been investigated. STUDY DESIGN, SIZE, DURATION We performed a prospective cohort study and evaluated the first IUI stimulation cycle of 492 patients. The study was conducted between 2012 and 2017. Follow-up ended if patients were not pregnant after the first cycle. If pregnancy did occur, follow-up lasted until delivery. PARTICIPANTS/MATERIALS, SETTING, METHODS PRORAILS is a large multicentre nationwide cohort study executed in the Netherlands. Eligible women aged 18–43 years who were diagnosed with unexplained subfertility or mild male subfertility according to the Dutch guideline, with a regular indication for IUI-OH, were asked to participate. Ovarian response was assessed using a transvaginal ultrasound 5–7 days after initiation of the stimulation and was repeated according to the size of the leading follicles. Ovarian response was defined as optimal or suboptimal based on the total number of dominant follicles & gt;15 mm. A successful stimulation was defined as the presence of two to three follicles & gt;15 mm on the day of hCG administration. Serum AMH (µg/l) was measured by ELISA, and samples were taken on day 2, 3 or 4 of the menstrual cycle. Poisson regression was used to estimate the risk of a suboptimal ovarian response. MAIN RESULTS AND THE ROLE OF CHANCE Of the 492 participants, the mean age was 33 years and the mean subfertility duration was 2.5 years. The median serum AMH was 2.1 (µg/l). The majority of patients had a suboptimal response: 326 women (66%), of whom 224 (45%) had a hypo response (defined as & lt;two follicles sized & gt; 15 mm) and 102 (21%) had a hyper response (defined as more than three follicles sized & gt;15 mm). The lowest AMH category showed a trend towards a smaller risk of a suboptimal response (relative risk ratio 0.76 (95% CI 0.54, 1.06)), but this effect did not reach statistical significance. In the prediction models, BMI and serum basal FSH were significant predictors of a hypo response, while for hyper response the factors age, BMI and serum FSH were significant. A higher BMI showed a higher risk for hypo response, as did a higher FSH whereas a lower BMI and lower FSH showed a higher risk for hyper response. The addition of AMH to the models did not improve the predictive abilities. LIMITATIONS, REASONS FOR CAUTION Although the study was prospective, the main analyses were cross-sectional with characteristics measured at one time-point. The study was not powered to provide insight into predictors of pregnancy and live births and, therefore, the result for pregnancy should be interpreted with caution. WIDER IMPLICATIONS OF THE FINDINGS This was the first large multicentre study that investigated the characteristics of ovarian response categories using standardized methods and centrally analysed laboratory measures. PRORAILS is a nationwide study with 15 hospitals and, therefore, these results are generalizable to other hospitals in the Netherlands. This study provides high-quality outcomes advancing the subfertility research field. Future studies would benefit from a randomized design investigating the effectiveness of an individualized approach versus a fixed dose. Also, the relation between a good ovarian stimulation and pregnancy rate could be further investigated. STUDY FUNDING/COMPETING INTEREST(S) The PRORAILS study is sponsored by Merck B.V., Schiphol-Rijk, the Netherlands, an affiliation of Merck KGaA, Darmstadt, Germany (EMR700623_612). Merck KGaA, Darmstadt, Germany, reviewed the manuscript prior to submission. The opinions remain those of the authors. Merck KGaA, Darmstadt, Germany, had no influence on the use of medication in this study. The recombinant FSH was mostly provided by Merck B.V. or MSD. F.B. is a member of the external advisory board for Merck B.V., Schiphol-Rijk, the Netherlands, and has received a research grant from Merck B.V., Schiphol-Rijk. H.v.B. is an employee from IQVIA, which is a commercial data-analysing company, and received payment for her part in the article. TRIAL REGISTRATION NUMBER NCT01662180.

Abstract: Does endometrial scratching in women with one failed IVF/ICSI treatment affect the chance of a live birth of the subsequent fresh IVF/ICSI cycle? SUMMARY ANSWER In this study, 4.6% more live births were observed in the scratch group, with a likely certainty range between −0.7% and +9.9%. WHAT IS KNOWN ALREADY Since the first suggestion that endometrial scratching might improve embryo implantation during IVF/ICSI, many clinical trials have been conducted. However, due to limitations in sample size and study quality, it remains unclear whether endometrial scratching improves IVF/ICSI outcomes. STUDY DESIGN, SIZE, DURATION The SCRaTCH trial was a non-blinded randomised controlled trial in women with one unsuccessful IVF/ICSI cycle and assessed whether a single endometrial scratch using an endometrial biopsy catheter would lead to a higher live birth rate after the subsequent IVF/ICSI treatment compared to no scratch. The study took place in 8 academic and 24 general hospitals. Participants were randomised between January 2016 and July 2018 by a web-based randomisation programme. Secondary outcomes included cumulative 12-month ongoing pregnancy leading to live birth rate. PARTICIPANTS/MATERIALS, SETTING, METHODS Women with one previous failed IVF/ICSI treatment and planning a second fresh IVF/ICSI treatment were eligible. In total, 933 participants out of 1065 eligibles were included (participation rate 88%). MAIN RESULTS AND THE ROLE OF CHANCE After the fresh transfer, 4.6% more live births were observed in the scratch compared to control group (110/465 versus 88/461, respectively, risk ratio (RR) 1.24 [95% CI 0.96–1.59]). These data are consistent with a true difference of between −0.7% and +9.9% (95% CI), indicating that while the largest proportion of the 95% CI is positive, scratching could have no or even a small negative effect. Biochemical pregnancy loss and miscarriage rate did not differ between the two groups: in the scratch group 27/153 biochemical pregnancy losses and 14/126 miscarriages occurred, while this was 19/130 and 17/111 for the control group (RR 1.21 (95% CI 0.71–2.07) and RR 0.73 (95% CI 0.38–1.40), respectively). After 12 months of follow-up, 5.1% more live births were observed in the scratch group (202/467 versus 178/466), of which the true difference most likely lies between −1.2% and +11.4% (95% CI). LIMITATIONS, REASONS FOR CAUTION This study was not blinded. Knowledge of allocation may have been an incentive for participants allocated to the scratch group to continue treatment in situations where they may otherwise have cancelled or stopped. In addition, this study was powered to detect a difference in live birth rate of 9%. WIDER IMPLICATIONS OF THE FINDINGS The results of this study are an incentive for further assessment of the efficacy and clinical implications of endometrial scratching. If a true effect exists, it may be smaller than previously anticipated or may be limited to specific groups of women undergoing IVF/ICSI. Studying this will require larger sample sizes, which will be provided by the ongoing international individual participant data-analysis (PROSPERO CRD42017079120). At present, endometrial scratching should not be performed outside of clinical trials. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by ZonMW, the Dutch organisation for funding healthcare research. J.S.E. Laven reports grants and personal fees from AnshLabs (Webster, Tx, USA), Ferring (Hoofddorp, The Netherlands) and Ministry of Health (CIBG, The Hague, The Netherlands) outside the submitted work. A.E.P. Cantineau reports ‘other’ from Ferring BV, personal fees from Up to date Hyperthecosis, ‘other’ from Theramex BV, outside the submitted work. E.R. Groenewoud reports grants from Titus Health Care during the conduct of the study. A.M. van Heusden reports personal fees from Merck Serono, personal fees from Ferring, personal fees from Goodlife, outside the submitted work. F.J.M. Broekmans reports personal fees as Member of the external advisory board for Ferring BV, The Netherlands, personal fees as Member of the external advisory board for Merck Serono, The Netherlands, personal fees as Member of the external advisory for Gedeon Richter, Belgium, personal fees from Educational activities for Ferring BV, The Netherlands, grants from Research support grant Merck Serono, grants from Research support grant Ferring, personal fees from Advisory and consultancy work Roche, outside the submitted work. C.B. Lambalk reports grants from Ferring, grants from Merck, grants from Guerbet, outside the submitted work. TRIAL REGISTRATION NUMBER Registered in the Netherlands Trial Register (NL5193/NTR 5342). TRIAL REGISTRATION DATE 31 July 2015. DATE OF FIRST PATIENT’S ENROLMENT 26 January 2016.

Abstract: Is a single endometrial scratch prior to the second fresh IVF/ICSI treatment cost-effective compared to no scratch, when evaluated over a 12-month follow-up period? SUMMARY ANSWER The incremental cost-effectiveness ratio (ICER) for an endometrial scratch was €6524 per additional live birth, but due to uncertainty regarding the increase in live birth rate this has to be interpreted with caution. WHAT IS KNOWN ALREADY Endometrial scratching is thought to improve the chances of success in couples with previously failed embryo implantation in IVF/ICSI treatment. It has been widely implemented in daily practice, despite the lack of conclusive evidence of its effectiveness and without investigating whether scratching allows for a cost-effective method to reduce the number of IVF/ICSI cycles needed to achieve a live birth. STUDY DESIGN, SIZE, DURATION This economic evaluation is based on a multicentre randomized controlled trial carried out in the Netherlands (SCRaTCH trial) that compared a single scratch prior to the second IVF/ICSI treatment with no scratch in couples with a failed full first IVF/ICSI cycle. Follow-up was 12 months after randomization. Economic evaluation was performed from a healthcare and societal perspective by taking both direct medical costs and lost productivity costs into account. It was performed for the primary outcome of biochemical pregnancy leading to live birth after 12 months of follow-up as well as the secondary outcome of live birth after the second fresh IVF/ICSI treatment (i.e. the first after randomization). To allow for worldwide interpretation of the data, cost level scenario analysis and sensitivity analysis was performed. PARTICIPANTS/MATERIALS, SETTING, METHODS From January 2016 until July 2018, 933 women with a failed first IVF/ICSI cycle were included in the trial. Data on treatment and pregnancy were recorded up until 12 months after randomization, and the resulting live birth outcomes (even if after 12 months) were also recorded. Total costs were calculated for the second fresh IVF/ICSI treatment and for the full 12 month period for each participant. We included costs of all treatments, medication, complications and lost productivity costs. Cost-effectiveness analysis was carried out by calculating ICERs for scratch compared to control. Bootstrap resampling was used to estimate the uncertainty around cost and effect differences and ICERs. In the sensitivity and scenario analyses, various unit costs for a single scratch were introduced, amongst them, unit costs as they apply for the United Kingdom (UK). MAIN RESULTS AND THE ROLE OF CHANCE More live births occurred in the scratch group, but this also came with increased costs over a 12-month period. The estimated chance of a live birth after 12 months of follow-up was 44.1% in the scratch group compared to 39.3% in the control group (risk difference 4.8%, 95% CI −1.6% to +11.2%). The mean costs were on average €283 (95% CI: −€299 to €810) higher in the scratch group so that the point average ICER was €5846 per additional live birth. The ICER estimate was surrounded with a high level of uncertainty, as indicated by the fact that the cost-effectiveness acceptability curve (CEAC) showed that there is an 80% chance that endometrial scratching is cost-effective if society is willing to pay ∼€17 500 for each additional live birth. LIMITATIONS, REASONS FOR CAUTION There was a high uncertainty surrounding the effects, mainly in the clinical effect, i.e. the difference in the chance of live birth, which meant that a single straightforward conclusion could not be ascertained as for now. WIDER IMPLICATIONS OF THE FINDINGS This is the first formal cost-effectiveness analysis of endometrial scratching in women undergoing IVF/ICSI treatment. The results presented in this manuscript cannot provide a clear-cut expenditure for one additional birth, but they do allow for estimating costs per additional live birth in different scenarios once the clinical effectiveness of scratching is known. As the SCRaTCH trial was the only trial with a follow-up of 12 months, it allows for the most complete estimation of costs to date. STUDY FUNDING/COMPETING INTEREST(S) This study was funded by ZonMW, the Dutch organization for funding healthcare research. A.E.P.C., F.J.M.B., E.R.G. and C.B. L. reported having received fees or grants during, but outside of, this trial. TRIAL REGISTRATION NUMBER Netherlands Trial Register (NL5193/NTR 5342).