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Study Question: What is the impact of the EuroNet-PHL-C2 treatment for boys with classical Hodgkin lymphoma (cHL) on semen parameters?, Summary Answer: More than half of the patients (52%, n = 16/31) had oligozoospermia or azoospermia at 2 years from cHL diagnosis; particularly boys treated for advanced-stage cHL had low sperm counts and motility., What Is Known Already: Chemotherapy and radiotherapy to the inguinal region or testes can impair spermatogenesis and result in reduced fertility. The EuroNet-PHL-C2 trial aims to minimize radiotherapy in standard childhood cHL treatment, by intensifying chemotherapy. The present study aims to assess the (gonadotoxic) impact of this treatment protocol on semen parameters and reproductive hormones in boys aged ≤18 years., Study Design, Size, Duration: This international, prospective, multi-centre cohort study was an add-on study to the randomized phase-3 EuroNet-PHL-C2 trial, where the efficacy of standard cHL treatment with OEPA-COPDAC-28 (OEPA: vincristine, etoposide, prednisone, and doxorubicin; COPDAC-28: cyclophosphamide, vincristine, prednisone, and dacarbazine) was compared to intensified OEPA-DECOPDAC-21 chemotherapy (DECOPDAC-21: COPDAC with additional doxorubicin and etoposide and 25% more cyclophosphamide). Patients were recruited between January 2017 and September 2021., Participants/materials, Setting, Methods: Eligibility criteria included male patients, diagnosed with classical HL before or at the age of 18 years, and treated according to the EuroNet-PHL-C2 protocol in any of the 18 participating sites in the Netherlands, Germany, Belgium, Czech Republic, and Austria. Sperm parameters (sperm concentration, progressive motility, sperm volume, and calculated total motile sperm count) were assessed at diagnosis and 2 years after diagnosis in (post)pubertal boys. Laboratory measurements (serum follicle-stimulating hormone (FSH) and inhibin B) were performed in samples drawn at diagnosis, during treatment (2-3 times), and at 2 years post-diagnosis, and (age-adjusted) analyses were conducted separately for pre-pubertal and (post)pubertal boys. Outcomes were compared between the treatment levels (TL1, TL2, and TL3) and consolidation treatment schemes (COPDAC-28 and DECOPDAC-21)., Main Results and the Role of Chance: In total, 101 boys were included in the present analysis: 73 were (post)pubertal (median age 15.4 years, (IQR 14.4; 16.6), 10 TL1, 29 TL2, 34 TL3, 62% of TL2/3 patients received COPDAC-28) and 28 boys were pre-pubertal (median age 9.6 years (IQR 6.6; 11.4), 4 TL1, 7 TL2, 17 TL3, 38% of TL2/3 patients received COPDAC-28). The study included six boys who had received pelvic radiotherapy; none were irradiated in the inguinal or testicular area. At diagnosis, 48 (post)pubertal boys delivered semen for cryopreservation; 19 (40%) semen samples were oligospermic and 4 (8%) were azoospermic. Low sperm concentration (<15 mil/ml) appeared to be related to the HL disease itself, with a higher prevalence in boys who presented with B symptoms (76% vs 26%, aOR 2.3 (95% CI 1.0; 3.8), P = 0.001) compared to those without such symptoms. At 2 -years post-diagnosis, 31 boys provided semen samples for analysis, of whom 12 (39%) boys had oligozoospermia and 4 (13%) had azoospermia, while 22 boys (71%) had low total motile sperm counts (TMSC) (<20 mil). Specifically, the eight boys in the TL3 group treated with DECOPDAC-21 consolidation had low sperm counts and low progressive motility after 2 years (i.e. median sperm count 1.4 mil/ml (IQR <0.1; 5.3), n = 7 (88%), low sperm concentration, low median progressive motility 16.5% (IQR 0.0; 51.2), respectively). Age-adjusted serum FSH levels were significantly raised and inhibin B levels (and inhibin B:FSH ratios) were decreased during chemotherapy in (post)pubertal boys, with subsequent normalization in 80% (for FSH) and 60% (for inhibin B) of boys after 2 years. Only 4 out of the 14 (post)pubertal boys (29%) with low sperm concentrations after 2 years had elevated FSH (>7.6 IU/l), while 7 (50%) had low inhibin B levels (<100 ng/l). In pre-pubertal boys, reproductive hormones were low overall and remained relatively stable during chemotherapy., Limitations, Reasons for Caution: The present analyses included sperm and laboratory measurements up to 2 years post-diagnosis. Long-term reproductive outcomes and potential recovery of spermatogenesis remain unknown, while recovery was reported up to 5- or even 10-year post-chemotherapy in previous studies.Boys who were pre-pubertal at diagnosis were still too young and/or physically not able to deliver semen after 2 years and we could not assess a potential difference in gonadotoxicity according to pubertal state at the time of treatment. Overall, the statistical power of the analyses on sperm concentration and quality after 2 years was limited., Wider Implications of the Findings: Results of the semen analyses conducted among the 31 boys who had provided a semen sample at 2 years post-treatment were generally poor. However, additional long-term and adequately powered data are crucial to assess the potential recovery and clinical impact on fertility. The participating boys will be invited to deliver a semen sample after 5 years. Until these data become available, benefits of intensified chemotherapy in cHL treatment to reduce radiotherapy and lower risk for development of secondary tumours should be carefully weighed against potentially increased risk of other late effects, such as diminished fertility due to the increased chemotherapy burden. Boys with newly diagnosed cHL should be encouraged to deliver sperm for cryopreservation whenever possible. However, patients and clinicians should also realize that the overall state of disease and inflammatory milieu of cHL can negatively affect sperm quality and thereby reduce chance of successful fertility preservation. Furthermore, the measurement of FSH and inhibin B appears to be of low value in predicting low sperm quality at two years from cHL treatment., Study Funding/competing Interest(s): This study was funded by the Dutch charity foundation KiKa (project 257) that funds research on all forms of childhood cancer. C.M.-K., D.K., W.H.W., D.H., MC, A.U., and A.B. were involved in the development of the EuroNet-PHL-C2 regimen. The other authors declare no potential conflict of interest., Trial Registration Number: N/A., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Study Question: What is the impact of the EuroNet-PHL-C2 treatment protocol for children with classical Hodgkin lymphoma (cHL) on gonadal function in girls, based on assessment of serum anti-Müllerian hormone (AMH)?, Summary Answer: Serum AMH levels decreased after induction chemotherapy and increased during subsequent treatment and 2 years of follow-up, with lowest levels in patients treated for advanced stage cHL., What Is Known Already: Treatment for cHL, particularly alkylating agents and pelvic irradiation, can be gonadotoxic and result in premature reduction of primordial follicles in females. The current EuroNet-PHL-C2 trial aims to reduce the use of radiotherapy in standard childhood cHL treatment, by intensifying chemotherapy. This study aims to assess the gonadotoxic effect of the EuroNet-PHL-C2 protocol., Study Design, Size, Duration: This international, prospective, multicenter cohort study is embedded in the EuroNet-PHL-C2 trial, an European phase-3 treatment study evaluating the efficacy of standard cHL treatment with OEPA-COPDAC-28 (OEPA: vincristine, etoposide, prednisone, and doxorubicin; COPDAC-28: cyclophosphamide, vincristine, prednisone, and dacarbazine) versus intensified OEPA-DECOPDAC-21 (DECOPDAC-21: COPDAC with additional doxorubicin and etoposide and 25% more cyclophosphamide) in a randomized setting. Participants were recruited between January 2017 and September 2021., Participants/materials, Setting, Methods: Female patients aged ≤18 years, treated according to the EuroNet-PHL-C2 protocol for cHL were recruited across 18 sites in the Netherlands, Belgium, Germany, Austria, and Czech Republic. All parents and patients (aged ≥12 years old) provided written informed consent. Serum AMH levels and menstrual cycle characteristics were evaluated over time (at diagnosis, one to three times during treatment and 2 up to 5 years post-diagnosis) and compared between treatment-levels (TL1, TL2, and TL3) and treatment-arms (OEPA-COPDAC-28 and OEPA-DECOPDAC-21). Serum samples obtained from patients after receiving pelvic radiotherapy were excluded from the main analyses., Main Results and the Role of Chance: A total of 104 females, with median age at diagnosis of 15.6 years (IQR 13.7; 17.0), were included in the analysis. Ninety-nine were (post)pubertal. Eighteen girls were diagnosed with an early stage of cHL (TL1) and 86 with intermediate or advanced stage disease (50 TL2 and 36 TL3, 66% received COPDAC-28 and 34% DECOPDAC-21). Five patients received pelvic radiotherapy. Median AMH level at diagnosis was 1.7 µg/l (IQR 0.9; 2.7). After two courses of OEPA chemotherapy, AMH levels decreased substantially in all patients (98% <0.5 µg/l), followed by a significant increase during the consolidation treatment and follow-up. After 2 years, 68% of patients reached their baseline AMH value, with overall median recovery of 129% (IQR 75.0; 208.9) compared to baseline measurement. Five patients (7%) had AMH <0.5 µg/l. In patients treated for advanced stage disease, AMH levels remained significantly lower compared to early- or intermediate stage disease, with median serum AMH of 1.3 µg/l (IQR 0.8; 2.1) after 2 years. Patients who received DECOPDAC-21 consolidation had lower AMH levels during treatment than patients receiving COPDAC-28, but the difference was no longer statistically significant at 2 years post-diagnosis. Of the 35 postmenarchal girls who did not receive hormonal co-treatment, 19 (54%) experienced treatment-induced amenorrhea, two girls had persisting amenorrhea after 2 years., Limitations, Reasons for Caution: The studied population comprises young girls with diagnosis of cHL often concurring with pubertal transition, during which AMH levels naturally rise. There was no control population, while the interpretation of AMH as a biomarker during childhood is complex. The state of cHL disease may affect AMH levels at diagnosis, potentially complicating assessment of AMH recovery as a comparison with baseline AMH. The current analysis included data up to 2-5 years post-diagnosis., Wider Implications of the Findings: The current PANCARE guideline advises to use the cyclophosphamide-equivalent dose score (CED-score, as an estimation of cumulative alkylating agent exposure) with a cut-off of 6000 mg/m2 to identify females aged <25 years at high risk of infertility. All treatment-arms of the EuroNet-PHL-C2 protocol remain below this cut-off, and based on this guideline, girls treated for cHL should therefore be considered low-risk of infertility. However, although we observed an increase in AMH after chemotherapy, it should be noted that not all girls recovered to pre-treatment AMH levels, particularly those treated for advanced stages of cHL. It remains unclear how our measurements relate to age-specific expected AMH levels and patterns. Additional (long-term) data are needed to explore clinical reproductive outcomes of survivors treated according to the EuroNet-PHL-C2 protocol., Study Funding/competing Interest(s): The fertility add-on study was funded by the Dutch charity foundation KiKa (project 257) that funds research on all forms of childhood cancer. C.M-K., D.K., W.H.W., D.H., M.C., A.U., and A.B. were involved in the development of the EuroNet-PHL-C2 regimen. The other authors indicated no potential conflicts of interest., Trial Registration Number: N/A., (© The Author(s) 2024. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Study Question: Which chemotherapeutic agents and body site-specific radiation fields are dose-dependently associated with an increased risk of fertility impairment in long-term female childhood, adolescent and young adulthood (CAYA) cancer survivors?, Summary Answer: Busulfan, lower abdominal radiotherapy (RT) and total body irradiation (TBI) seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively., What Is Known Already: Several treatment-related fertility deficits, as assessed by both self-reported outcomes and hormonal markers are known to occur following treatment of CAYA cancer. However, knowledge regarding precise dose-related estimates of these treatment-related risks are scarce., Study Design, Size, Duration: The current case-control study was nested within the PanCareLIFE cohort study. In total, 1332 CAYA survivors from 8 countries, 9 institutions and 11 cohorts, participated in and contributed data to the study., Participants/materials, Setting, Methods: All participants were female 5-year CAYA cancer survivors. In total, 450 cases (fertility impaired survivors) and 882 matched controls (not fertility impaired survivors) were included. Fertility impairment was defined using both questionnaire data (primary or secondary amenorrhea; use of artificial reproductive techniques; unfulfilled wish to conceive) and hormonal data (FSH and anti-Müllerian hormone (AMH)). Multivariable logistic regression models were used to investigate the effect of (i) alkylating agent exposure, and (ii) dose categories for individual chemotherapeutic agents and for RT-exposed body sites., Main Results and the Role of Chance: A positive dose-effect relationship between cyclophosphamide equivalent dose (CED) score and fertility impairment was found, with survivors with a CED score > 7121 mg/m2 being at a significantly increased risk of fertility impairment (odds ratio (95% CI) = 2.6 (1.9-3.6) P < 0.001). Moreover, cumulative dose variables of the following treatments were significantly associated with fertility impairment: busulfan, carmustine, cyclophosphamide, melphalan, procarbazine, lower abdominal RT and TBI. Busulfan, lower abdominal RT and TBI seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively., Limitations, Reasons for Caution: Our study may have been subject to selection bias since data from about half of the original base cohorts were available for the current study. This could impact the generalizability of our study results., Wider Implications of the Findings: We identified survivors at high risk for fertility impairment and, consequently, for a reduced or even absent reproductive life span. Both girls and young women who are about to start anti-cancer treatment, as well as adult female survivors, should be counselled about future parenthood and referred to a reproductive specialist for fertility preservation, if desired., Study Funding/competing Interest(s): This study has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 602030. There are no competing interests., Trial Registration Number: n/a., (© The Author(s) 2021. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Study Question: Are the long-term reproductive outcomes following recurrent dilatation and curettage (D&C) for miscarriage in women with identified and treated intrauterine adhesions (IUAs) comparable to women without IUAs., Summary Answer: Reproductive outcomes in women with identified and treated IUAs following recurrent D&C for miscarriage are impaired compared to women without IUAs; fewer ongoing pregnancies and live births are achieved with a prolonged time to a live birth., What Is Known Already: The Prevention of Adhesions Post Abortion (PAPA) study showed that application of auto-crosslinked hyaluronic acid (ACP) gel, an absorbable barrier in women undergoing recurrent D&C for miscarriage resulted in a lower rate of IUAs, 13% versus 31% (relative risk 0.43, 95% CI 0.22 to 0.83), lower mean adhesion score and significant less moderate to severe IUAs. It is unclear what the impact is of IUAs on long-term reproductive performance., Study Design, Size, Duration: This was a follow-up of the PAPA study, a multicenter randomized controlled trial evaluating the application of ACP gel in women undergoing recurrent D&C for miscarriage. All included women received a diagnostic hysteroscopy 8-12 weeks after randomization to evaluate the uterine cavity and for adhesiolysis if IUAs were present. Here, we present the reproductive outcomes in women with identified and treated IUAs versus women without IUAs, 46 months after randomization., Participants/materials, Setting, Methods: Between December 2011 and July 2015, 152 women with a first-trimester miscarriage with at least one previous D&C, were randomized for D&C alone or D&C with immediate intrauterine application of ACP gel. Participants were approached at least 30 months after randomization to evaluate reproductive performance, obstetric and neonatal outcomes and cycle characteristics. Additionally, the medical files of all participants were reviewed. Main outcome was ongoing pregnancy. Outcomes of subsequent pregnancies, time to conception and time to live birth were also recorded., Main Results and the Role of Chance: In women pursuing a pregnancy, 14/24 (58%) ongoing pregnancies were recorded in women with identified and treated IUAs versus 80/89 (90%) ongoing pregnancies in women without IUAs odds ratio (OR) 0.18 (95% CI 0.06 to 0.50, P-value <0.001). Documented live birth was also lower in women with IUAs; 13/24 (54%) with versus 75/89 (84%) without IUAs, OR 0.22 (95% CI: 0.08 to-0.59, P-value 0.004). The median time to conception was 7 months in women with identified and treated IUAs versus 5 months in women without IUAs (hazard ratio (HR) 0.84 (95% CI 0.54 to 1.33)) and time to conception leading to a live birth 15 months versus 5.0 months (HR 0.54 (95% CI: 0.30 to 0.97)). In women with identified and treated IUAs, premature deliveries were recorded in 3/16 (19%) versus 4/88 (5%) in women without IUAs, P-value 0.01. Complications were recorded in respectively 12/16 (75%) versus 26/88 (30%), P-value 0.001. No differences were recorded in mean birth weight between the groups., Limitations, Reasons for Caution: In the original PAPA study, randomization was applied for ACP gel application. Comparing women with and without IUAs is not in line with the randomization and therefore confounding of the results cannot be excluded. IUAs, if visible during routine hysteroscopy after randomization were removed as part of the study protocol; the influence of IUAs on reproductive outcome may therefore be underestimated. Women undergoing a recurrent D&C for miscarriage were included, a specific group likely to generate clinically significant adhesions. The findings should therefore not be generalized to all women undergoing D&C for miscarriage., Wider Implications of the Findings: As IUAs have an impact on reproductive performance, even after hysteroscopic adhesiolysis, primary prevention is essential. Expectative and medical management should therefore be considered as serious alternatives for D&C in women with a miscarriage. In case D&C is necessary, application of ACP gel should be considered., Study Funding/competing Interest(s): The original PAPA study (NTR 3120) was an investigator initiated study that was funded by the Foundation for scientific investigation in Obstetrics and Gynaecology of the Saint Lucas Andreas Hospital (currently renamed OLVG Oost), SWOGA. The syringes containing ACP gel were received from Anika Therapeutics, the manufacturer of Hyalobarrier® Gel Endo. The current follow-up study was also an investigator-initiated study without funding. The funder and sponsor had no role in the design of this follow-up study, data collection, data analysis, data interpretation, trial design, patient recruitment, writing of the report or any aspect pertinent to the study. ABH, RAL, JAFH and JWRT have no conflict to declare. HAMB reports being a member of safety board research Womed., Trial Registration Number: Netherlands Trial Register NTR 3120., (© The Author(s) 2020. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology.)

Study Question: Does a previous Caesarean section affect reproductive outcomes, including live birth, in women after IVF or ICSI?, Summary Answer: A previous Caesarean section impairs live birth rates after IVF or ICSI compared to a previous vaginal delivery., What Is Known Already: Rates of Caesarean sections are rising worldwide. Late sequelae of a Caesarean section related to a niche (Caesarean scar defect) include gynaecological symptoms and obstetric complications. A systematic review reported a lower pregnancy rate after a previous Caesarean section (RR 0.91 CI 0.87-0.95) compared to a previous vaginal delivery. So far, studies have been unable to causally differentiate between problems with fertilisation, and the transportation or implantation of an embryo. Studying an IVF population allows us to identify the effect of a previous Caesarean section on the implantation of embryos in relation to a previous vaginal delivery., Study Design, Size, Duration: We retrospectively studied the live birth rate in women who had an IVF or ICSI treatment at the IVF Centre, Amsterdam UMC, location VUmc, Amsterdam, the Netherlands, between 2006 and 2016 with one previous delivery. In total, 1317 women were included, of whom 334 had a previous caesarean section and 983 had previously delivered vaginally., Participants/materials, Setting, Methods: All secondary infertile women, with only one previous delivery either by caesarean section or vaginal delivery, were included. If applicable, only the first fresh embryo transfer was included in the analyses. Patients who did not intend to undergo embryo transfer were excluded. The primary outcome was live birth. Multivariate logistic regression analyses were used with adjustment for possible confounders ((i) age; (ii) pre-pregnancy BMI; (iii) pre-pregnancy smoking; (iv) previous fertility treatment; (v) indication for current fertility treatment: (a) tubal, (b) male factor and (c) endometriosis; (vi) embryo quality; and (vii) endometrial thickness), if applicable. Analysis was by intention to treat (ITT)., Main Results and the Role of Chance: Baseline characteristics of both groups were comparable. Live birth rates were significantly lower in women with a previous caesarean section than in women with a previous vaginal delivery, 15.9% (51/320) versus 23.3% (219/941) (OR 0.63 95% CI 0.45-0.87) in the ITT analyses. The rates were also lower for ongoing pregnancy (20.1 versus 28.1% (OR 0.64 95% CI 0.48-0.87)), clinical pregnancy (25.7 versus 33.8% (OR 0.68 95% CI 0.52-0.90)) and biochemical test (36.2 versus 45.5% (OR 0.68 95% CI 0.53-0.88)). The per protocol analyses showed the same differences (live birth rate OR 0.66 95% CI 0.47-0.93 and clinical pregnancy rate OR 0.72 95% CI 0.54-0.96)., Limitations, Reasons for Caution: This study is limited by its retrospective design. Furthermore, 56 (16.3%) cases lacked data regarding delivery outcomes, but these were equally distributed between the two groups., Wider Implications of the Findings: The lower clinical pregnancy rates per embryo transfer indicate that implantation is hampered after a caesarean section. Its relation with a possible niche (caesarean scar defect) in the uterine caesarean scar needs further study. Our results should be discussed with clinicians and patients who consider an elective caesarean section., Study Funding/competing Interest(s): Not applicable., Trial Registration Number: This study has been registered in the Dutch Trial Register (Ref. No. NL7631 http://www.trialregister.nl)., (© The Author(s) 2019. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology.)

Study Question: Which treatment-related factors are (dose-dependently) associated with abnormal hormonal and ultrasound markers of ovarian reserve in female childhood cancer survivors (CCSs)?, Summary Answer: Cyclophosphamide, procarbazine, a composite group of 'other alkylating agents', dactinomycin, doxorubicin, mitoxantrone, spinal radiotherapy (RT), abdominal/pelvic RT and total body irradiation were multivariably associated with abnormal ovarian reserve markers, with dose-effect relationships being established for procarbazine and abdominal/pelvic RT., What Is Known Already: Female childhood cancer survivors are at an increased risk of reduced ovarian function and reserve, but knowledge regarding the long-term effects of individual chemotherapeutic (CT) agents and radiotherapy fields and their respective doses is limited., Study Design, Size, Duration: The DCOG LATER-VEVO is a nationwide retrospective cohort study in which measurements were performed between 2008 and 2014. In total, 1749 female 5-year CCSs, diagnosed before age 18 years between 1963 and 2002 and 1201 controls were invited for the study., Participants/materials, Setting, Methods: Ovarian reserve was assessed by anti-Müllerian hormone (AMH), follicle stimulating hormone (FSH), inhibin B levels, and antral follicle counts (AFC). The study was a multicentre study including all seven Dutch Centers for Paediatric Oncology/Haematology., Main Results and the Role of Chance: In total, 564 CCs and 390 controls participated in the clinical part of the study. Overall, 7.0-17.7% of CCSs and 2.4-13.6% of controls had abnormal ovarian reserve markers. Above age 35, significantly more CCSs than controls had abnormal ovarian reserve markers (AMH: 26% vs. 4%; AFC: 20% vs. 3%; inhibin B: 42% vs. 16%). For AMH and FSH, significant differences were also found below age 35. Cyclophosphamide, procarbazine, a group of 'other alkylating agents', dactinomycin, doxorubicin, mitoxantrone, spinal RT, abdominal/pelvic RT and total body irradiation were multivariably associated with at least one abnormal ovarian reserve marker. Dose-effect relationships were established for procarbazine and abdominal/pelvic RT., Limitations, Reasons for Caution: Despite the large scale of the study, dose-effect relationships could not be investigated for all types of treatment due to a limited numbers of participants for specific analyses., Wider Implications of the Findings: This study demonstrated that the majority of CCSs do not show signs of a reduced ovarian reserve. However, specific subgroups of CCSs appear to be associated with a high risk. Our results are important for counselling CCSs and future patients regarding parenthood and fertility preservation., Study Funding/competing Interests: This study was funded by the Dutch Cancer Society (Grant no. VU 2006-3622) and by the Children Cancer Free Foundation (Project no. 20). Philips Health Systems Benelux supported this study by providing three ultrasound systems and concomitant analytic software. There are no competing interests., Trial Registration Number: NTR2922 http://www.trialregister.nl/trialreg/admin/rctview.asp?TC = 2922., (© The Author(s) 2018. Published by Oxford University Press on behalf of the European Society of Human Reproduction and Embryology. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.)