Clinical outcome of non hcg-primed oocyte in vitro maturation treatment in patients with polycystic ovaries and polycystic ovary syndrome

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1 Clinical outcome of non hcg-primed oocyte in vitro maturation treatment in patients with polycystic ovaries and polycystic ovary syndrome Michel De Vos, M.D., Ph.D., a Carolina Ortega-Hrepich, M.D., a Firas K. Albuz, Ph.D., b Luis Guzman, M.Sc., b Nikolaos P. Polyzos, M.D., Ph.D., a Johan Smitz, M.D., Ph.D., b and Paul Devroey, M.D., Ph.D. a a Center for Reproductive Medicine, and b Follicle Biology Laboratory, Universitair Ziekenhuis Brussel, Brussels, Belgium Objective: To compare clinical outcomes of fresh embryo transfer (ET) and vitrified-warmed ET in an artificial endometrial priming cycle in patients with polycystic ovaries (PCO) or polycystic ovary syndrome (PCOS) who underwent oocyte in vitro maturation (IVM) in non hcg-primed cycles. Design: Prospective cohort study. Setting: University-based tertiary referral center. Patient(s): Thirty-nine consecutive patients <37 years old with PCO or PCOS, who underwent 73 cycles of immature oocyte retrieval. Intervention(s): Immature oocyte collection after ovarian stimulation with a cumulative dose of 450 IU ufsh or highly purified hmg, but without hcg priming. IVM of oocytes followed by ET if endometrium thickness R6 mm. Embryo vitrification at the cleavage stage. ET in an artificial cycle. Main Outcome Measure(s): Implantation rate (IR) and clinical pregnancy rate (CPR). Result(s): Fresh ET after IVM resulted in an IR of 6.9% (5/72) per ET and a CPR of 9.4% (5/53). ET of vitrifiedwarmed IVM embryos in an artificial cycle resulted in significantly better outcomes (IR 21.9% [7/32] and CPR 31.8% [7/22] per ET). Conclusion(s): A non hcg-primed IVM system in PCO or PCOS performs poorly when embryos are transfered in a fresh cycle. Transfer of vitrified-warmed IVM embryos in an artificial cycle leads to significantly improved clinical outcomes. These data illustrate that IVM embryos in PCO or PCOS have good survival rates and suggest that hcg may be needed to support endometrial receptivity in the fresh IVM cycle. (Fertil Steril Ò 2011;96: Ó2011 by American Society for Reproductive Medicine.) Key Words: IVM, non hcg-primed, embryo vitrification, artificial endometrial priming cycle Received April 15, 2011; revised July 8, 2011; accepted July 19, 2011; published online August 24, M.D.V. has nothing to disclose. C.O.-H. has nothing to disclose. F.K.A. has nothing to disclose. L.G. has nothing to disclose. N.P.P. has nothing to disclose. J.S. has nothing to disclose. P.D. has nothing to disclose. Supported by a grant from the Institute for the Promotion of Innovation by Science and Technology in Flanders, project no. IWT Reprint requests: Michel De Vos, M.D., Ph.D., UZ Brussel, Laarbeeklaan 101, 1090 Brussels, Belgium ( mdv@uzbrussel.be). Oocyte in vitro maturation (IVM) is an artificial reproductive technology (ART) where oocytes are collected from antral follicles, typically from unstimulated or minimally stimulated ovaries, and cultured, matured, and fertilized in vitro (1). Because of the simplicity of the clinical approach and the absence of any risk of ovarian hyperstimulation syndrome (OHSS), the major asset of IVM is its patient-friendliness. Women with a high antral follicle count can yield a high number of immature oocytes. Patients with polycystic ovary syndrome (PCOS) or ultrasound-only polycystic ovaries (PCO) represent, therefore, a major target population for IVM treatment. Marked improvements of the clinical and laboratory aspects of IVM treatment have led to better clinical outcomes, although the implantation potential of IVM-derived embryos is still suboptimal. Outcomes vary importantly between different centers, which is, at least partly, owing to differences in IVM cycle treatment (stimulation with gonadotropins or not, hcg triggering or not) (2). Human chorionic gonadotropin (hcg) priming before immature oocyte retrieval in patients with PCOS leads to an increased maturation rate of the collected oocytes (3); nonetheless, robust evidence regarding the effect of hcg priming on pregnancy rates in IVMtreated women with PCOS is currently not available. The practice of hcg priming yields an important population of in vivo matured oocytes, also from follicles <12 mm, because LH receptors can be present in granulosa cells from small follicles (4, 5). The action of hcg is enhanced by FSH priming, at least in women with normal ovaries and regular cycles (6). However, hcg triggers spontaneous meiotic resumption and leads to the interruption of communication within the oocyte-cumulus complex (OCC) and might therefore compromise subsequent oocyte and embryonic developmental potential (7). Furthermore, hcg priming results in the retrieval of a mixture of in-vivo matured oocytes and geminal vesicle stage (GV) oocytes. This heterogeneity of oocyte maturation stages at oocyte retrieval may result in differential fertilization schedules, thereby increasing work load for the laboratory staff. Finally, dealing with embryos of dyssynchronous developmental stages may complicate the embryo transfer and cryopreservation policies. Some authors have proposed that dyssynchrony of the window of implantation of the endometrium and the developing embryo is an important impediment to implantation in IVM cycles (8). The available time for the obligatory transformation from an early proliferative to a secretory endometrium is limited in IVM; even when current endometrial priming protocols may be beneficial for endometrial thickness, endometrial receptivity may still be compromised in many IVM cycles. Nevertheless, the status of endometrial development under different priming conditions remains underinvestigated. 860 Fertility and Sterility â Vol. 96, No. 4, October /$36.00 Copyright ª2011 American Society for Reproductive Medicine, Published by Elsevier Inc. doi: /j.fertnstert

2 The first reported IVM pregnancy (9) occurred in an IVM-derived oocyte recipient. On a similar note, good pregnancy rates were obtained in recipients of IVM-derived embryos in an oocyte donation program, comparable to those of stimulated oocyte-donor cycles (10). Embryo transfer in an artificial endometrial priming cycle obviates the concern of potential dyssynchrony of the endometrium and the embryo; because excellent survival rates of vitrified IVMderived embryos have been reported (11, 12), this may be an effective strategy to enhance outcomes after IVM treatment. We report here the clinical outcomes, in patients with PCO or PCOS, of transfer of embryos derived exclusively from GV oocytes that had been retrieved from small antral follicles without hcg trigger and matured in vitro. MATERIALS AND METHODS Patient Population The Center for Reproductive Medicine at Universitair Ziekenhuis Brussel introduced IVM as a routine treatment in January Institutional Review Board approval was obtained. Between January 2010 and October 2010, 39 consecutive patients with PCO or PCOS (according to the Rotterdam criteria, 2003 [13, 14]) were offered IVM treatment after undergoing an initial evaluation, including medical and gynecologic history taking, a baseline pelvic ultrasound scan, and blood tests for human immunodeficiency virus types I and II, hepatitis B surface antigen, and hepatitis C antibody (Supplemental Fig. 1, available online at Informed consent was obtained from all patients. IVM Cycle Characteristics Spontaneously menstruating patients underwent a baseline ultrasound scan of the ovaries on day 2 of the menstrual cycle to measure the number and sizes of antral follicles and the endometrial thickness as well as to exclude the presence of any ovarian cysts. In anovulatory patients, a withdrawal bleeding was induced with the use of oral dydrogesteron (10 mg daily for 5 days) unless a baseline scan had shown an endometrial thickness of <5 mm. All patients received 150 IU hmg (Menopur; Ferring Pharmaceuticals) or highly purified human FSH (Fostimon, IBSA) daily for 3 days, started either on day 3 after menstrual periods or withdrawal bleeding or on the day of the baseline scan (in anovulatory patients with thin baseline endometrium). A second ultrasound scan was performed between days 6 and 8 of the IVM treatment cycle. When the endometrial thickness was >5 mm and there was no follicle >12 mm diameter, transvaginal oocyte retrieval was scheduled on the next day. No hcg trigger was administered. Oocyte retrieval was performed with a single-lumen 17-gauge needle (K-OPS-1230-VUB; Cook Medical) at an aspiration pressure of 70 mm Hg. No flushing was used. The patients received pethidine (1 mg/kg) and midazolam (2.5 mg) intramuscularly 60 minutes before egg retrieval and a mepivacaine paracervical block during the procedure. Follicular aspirates were filtered (Falcon 1060, 70 mm mesh size) and OCC were matured for 40 hours in MediCult IVM System (Origio). After denuding, mature oocytes were inseminated by ICSI as described previously (15). Oocytes and embryos were cultured individually in 25-mL medium droplets covered with mineral oil, from the day of ICSI (day 0) until day 3 or 5, in sequential Sage-cleavage and Sageblastocyst medium (Cooper Surgical). We offered patients an elective freeze all embryos approach with cancellation of the fresh embryo transfer and an ulterior embryo transfer in an artificial endometrial priming cycle if the endometrial thickness was <6 mm on the day of transfer in the IVM cycle. Only embryos with good morphology were selected for transfer and/or cryopreservation based on morphology in the morning of day 3 or day 5 (16). Embryo transfer was performed under ultrasound guidance using a soft catheter (K-Soft 5100; Cook). In case of a fresh embryo transfer, the choice between a single (SET) or double (DET) embryo transfer depended on the patient s age and the rank of trial, in accordance with Belgian legislation. Embryo vitrification was performed using closed CBS-VIT High Security (HS) straws (Cryo Bio system) in combination with DMSO-EG-S as the cryoprotectant (Irvine Scientific Freeze Kit), as previously described (17). Priming of the endometrium in an IVM treatment cycle consisted of transdermal E 2 gel (Oestrogel; Besins Healthcare; 2 mg administered three times a day, or five times a day if the endometrial thickness was <8 mm on the final ultrasound scan before oocyte retrieval) initiated on the day before oocyte retrieval. On the day of oocyte retrieval, treatment with intravaginal micronized P suppositories (200 mg three times a day; Utrogestan, Besins Healthcare) was started. Administration of E 2 and P was continued until a pregnancy test was performed and was continued until 7 weeks of gestation if the pregnancy test was positive. Vitrified/warmed embryos were transfered into an artificial endometrial priming cycle, initiated at menstruation after the IVM cycle. The endometrium was primed with transdermal E 2 gel (2 mg administered three times a day). Cycling patients were down-regulated with a GnRH agonist, buserelin (Suprefact; Aventis Pharma), in a dose of 600 mg daily, administered by nasal spray. When an endometrial thickness of R6 mm was reached, luteal support was started using intravaginal micronized P suppositories (200 mg three times a day), and transfer of one or two embryos was scheduled 3 or 5 days later. Outcome Parameters A normal rise in serum hcg on two consecutive occasions from 11 days after transfer onward indicated a pregnancy. The implantation rate represents the ratio between the number of gestational sacs and the total number of embryos transfered. A clinical pregnancy is a pregnancy with an intrauterine gestational sac seen at transvaginal ultrasound scan R5 weeks after embryo transfer (18). Statistical Analysis Data were analyzed in SPSS 19.0 statistical software. For categorical variables, the chi-square test or Fisher s exact test was used as appropriate. Non-categorical variables (age, body mass index [BMI], antimullerian hormone [AMH], and number of embryos transfered] were compared with the t test or the Mann Whitney test, depending on the normality of their distribution. Statistical significance was accepted when P<.05. RESULTS Thirty-four consecutive patients with PCOS, of whom 21 had amenorrhoea and 13 had oligo-ovulatory PCOS (19), and 5 consecutive patients with ultrasound-only PCO and regular cycles, underwent 73 oocyte retrievals in total. The number of immature GVoocytes, and maturation, fertilization, and cleavage rates are presented in Table 1. In 17 cycles, a dominant follicle of >12 mm diameter was noted on the day of oocyte retrieval. These cycles were not canceled; mean number of collected COC in these cycles ( ), maturation rate (59.4%), fertilization rate (74,7%), and cycle outcome did not differ significantly from those in cycles with no dominant follicle. In 20 IVM cycles, no embryo transfer occurred; of these, in 12 IVM cycles no embryo was available for transfer because no oocytes were retrieved (2/12 cycles) or because embryo development was suboptimal (10/12 cycles). Complete failure of maturation or fertilization occurred in none of the cycles. In eight IVM cycles, endometrium thickness was <6 mm on day 3 after intracytoplasmic sperm injection (ICSI) and therefore elective vitrification of all available IVM embryos of good morphology was performed. A fresh transfer of one or two cleavage-stage embryos occurred in 53 IVM cycles, with a mean number of 1.36 transfered embryos. Embryos generated after elective vitrification (eight IVM cycles) and supernumerary embryos generated in cycles with fresh embryo transfer (11 IVM cycles) were warmed in one or two ulterior artificial cycles. Twenty-five artificial endometrial priming cycles ensued. Baseline patient characteristics did not significantly differ among fresh and vitrified-warmed cycles (Table 2). In 12% (3/25) of the artificial cycles there was no embryo transfer owing to failed embryo survival after warming (Table 3). In 22 Fertility and Sterility â 861

3 TABLE 1 Fresh IVM cycle characteristics in PCO and PCOS. Total OCC retrieved 1,216 Total follicles punctured Retrieved OCC (mean SD) Mean serum estradiol level on the day of final US scan (pg/ml) Mean serum estradiol level on the day of oocyte retrieval (pg/ml) Maturation rate (%) 55.2 (500/906) Fertilization rate (%) 63.4 (316/500) Cleavage rate (%) 98.7 (312/316) Good-quality embryos (van Royen 47.5 (150/316) et al., 1999) Note: PCO ¼ polycystic ovaries; PCOS ¼ polycystic ovary syndrome; OCC ¼ oocyte-cumulus-complex. cycles, a transfer of vitrified-warmed transfer of IVM embryos was performed, with a mean number of 1.45 transfered embryos; the IVM embryo survival rate after warming was 78%. In nine cycles, vitrified-warmed ET was done after elective freezing of all embryos of good morphology. In 13 cycles, vitrified-warmed transfer of spare IVM embryos was done after a negative pregnancy test after a fresh IVM embryo transfer. Overall, fresh embryo transfer yielded a positive pregnancy test in 13.2% (7/53) per embryo transfer; the implantation rate was 6.9% (5/72) and the clinical pregnancy rate 9.4% (5/53) per embryo transfer. Two pregnancies were ectopic. Significantly better results were obtained with vitrified-warmed embryo transfer in an artificial cycle: This approach resulted in a positive pregnancy test in 40.9% (9/22) per embryo transfer (P¼.008); the implantation rate was 21.9% (7/32; P¼.043) and the clinical pregnancy rate 31.8% (7/ 22; P¼.033). Two patients delivered a healthy girl each, and four singleton pregnancies one twin pregnancy were ongoing at the time of writing. Two patients had a miscarriage (Table 3). Table 4 summarizes the comparative clinical outcomes of fresh and vitrified-warmed IVM embryo transfer. DISCUSSION The present study demonstrates for the first time that in a non hcg-primed IVM system, vitrified-warmed embryo transfer may perform better than fresh embryo transfer. TABLE 2 Baseline patient characteristics and IVM cycle parameters. Fresh Frozen P value Age (y) 28.3 (4.1) 27.8 (4.2).640 BMI (kg/m 2 ) 22.6 (9.4) 27 (5.3).058 AMH (ng/ml) 10.9 (10.2) 13.1 (13.1).583 No. of embryos transfered 1.36 (0.48) 1.45 (0.51).440 Note: Values represent mean and SD values. BMI ¼ body mass index; AMH ¼ antim ullerian hormone. TABLE 3 Outcome of artificial endometrial priming cycle. No. of artificial cycles 25 No. of frozen embryos 51 Embryo survival rate after warming (%) 71.1 (32/45) No. of vitrified-warmed embryos transferred No. of cycles without embryo transfer (%) 3 (11.5%) Positive pregnancy test (%) 40.9 (9/22) Implantation rate (%) 21.9 (7/32) Clinical pregnancy rate (%) 31.8 (7/22) Multiple pregnancies per transfered 4.5 (1/22) cycle (%) Miscarriage per transfered cycle (%) 9 (2/22) In a young patient with PCOS or ultrasound-only PCO, the risk to develop OHSS after controlled ovarian stimulation (COS) can be up to 10% (20, 21), and IVM is the only current assisted reproduction technology (ART) method than can eradicate the risk of OHSS, although GnRH agonist triggering in GnRH antagonist cycles is also an emerging approach to markedly decrease the risk of OHSS (22). In spite of clear advantages of IVM over COS in terms of patient-friendliness and cost of medication, conventional hormonedriven ART with in vivo oocyte maturation is still superior to IVM treatment regarding clinical outcomes. So far, there are no randomized controlled trials comparing IVM and conventional ART in women with PCOS (23). Fertility centers with a long-standing IVM experience generally perform better, and hcg priming may lead to improved pregnancy rates in part because small follicles will yield up to 20% in vivo matured MII oocytes surrounded by expanded cumulus cells at the moment of retrieval (24). Priming with hcg may also have a beneficial effect on the endometrium either directly or indirectly by supporting steroidogenesis. In the IVM system described here, no hcg trigger was administered before oocyte retrieval and oocyte maturation occurred purely in vitro, resulting in a homogenous cohort of mature oocytes. The clinical pregnancy rate (CPR) after fresh embryo transfer in the series of 53 cycles reported here is 9.4%. This figure is much lower than that reported by S oderstr om-anttila et al. in a small series of 17 embryo transfers in women with PCOS (CPR 52.9%) (25) and that of Zhao et al. (CPR 40%) (26), where more than three embryos were transfered on average. Although these favorable outcomes have not been repeated by other groups using TABLE 4 Comparative clinical outcomes of fresh and vitrifiedwarmed IVM embryo transfer. Fresh Vitrifiedwarmed P value Clinical 5/53 (9.4%) 7/22 (31.8%).033 pregnancy rate Positive hcg 7/53 (13.2%) 9/22 (40.9%).008 Implantation rate 5/72 (6.9%) 7/32 (21.9%).043 Note: Values represent numbers and percentages. 862 De Vos et al. Non hcg-primed IVM in PCO and PCOS Vol. 96, No. 4, October 2011

4 a non hcg-primed IVM system in PCOS, the important variability of reported pregnancy rates after IVM remains a source of concern. Since patients with PCO constitute a very heterogenous population, we suggest that differences in patient characteristics influencing estrogen receptor activity in the endometrium, such as androgens and members of the IGF system, may underlie the observed differences in outcome after fresh embryo transfer in IVM cycles. Furthermore, IVM outcome may be strongly influenced by differences in endometrial priming and luteal phase support protocols. In countries with a restrictive embryo transfer policy, government regulations do not generally allow fertility centers to transfer a higher number of embryos in IVM treatment cycles than in conventional ART cycles to compensate for the relatively lower implantation rate in IVM cycles (27). The divergence of clinical outcomes after IVM compared with classic IVF/ICSI in these centers can therefore be even larger, and ART clinicians may be discouraged by the rather modest pregnancy rates after IVM and fresh embryo transfer. Because endometrium thickness in IVM cycles can be suboptimal despite endometrial priming, embryo transfer is sometimes canceled and IVM-generated embryos are cryopreserved on purpose (2, 11). Although poor results have been reported using the slow-cooling method to freeze cleavage-stage embryos produced from IVM cycles (13), high survival rates and pregnancy rates have been observed using the method of vitrification (11, 28, 29). In the patient cohort presented here, we observed significantly improved pregnancy rates with vitrified-warmed embryo transfer in artificial cycles after IVM treatment in patients with PCO/PCOS without hcg priming compared with fresh embryo transfer. This result confirms the good results obtained by others and enables us to propose IVM plus vitrification as an attractive policy to enhance the outcomes after IVM in a system without hcg priming. Caution is needed regarding the safety of this approach: Despite reassuring neonatal outcomes after transfer of vitrified embryos and conventional ART, there is still a lack of neonatal data from follow-up studies after IVM pregnancies with vitrified embryos. Nevertheless, our results suggest that segmentation of IVM treatment into a cycle for oocyte retrieval and embryo development and a subsequent cycle for embryo transfer in a receptive endometrium may be an appealing approach. This method completely eliminates the risk of OHSS and allows more time for the endometrium to proliferate and undergo secretory changes. However, the methodology used in this study has limitations, because this was an observational study testing a novel strategy in IVM treatment. Therefore, the favorable results of vitrified-warmed IVM embryo transfer need confirmation in a prospective randomized controlled trial. In conclusion, this new approach shows good clinical outcomes of IVM in patients with PCOS and PCO without hcg priming, when embryos generated after IVM are cryopreserved by vitrification, warmed, and transfered in an artificial cycle. This policy could enhance the potential of IVM and could be a valuable method to increase the modest outcomes after fresh embryo transfer. It is imperative to test this model of treatment segmentation in IVM through a prospective randomized study comparing the outcomes after fresh embryo transfer and vitrified-warmed transfer. Acknowledgments: The authors thank the clinical embryologists, laboratory technicians, and nurses of the Center for Reproductive Medicine. REFERENCES 1. Edwards RG. Maturation in vitro of mouse, sheep, cow, pig, rhesus monkey and human ovarian oocytes. Nature 1965;208: Son WY, Tan SL. Laboratory and embryological aspects of hcg-primed in vitro maturation cycles for patients with polycystic ovaries. Hum Reprod Update 2010;16: Chian RC, Buckett WM, Tulandi T, Tan SL. Prospective randomized study of human chorionic gonadotrophin priming before immature oocyte retrieval from unstimulated women with polycystic ovarian syndrome. Hum Reprod 2000;15: Willis DW, Watson H, Mason HD, Galea R, Brincat M, Franks S. Premature response to luteinizing hormone of granulosa cells from anovulatory women with polycystic ovary syndrome: relevance to mechanism of anovulation. J Clin Endocrinol Metab 1998;83: Yang SH, Son WY, Yoon SH, Ko Y, Lim JH. Correlation between in vitro maturation and expression of LH receptor in cumulus cells of the oocytes collected from PCOS patients in hcg-primed IVM cycles. Hum Reprod 2005;20: Fadini R, Dal Canto MB, Mignini Renzini M, Brambillasca F, Comi R, Fumagalli D, et al. Effect of different gonadotrophin priming on IVM of oocytes from women with normal ovaries: a prospective randomized study. Reprod Biomed Online 2009;19: Albertini DF, Combelles CM, Benecchi E, Carabatsos MJ. Cellular basis for paracrine regulation of ovarian follicle development. Reproduction 2001;121: Suikkari AM, Tulppala M, Tuuri T, Hovatta O, Barnes F. Luteal phase start of low-dose FSH priming of follicles results in an efficient recovery, maturation and fertilization of immature human oocytes. Hum Reprod 2000;15: Cha KY, Koo JJ, Ko JJ, Choi DH, Han SY, Yoon TK. Pregnancy after in vitro fertilization of human follicular oocytes collected from non stimulated cycles, their culture in vitro and their transfer in a donor oocyte program. Fertil Steril 1991;55: Holzer H, Scharf E, Chian RC, Demirtas E, Buckett W, Tan SL. In vitro maturation of oocytes collected from unstimulated ovaries for oocyte donation. Fertil Steril 2007;88: Son WY, Chung JT, Gidoni Y, Holzer H, Levin D, Chian RC, et al. Comparison of survival rate of cleavage stage embryos produced from in vitro maturation cycles after slow freezing and after vitrification. Fertil Steril 2009;92: Shalom-PazE, Almog B, ShehataF, HuangJ, HolzerH, Chian RC, et al. Fertility preservation for breast-cancer patients using IVM followed by oocyte or embryo vitrification. Reprod Biomed Online 2010;21: Rotterdam ESHRE/ASRM-Sponsored PCOS Consensus Workshop Group. Revised 2003 consensus on diagnostic criteria and long-term health risks related to polycystic ovary syndrome. Fertil Steril 2004;81: Broekmans FJ, Knauff EA, Valkenburg O, Laven JS, Eijkemans MJ, Fauser BC. PCOS according to the Rotterdam consensus criteria: change in prevalence among WHO-II anovulation and association with metabolic factors. BJOG 2006;113: Joris H, Nagy Z, van de Velde H, De Vos A, van Steirteghem A. Intracytoplasmic sperm injection: laboratory set-up and injection procedure. Hum Reprod 1998;13: van Royen E, Mangelschots K, de Neubourg D, Valkenburg M, van de Meerssche M, Ryckaert G, et al. Characterization of a top quality embryo, a step toward single-embryo transfer. Hum Reprod 1999;14: van Landuyt L, Verpoest W, Verheyen G, de Vos A, van de Velde H, Liebaers I, et al. Closed blastocyst vitrification of biopsied embryos: evaluation of 100 consecutive warming cycles. Hum Reprod 2011;26: Zegers-Hochschild F, Adamson GD, de Mouzon J, Ishihara O, Mansour R, Nygren K, et al. International Committee for Monitoring Assisted Reproductive Technology (ICMART) and the World Health Organization (WHO) revised glossary of ART terminology, Fertil Steril 2009;92: Burgers JA, Fong SL, Louwers YV, Valkenburg O, de Jong FH, Fauser BC, et al. Oligoovulatory and anovulatory cycles in women with polycystic ovary syndrome (PCOS): what s the difference? J Clin Endocrinol Metab 2010;95:E MacDougall MJ, Tan SL, Balen A, Jacobs HS. A controlled study comparing patients with and without polycystic ovaries undergoing in-vitro fertilization. Hum Reprod 1993;8: Brinsden PR, Wada I, Tan SL, Balen A, Jacobs HS. Diagnosis, prevention and management of ovarian hyperstimulation syndrome. Br J Obstet Gynaecol 1995;102: Humaidan P, Kol S,Papanikolaou EG. GnRH agonist for triggering of final oocyte maturation: time for a change of practice? Hum Reprod Update 2011;17: Siristatidis CS, Maheshwari A, Bhattacharya S. Invitro maturation in sub fertile women with polycystic ovarian syndrome undergoing assisted reproduction. Cochrane Database Syst Rev 2009;(1):CD Fertility and Sterility â 863

5 24. Son WY, Chung JT, Demirtas E, Holzer H, Sylvestre C, Buckett W, et al. Comparison ofin-vitro maturation cycles with and without in-vivo matured oocytes retrieved. Reprod Biomed Online 2008;17: S oderstr om-anttila V, M akinen S, Tuuri T, Suikkari AM. Favourable pregnancy results with insemination of in vitro matured oocytes from unstimulated patients. Hum Reprod 2005;20: Zhao JZ, Zhou W, Zhang W, Ge HS, Huang XF, Lin JJ. In vitro maturation and fertilization of oocytes from unstimulated ovaries in infertile women with polycystic ovary syndrome. Fertil Steril 2009;91: Chian RC. In-vitro maturation of immature oocytes for infertile women with PCOS. Reprod Biomed Online 2004;8: Lee SY, Son WY, Yoon SH, Lim JH. Clinical-pregnancy outcome after vitrification of blastocysts produced from in vitro maturation cycles. Fertil Steril 2007;88: Zech N, Lopez J, Frias P, Leroy F, Vanderzwalmen P. In vitro maturation (IVM) of oocytes: replacement of developing embryos in a fresh or vitrified cycle? Hum Reprod 2009;24(Suppl 1):i De Vos et al. Non hcg-primed IVM in PCO and PCOS Vol. 96, No. 4, October 2011

6 SUPPLEMENTAL FIGURE 1 Flowchart describing the interventions associated with IVM treatment in the study cohort. Fertility and Sterility â 864.e1