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RBMOnline - Vol 7. No 3. 313–318 Reproductive BioMedicine Online; www.rbmonline.com/Article/1024 on web 6 August 2003
Article Reproductive outcome of polycystic ovarian syndrome patients treated with GnRH antagonists and recombinant FSH for IVF/ICSI Dr Kolibianakis obtained his specialization in Obstetrics and Gynaecology in 2000 and since then he has been a staff specialist at the Centre for Reproductive Medicine of the Dutch-Speaking Brussels Free University. His particular research interest is in endocrinology of the antagonist cycle.
Dr Efstratios Kolibianakis Efstratios Kolibianakis, Kostantinos Zikopoulos, Carola Albano, Michel Camus, Herman Tournaye, Andre Van Steirteghem, Paul Devroey Centre for Reproductive Medicine, Dutch-Speaking Brussels Free University, Laarbeeklaan 101, 1090 Brussels, Belgium Correspondence: Fax: +32 2 4776660; e-mail: [email protected]
Abstract The purpose of this prospective study was to assess the reproductive outcome of patients with polycystic ovarian syndrome (PCOS) treated by in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) with recombinant FSH (rFSH) and gonadotrophin releasing hormone (GnRH) antagonists. One hundred and ten patients were evaluated. The starting dose of rFSH was 100 IU in 67 women with body mass index (BMI) ≤29 kg/m2 and 200 IU in 43 women with BMI >29 kg/m2. GnRH antagonist was started by the detection of a follicle of ≥15mm in ultrasound scan. A significantly lower ongoing pregnancy rate per oocyte retrieval (25.6% versus 46.7%, P = 0.04) and a higher occurrence of ovarian hyperstimulation syndrome (16.3% versus 3.0%, P = 0.03) was observed in the group of patients with BMI >29 kg/m2 as compared with the group of patients with BMI ≤29 kg/m2, respectively. In conclusion, in GnRH antagonist cycles a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH. Keywords: GnRH antagonists, ovarian stimulation, polycystic ovarian syndrome, recombinant follicle stimulating hormone
The need for suppressing endogenous gonadotrophins in patients with polycystic ovarian syndrome (PCOS) undergoing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is supported by the lower miscarriage rate achieved in the presence of pituitary down-regulation (Balen et al., 1993; Homburg et al., 1993).
Obesity plays a major role in the pathophysiology of PCOS (Gambineri, et al., 2002). Obese women with PCOS require more FSH for ovulation induction than non-obese subjects (Dale et al., 1993; Homburg et al., 1996). Moreover, in PCOS women treated by IVF/ICSI, obesity has been associated with gonadotrophin resistance, as shown by higher gonadotrophin requirement, a lower number of collected oocytes and lower peak oestradiol concentrations (Fedorcsak et al., 2001).
Down-regulation in PCOS patients treated with IVF/embryo transfer has so far been accomplished by using gonadotrophinreleasing hormone (GnRH) agonists. No information is currently available on the reproductive outcome in this group of patients after treatment with GnRH antagonists as during phase three comparative studies between GnRH agonists and GnRH antagonists, no PCOS patients were included.
The purpose of this study was to assess the reproductive outcome of PCOS patients treated with GnRH antagonists and recombinant FSH (rFSH). Two groups of patients were compared: PCOS patients with body mass index (BMI) ≤29 kg/m2 in whom stimulation was initiated with 100 IU of rFSH and PCOS patients with BMI >29 kg/m2 in whom stimulation was initiated with 200 IU of rFSH.
Introduction
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Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Materials and methods
Luteal supplementation
Patient population
The luteal phase was supplemented with vaginal administration of 600 mg natural micronized progesterone (Utrogestan®; Piette, Brussels, Belgium) in three separate doses, starting one day after oocyte retrieval and continued for 14 days (Schmidt et al., 2001).
One hundred and ten patients with PCOS treated by IVF/ICSI between April 2001 and September 2002 at the Centre for Reproductive Medicine of the Dutch-Speaking Brussels Free University were included in the study. Diagnosis of PCOS was confirmed by the presence of polycystic ovaries at ultrasound (Adams et al., 1985), in addition to oligomenorrhoea/amenorrhoea and/or hirsutism/acne (Homburg et al., 1993). Additional infertility factors besides PCOS included male infertility (n = 65) and tubal infertility (n = 5). Patients could participate in the study only once. The mean age of patients was 30.6 ± 0.4 years while the mean number of previous IVF/ICSI trials was 0.9 ± 0.1 BMI of >29 kg/m2 was present in 43 patients (mean BMI: 34.4 kg/m2) while in the remaining 67 patients BMI was ≤29 kg/m2 (mean BMI = 21.4 kg/m2). The choice of BMI cutoff ≤29 kg/m2 to define the two groups of PCOS patients was based on its previous use during phase three comparative studies between GnRH agonists and GnRH antagonists (Fluker et al., 2001).
Ovarian stimulation and type of ART Recombinant FSH (Puregon®, NV Organon, Oss, The Netherlands) was started on day 2 of the menstrual cycle at 100 IU per day in patients with BMI ≤29 kg/m2 and at 200 IU in patients with BMI >29 kg/m2. The dose of rFSH was increased by 50 IU at initiation of GnRH antagonist in both groups. After two days of antagonist administration, the dose of rFSH could be adjusted depending on the ovarian response as monitored via ultrasonography and serum oestradiol concentrations. GnRH antagonist ganirelix (Orgalutran; NV Organon, Oss, The Netherlands) 0.25 mg daily was started when ≥1 follicle of ≥15 mm was present after at least 5 days of rFSH stimulation in ultrasound and continued up to the day of human chorionic gonadotrophin (HCG) administration. If no follicle of ≥15 mm was present after 5 days of rFSH stimulation, a new ultrasound scan was requested after 48 h, or the next day if more than one follicle of 13 mm or 14 mm was already present. Antagonist was always started when the presence of a follicle ≥15 mm was confirmed by ultrasound examination. Blood for hormonal evaluations was taken on days 1 and 6 of stimulation and thereafter whenever ultrasound scan was performed. Ovulation induction was performed using 10,000 IU of HCG (Pregnyl, Organon, Oss, The Netherlands) when ≥3 follicles ≥17 mm diameter were present on ultrasound. Oocyte retrieval was carried out 36 h after HCG administration by transvaginal ultrasound-guided puncture of follicles. ICSI and IVF procedures have been described in detail previously (Van Steirteghem et al., 1993; Devroey et al., 1995). Two to three embryos were transferred on day 3 or day 5 after oocyte retrieval. Embryos were classified as top quality (score 1) medium quality (score 2) and low quality (score 3) as previously described (Staessen et al., 1992; Gardner and Schoolcraft, 1999). The mean score of the embryos transferred to each patient was used for the calculation of the mean quality score of all embryos transferred.
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Hormonal measurements Serum LH, FSH, HCG, oestradiol and progesterone concentrations were measured by means of the automated Elecsys immunoanalyser (Roche Diagnostics, Mannheim, Germany). Intra-assay and inter-assay coefficients of variation (CV) were <3% and <4% for LH, <3% and <6% for FSH, <5% and <7% for HCG, <5% and <10% for oestradiol and <3% and <5% for progesterone, respectively.
Outcome measures Ongoing implantation rate was calculated by dividing the number of gestational sacs with a fetal heartbeat at 12 weeks of gestation by the number of embryos transferred. Pregnancies progressing beyond the 12th week of gestation were considered ongoing.
Statistical analysis Fisher’s exact test was used to analyse nominal variables in the form of frequency tables. Normally distributed (Kolmogorov–Smirnov test with Lilliefors correction) metric variables were tested by the t-test for independent samples, while non-normally distributed metric variables were analysed by the Mann–Whitney U-test. Values are expressed as mean ± SEM, unless stated otherwise.
Results One hundred and three PCOS patients (93.6%) treated with rFSH and GnRH antagonists reached oocyte retrieval. The cycle was stopped in seven patients with BMI ≤29 kg/m2, as a result of poor response to ovarian stimulation (n = 6) or due to high risk of ovarian hyperstimulation syndrome (OHSS) (n = 1). No cancellations occurred in the group of patients with BMI >29 kg/m2. GnRH antagonist was started after a mean of 5.9 ± 0.1 days of rFSH stimulation, while a mean of 11.0 ± 0.2 days of rFSH stimulation was required for HCG administration. A mean of 14.2 ± 0.7 cumulus oocyte complexes were retrieved and 2.0 ± 0.1 embryos were transferred per patient. Thirty-nine ongoing pregnancies were obtained (37.9% per oocyte retrieval, 38.6% per embryo transfer), which resulted in a 23.6% ongoing implantation rate. A similar proportion of patients with BMI ≤29 kg/m2 and BMI >29 kg/m2 presented with only PCOS (31.3 versus 32.6%, respectively), with coexisting male factor infertility (64.2 versus 62.8%, respectively) or with tubal factor infertility (4.5 versus 4.7%, respectively). Patient characteristics and stimulation data in the two groups of PCOS patients compared appear in Table 1. In the group of patients with BMI ≤29 kg/m2, a significantly shorter
Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
P = 0.04) and a higher occurrence of OHSS (16.3 versus 3.0%, P = 0.03) was observed in the group of patients with BMI >29 kg/m2 as compared with the group of patients with BMI ≤29 kg/m2, respectively. The median duration of hospitalization due to OHSS in the group of patients with BMI >29 kg/m2 was 3.5 days (interquartile range 2 days). In addition, the group of patients with BMI ≤29 kg/m2 showed a tendency towards a higher ongoing implantation rate and a lower miscarriage rate in comparison to the group of patients with BMI >29 kg/m2.
interval from initiation of rFSH stimulation to GnRH antagonist administration was present. Moreover, these patients were 1.7 ± 0.7 years older than those with BMI >29 kg/m2 and had a lower number of follicles of ≥15 mm on the day of HCG administration as compared with the group of patients with BMI >29 kg/m2. The outcome of patients with PCOS treated by GnRH antagonists and rFSH is shown in Table 2. A significantly lower ongoing pregnancy rate per oocyte retrieval (25.6 versus 46.7%,
Table 1. Comparison of PCOS patients treated with rFSH and GnRH antagonists for IVF/ICSI. Characteristics
Female age (years) Previous IVF/ICSI trials FSH at initiation of stimulation (IU/l) Duration of stimulation before antagonist (days) Duration of rFSH stimulation (days) Total units of rFSH (IU) Oestradiol at HCG day (pg/ml) Progesterone at HCG day (ng/ml) LH at HCG day (IU/l) Number of follicles of ≥15mm at HCG daya Number of cumulus–oocyte –complexes Number of 2PN oocytes Fertilization rate (%) Number of embryos transferred Mean quality score of transferred embryos
BMI ≤29 kg/m2
BMI >29 kg/m2
Starting dose 100 IU
Starting dose 200 IU
31.3 ± 0.4 0.9 ± 0.1 6.4 ± 0.3
29.6 ± 0.6 0.9 ± 0.2 6.4 ± 0.5
0.01 0.93 0.42
5.6 ± 0.1
6.3 ± 0.2
0.01
11.0 ± 0.3
10.9 ± 0.4
0.66
1451 ± 71 2073 ± 166 1.1 ± 0.1
2481 ± 153 2116 ± 193 1.2 ± 0.1
0.001 0.66 0.20
1.3 ± 0.2 8.6 ± 0.5
1.5 ± 0.3 10.7 ± 0.6
0.51 0.01
13.5 ± 1.0
15.2 ± 1.4
0.14
7.0 ± 0.6 74.4 ± 2.9 2.0 ± 0.1
10.1 ± 1.0 78.6 ± 2.3 2.1 ± 0.1
0.01 0.54 0.70
1.9 ± 0.1
1.8 ± 0.1
0.54
P-value
PN = pronuclear. aNo difference was observed between the two groups in the number of follicles ≥11mm and ≥17mm on the day of HCG administration.
Table 2. Outcome of PCOS patients treated with GnRH antagonists and rFSH for IVF/ICSI. BMI ≤29 kg/m2
BMI >29 kg/m2
Starting dose 100 IU
Starting dose 200 IU
Ongoing pregnancy rate per oocyte retrieval Pregnancies (n) Percentage
28/60 (47.3)
11/43 (25.7)
0.04
Ongoing implantation rate Percentage
29.3 ± 4.8
19.0 ± 5.5
0.07
Miscarriage rate Pregnancies (n) Percentage
1/29 (3.4)
3/14 (21.4)
0.09
Ovarian hyperstimulation syndrome rate Pregnancies (n) Percentage
2/67 (3.0)
7/43 (16.3)
0.03
Outcome
P-value
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Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Discussion This study shows that in GnRH antagonist cycles, a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH. As far as is known, this is the first study evaluating the outcome of IVF/ICSI in PCOS patients treated with GnRH antagonists and rFSH. The higher starting dose of FSH applied to the group of patients with BMI >29 kg/m2 as compared with the group with BMI ≤29 kg/m 2 , aimed at minimizing the effect of the increased BMI in the duration of follicular phase. Indeed, as shown in Table 1, a similar duration of stimulation was observed between the two groups compared (10.9 ± 0.4 days versus 11.0 ± 0.3 days, respectively). Moreover, similar concentrations of oestradiol on the day of HCG administration and no difference in the number of cumulus–oocyte–complexes retrieved were observed in both BMI groups (Table 1). Under the current study design, the difference in ongoing pregnancy rate between the two groups compared might be attributed to the effect of BMI and/or the effect of the starting dose of rFSH used. However, a relationship between an increased starting dose of FSH and an adverse pregnancy outcome has not been established in antagonist cycles. Indirect data on this relationship are available at present only for non-PCOS patients. During phase-three comparative studies between agonists and antagonists, the highest pregnancy rate was observed in the North American trial (Fluker et al., 2001) in which stimulation started with the highest gonadotrophin dose as compared with the other four trials (Albano et al., 2000; Borm and Mannaerts, 2000; The Middle East Orgalutran Study Group, 2001; Olivennes et al., 2000). Moreover such a relationship has not been shown for GnRH agonist cycles (Wikland et al., 2001). It is thus likely that the significantly lower ongoing pregnancy rate observed in the group of patients with high BMI might be attributed mainly to the increased obesity itself and, to a lesser degree, to the different starting dose of gonadotrophin. Obesity can affect gonadotrophin pharmacokinetics (Fridstrom et al., 1997; Mannaerts et al., 1993), leptin concentrations and metabolism of sex steroids (Azziz, 1989) and has been associated with an adverse pregnancy outcome (Norman and Clark, 1998; Franks, 2003). In addition, it is related to increased insulin resistance/hyperinsulinaemia. Insulin enhances androgen production by theca cells and the elevated insulin in PCOS patients is believed to be the cornerstone of the resulting ovarian dysfunction (Utiger, 1996). Although both lean and obese women with PCOS show evidence of decreased insulin sensitivity, insulin resistance accompanied by compensatory hyperinsulinaemia is most marked when there is an interaction between obesity and the syndrome (Dunaif et al., 1987, 1989).
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Whatever the mechanism involved, the significantly lower ongoing pregnancy rate in the group of patients with BMI >29 kg/m2 does not appear to be related to the number or the
quality of the embryos transferred in PCOS patients which were similar between the two groups compared. Furthermore, PCOS patients with BMI >29 kg/m2 had significantly more 2PN oocytes and were significantly younger than those with BMI ≤29 kg/m2, which makes an embryonic factor as a cause for a worse reproductive outcome in patients with BMI >29 kg/m2 less likely. However, a longer interval from initiation of rFSH stimulation until initiation of GnRH antagonist (by a follicle of ≥15 mm in ultrasound scan) was required in the patients with BMI >29 kg/m2, despite a higher starting dose of rFSH. Sixty-eight per cent of the patients with BMI ≤29 kg/m2 started GnRH antagonist on day 6 of stimulation compared with 40% of the patients in the group with BMI >29kg/m2 (P = 0.009). A delayed antagonist initiation when there is no follicle of ≥15 mm after 5 days of rFSH stimulation, has been shown to result in a lower implantation rate as compared with fixed initiation after 5 days in non-PCOS patients (Kolibianakis et al., 2003). The fact that in the group with BMI >29 kg/m2 significantly more patients started GnRH antagonist after more than 5 days of rFSH stimulation might explain the difference observed in ongoing pregnancy rates between the two BMI groups. It may be worth evaluating the effect of earlier antagonist administration in this group of PCOS patients with BMI >29 kg/m2. Moreover, the use of metformin in PCOS patients undergoing IVF should also be considered (Stadtmauer, 2002). Considering the difference observed in OHSS incidence between the two groups compared, it could be supported that this is a consequence of the higher dose of FSH used in the group of patients with BMI >29 kg/m2 which has led to significantly more follicles ≥15 mm being present on the day of HCG administration and thus to an increased risk of developing OHSS. Although this might be true, no difference was observed in the total number of follicles ≥11 mm or the number of follicles ≥17 mm on the day of HCG. In addition, similar oestradiol concentrations were also present between the two groups compared on the same day. Moreover, there appears to be no linear positive relationship between OHSS occurrence and gonadotrophin quantity used for stimulation (Delvigne and Rozenberg, 2002). On the contrary, patients suffering from OHSS often receive much less gonadotrophin than others (Navot et al., 1988; Smitz et al., 1990; Delvigne et al., 1993; Enskog et al., 1999). It is possible, however, that the significantly lower age of patients with BMI >29 kg/m2 might also be involved in the difference in OHSS occurrence (Golan et al., 1988; Navot et al., 1988). Nevertheless patients admitted in both groups due to OHSS did not require prolonged hospitalization. At least in patients with BMI >29 kg/m2 it is probably worth evaluating the use of GnRH agonists as a signal for triggering final oocyte maturation (Felberbaum and Diedrich, 2003; Howles, 2002; Olivennes, 2002; Olivennes et al., 2002). In conclusion, a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH, when GnRH antagonists are used for inhibition of premature LH surge.
Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Acknowledgements The authors would like to thank Mrs Julie Deconick for correcting the manuscript. This work is supported by grants from the Fund for Scientific Research, Flanders, Belgium.
References Adams J, Franks S, Polson DW et al. 1985 Multifollicular ovaries: clinical and endocrine features and response to pulsatile gonadotropin releasing hormone. Lancet 2, 1375–1379. Albano C, Felberbaum RE, Smitz J et al. 2000 Ovarian stimulation with HMG: results of a prospective randomized phase III European study comparing the luteinizing hormone-releasing hormone (LHRH)-antagonist cetrorelix and the LHRH-agonist buserelin. European Cetrorelix Study Group. Human Reproduction 15, 526–531. Azziz R 1989 Reproductive endocrinologic alterations in female asymptomatic obesity. Fertility and Sterility 52, 703–725. Balen AH, Tan SL, MacDougall J et al. 1993 Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin. Human Reproduction 8, 959–964. Borm G, Mannaerts B 2000 Treatment with the gonadotrophinreleasing hormone antagonist ganirelix in women undergoing ovarian stimulation with recombinant follicle stimulating hormone is effective, safe and convenient: results of a controlled, randomized, multicentre trial. The European Orgalutran Study Group. Human Reproduction 15, 1490–1498. Dale O, Tanbo T, Lunde O et al. 1993 Ovulation induction with lowdose follicle-stimulating hormone in women with the polycystic ovary syndrome. Acta Obstetrica Gynecologica Scandinavica 72, 43–46. Delvigne A, Rozenberg S 2002 Epidemiology and prevention of ovarian hyperstimulation syndrome (OHSS): a review. Human Reproduction Update 8, 559–577. Delvigne A, Demoulin A, Smitz J et al. 1993 The ovarian hyperstimulation syndrome in in-vitro fertilization: a Belgian multicentric study. I. Clinical and biological features. Human Reproduction 8, 1353–1360. Devroey P, Tjandraprawira K, Mannaerts B et al. 1995 A randomized, assessor-blind, group-comparative efficacy study to compare the effects of Normegon and Metrodin in infertile female patients undergoing in-vitro fertilization. Human Reproduction 10, 332–337. Dunaif A, Graf M, Mandeli J et al. 1987 Characterization of groups of hyperandrogenic women with acanthosis nigricans, impaired glucose tolerance, and/or hyperinsulinemia. Journal of Clinical Endocrinology and Metabolism 65, 499–507. Dunaif A, Segal KR, Futterweit W et al. 1989 Profound peripheral insulin resistance, independent of obesity, in polycystic ovary syndrome. Diabetes 38, 1165–1174. Enskog A, Henriksson M, Unander M et al. 1999 Prospective study of the clinical and laboratory parameters of patients in whom ovarian hyperstimulation syndrome developed during controlled ovarian hyperstimulation for in-vitro fertilization. Fertility and Sterility 71, 808–814. Fedorcsak P, Dale PO, Storeng R et al. 2001 The impact of obesity and insulin resistance on the outcome of IVF or ICSI in women with polycystic ovarian syndrome. Human Reproduction 16, 1086–1091. Felberbaum RE, Diedrich K 2003 Gonadotrophin-releasing hormone antagonists: will they replace the agonists? Reproductive BioMedicine Online 6, 43–53. Fluker M, Grifo J, Leader A et al. 2001 Efficacy and safety of ganirelix acetate versus leuprolide acetate in women undergoing controlled ovarian hyperstimulation. Fertility and Sterility 75, 38–45. Franks S 2003 Gonadotrophin regimens and oocyte quality in women
with polycystic ovaries. Reproductive BioMedicine Online 6, 181–184. Fridstrom M, Sjoblom P, Pousette A, Hillensjo T 1997 Serum FSH levels in women with polycystic ovary syndrome during ovulation induction using down-regulation and urofollitropin. European Journal of Endocrinology 136, 488–492. Gambineri A, Pelusi C, Vicennati V et al. 2002 Obesity and the polycystic ovary syndrome. International Journal of Obesity and Related Metabolic Disorders 26, 883–896. Gardner DK, Schoolcraft WB 1999 In-vitro culture of human blastocysts. In: Jansen R, Mortimer D (eds), Towards Reproductive Certainty: Infertility and Genetics Beyond 1999. Parthenon Press, Carnforth, UK, pp. 377–388. Golan A, Ron-El R, Herman A et al. 1988 Ovarian hyperstimulation syndrome following D-Trp-6 luteinizing hormone-releasing hormone microcapsules and menotropin for in vitro fertilization. Fertility and Sterility 50, 912–916. Homburg R, Levy T, Berkovitz D et al. 1993 Gonadotropin-releasing hormone agonist reduces the miscarriage rate for pregnancies achieved in women with polycystic ovarian syndrome. Fertility and Sterility 59, 527–531. Homburg R, Orvieto R, Bar-Hava I et al. 1996 Serum levels of insulin-like growth factor-1, IGF binding protein-1 and insulin and the response to human menopausal gonadotrophins in women with polycystic ovary syndrome. Human Reproduction 11, 716–719. Howles CM 2002 The place of gonadotrophin-releasing hormone antagonists in reproductive medicine. Reproductive BioMedicine Online 4, 64–71. Kolibianakis EM, Albano C, Kahn J et al. 2003 Exposure to high levels of luteinizing hormone and estradiol in the early follicular phase of gonadotropin-releasing hormone antagonist cycles is associated with a reduced chance of pregnancy. Fertility and Sterility 79, 873–880. Mannaerts B, Shoham Z, Schoot D et al. 1993 Single-dose pharmacokinetics and pharmacodynamics of recombinant human follicle-stimulating hormone (Org 32489®) in gonadotropindeficient volunteers. Fertility and Sterility 59, 108–114. Navot D, Relou A, Birkenfeld A et al. 1988 Risk factors and prognostic variables in the ovarian hyperstimulation syndrome. American Journal of Obstetrics and Gynecology 159, 205–210. Norman RJ, Clark AM 1998 Obesity and reproductive disorders: a review. Reproduction, Fertility and Development 10, 55–63. Olivennes F 2002 GnRH antagonists: do they open new pathways to safer treatment in assisted reproductive techniques? Reproductive BioMedicine Online 5, 20–25. Olivennes F, Belaisch-Allart J, Emperaire JC et al. 2000 Prospective, randomized, controlled study of in-vitro fertilization- embryo transfer with a single dose of a luteinizing hormone-releasing hormone (LH-RH) antagonist (cetrorelix) or a depot formula of an LH-RH agonist (triptorelin). Fertility and Sterility 73, 314–320. Olivennes F, Cunha-Filho JS, Fanchin R et al. 2002 The use of GnRH antagonists in ovarian stimulation. Human Reproduction Update 8, 279–290. Schmidt, KL, Ziebe S, Popovic B et al. 2001 Progesterone supplementation during early gestation after in vitro fertilization has no effect on the delivery rate. Fertility and Sterility 75, 337–341. Smitz J, Camus M, Devroey P et al. 1990 Incidence of severe ovarian hyperstimulation syndrome after GnRH agonist/HMG superovulation for in-vitro fertilization. Human Reproduction 5, 933–937. Stadtmauer LA, Toma SK, Riehl RM et al. 2002 Impact of metformin therapy on ovarian stimulation and outcome in ‘coasted’ patients with polycystic ovary syndrome undergoing invitro fertilization. Reproductive BioMedicine Online 5, 112–116. Staessen C, Camus M, Bollen N et al. 1992 The relationship between embryo quality and the occurrence of multiple pregnancies. Fertility and Sterility 57, 626–630.
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The Middle East Orgalutran Study Group 2001 Comparable clinical outcome using the GnRH antagonist ganirelix or a long protocol of the GnRH agonist triptorelin for the prevention of premature LH surges in women undergoing ovarian stimulation. Human Reproduction 16, 644–651. Utiger RD 1996 Insulin and the polycystic ovary syndrome. New England Journal of Medicine 335, 657–658. Van Steirteghem AC, Nagy Z, Joris H et al. 1993 High fertilization
318
and implantation rates after intracytoplasmic sperm injection. Human Reproduction 8, 1061–1066. Wikland, M, Bergh C, Borg K et al. 2001 A prospective, randomized comparison of two starting doses of recombinant FSH in combination with cetrorelix in women undergoing ovarian stimulation for IVF/ICSI. Human Reproduction 6, 1676–1681.
Received 28 May 2003; refereed 26 June 2003; accepted 14 July 2003.
Article Reproductive outcome of polycystic ovarian syndrome patients treated with GnRH antagonists and recombinant FSH for IVF/ICSI Dr Kolibianakis obtained his specialization in Obstetrics and Gynaecology in 2000 and since then he has been a staff specialist at the Centre for Reproductive Medicine of the Dutch-Speaking Brussels Free University. His particular research interest is in endocrinology of the antagonist cycle.
Dr Efstratios Kolibianakis Efstratios Kolibianakis, Kostantinos Zikopoulos, Carola Albano, Michel Camus, Herman Tournaye, Andre Van Steirteghem, Paul Devroey Centre for Reproductive Medicine, Dutch-Speaking Brussels Free University, Laarbeeklaan 101, 1090 Brussels, Belgium Correspondence: Fax: +32 2 4776660; e-mail: [email protected]
Abstract The purpose of this prospective study was to assess the reproductive outcome of patients with polycystic ovarian syndrome (PCOS) treated by in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) with recombinant FSH (rFSH) and gonadotrophin releasing hormone (GnRH) antagonists. One hundred and ten patients were evaluated. The starting dose of rFSH was 100 IU in 67 women with body mass index (BMI) ≤29 kg/m2 and 200 IU in 43 women with BMI >29 kg/m2. GnRH antagonist was started by the detection of a follicle of ≥15mm in ultrasound scan. A significantly lower ongoing pregnancy rate per oocyte retrieval (25.6% versus 46.7%, P = 0.04) and a higher occurrence of ovarian hyperstimulation syndrome (16.3% versus 3.0%, P = 0.03) was observed in the group of patients with BMI >29 kg/m2 as compared with the group of patients with BMI ≤29 kg/m2, respectively. In conclusion, in GnRH antagonist cycles a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH. Keywords: GnRH antagonists, ovarian stimulation, polycystic ovarian syndrome, recombinant follicle stimulating hormone
The need for suppressing endogenous gonadotrophins in patients with polycystic ovarian syndrome (PCOS) undergoing in-vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) is supported by the lower miscarriage rate achieved in the presence of pituitary down-regulation (Balen et al., 1993; Homburg et al., 1993).
Obesity plays a major role in the pathophysiology of PCOS (Gambineri, et al., 2002). Obese women with PCOS require more FSH for ovulation induction than non-obese subjects (Dale et al., 1993; Homburg et al., 1996). Moreover, in PCOS women treated by IVF/ICSI, obesity has been associated with gonadotrophin resistance, as shown by higher gonadotrophin requirement, a lower number of collected oocytes and lower peak oestradiol concentrations (Fedorcsak et al., 2001).
Down-regulation in PCOS patients treated with IVF/embryo transfer has so far been accomplished by using gonadotrophinreleasing hormone (GnRH) agonists. No information is currently available on the reproductive outcome in this group of patients after treatment with GnRH antagonists as during phase three comparative studies between GnRH agonists and GnRH antagonists, no PCOS patients were included.
The purpose of this study was to assess the reproductive outcome of PCOS patients treated with GnRH antagonists and recombinant FSH (rFSH). Two groups of patients were compared: PCOS patients with body mass index (BMI) ≤29 kg/m2 in whom stimulation was initiated with 100 IU of rFSH and PCOS patients with BMI >29 kg/m2 in whom stimulation was initiated with 200 IU of rFSH.
Introduction
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Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Materials and methods
Luteal supplementation
Patient population
The luteal phase was supplemented with vaginal administration of 600 mg natural micronized progesterone (Utrogestan®; Piette, Brussels, Belgium) in three separate doses, starting one day after oocyte retrieval and continued for 14 days (Schmidt et al., 2001).
One hundred and ten patients with PCOS treated by IVF/ICSI between April 2001 and September 2002 at the Centre for Reproductive Medicine of the Dutch-Speaking Brussels Free University were included in the study. Diagnosis of PCOS was confirmed by the presence of polycystic ovaries at ultrasound (Adams et al., 1985), in addition to oligomenorrhoea/amenorrhoea and/or hirsutism/acne (Homburg et al., 1993). Additional infertility factors besides PCOS included male infertility (n = 65) and tubal infertility (n = 5). Patients could participate in the study only once. The mean age of patients was 30.6 ± 0.4 years while the mean number of previous IVF/ICSI trials was 0.9 ± 0.1 BMI of >29 kg/m2 was present in 43 patients (mean BMI: 34.4 kg/m2) while in the remaining 67 patients BMI was ≤29 kg/m2 (mean BMI = 21.4 kg/m2). The choice of BMI cutoff ≤29 kg/m2 to define the two groups of PCOS patients was based on its previous use during phase three comparative studies between GnRH agonists and GnRH antagonists (Fluker et al., 2001).
Ovarian stimulation and type of ART Recombinant FSH (Puregon®, NV Organon, Oss, The Netherlands) was started on day 2 of the menstrual cycle at 100 IU per day in patients with BMI ≤29 kg/m2 and at 200 IU in patients with BMI >29 kg/m2. The dose of rFSH was increased by 50 IU at initiation of GnRH antagonist in both groups. After two days of antagonist administration, the dose of rFSH could be adjusted depending on the ovarian response as monitored via ultrasonography and serum oestradiol concentrations. GnRH antagonist ganirelix (Orgalutran; NV Organon, Oss, The Netherlands) 0.25 mg daily was started when ≥1 follicle of ≥15 mm was present after at least 5 days of rFSH stimulation in ultrasound and continued up to the day of human chorionic gonadotrophin (HCG) administration. If no follicle of ≥15 mm was present after 5 days of rFSH stimulation, a new ultrasound scan was requested after 48 h, or the next day if more than one follicle of 13 mm or 14 mm was already present. Antagonist was always started when the presence of a follicle ≥15 mm was confirmed by ultrasound examination. Blood for hormonal evaluations was taken on days 1 and 6 of stimulation and thereafter whenever ultrasound scan was performed. Ovulation induction was performed using 10,000 IU of HCG (Pregnyl, Organon, Oss, The Netherlands) when ≥3 follicles ≥17 mm diameter were present on ultrasound. Oocyte retrieval was carried out 36 h after HCG administration by transvaginal ultrasound-guided puncture of follicles. ICSI and IVF procedures have been described in detail previously (Van Steirteghem et al., 1993; Devroey et al., 1995). Two to three embryos were transferred on day 3 or day 5 after oocyte retrieval. Embryos were classified as top quality (score 1) medium quality (score 2) and low quality (score 3) as previously described (Staessen et al., 1992; Gardner and Schoolcraft, 1999). The mean score of the embryos transferred to each patient was used for the calculation of the mean quality score of all embryos transferred.
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Hormonal measurements Serum LH, FSH, HCG, oestradiol and progesterone concentrations were measured by means of the automated Elecsys immunoanalyser (Roche Diagnostics, Mannheim, Germany). Intra-assay and inter-assay coefficients of variation (CV) were <3% and <4% for LH, <3% and <6% for FSH, <5% and <7% for HCG, <5% and <10% for oestradiol and <3% and <5% for progesterone, respectively.
Outcome measures Ongoing implantation rate was calculated by dividing the number of gestational sacs with a fetal heartbeat at 12 weeks of gestation by the number of embryos transferred. Pregnancies progressing beyond the 12th week of gestation were considered ongoing.
Statistical analysis Fisher’s exact test was used to analyse nominal variables in the form of frequency tables. Normally distributed (Kolmogorov–Smirnov test with Lilliefors correction) metric variables were tested by the t-test for independent samples, while non-normally distributed metric variables were analysed by the Mann–Whitney U-test. Values are expressed as mean ± SEM, unless stated otherwise.
Results One hundred and three PCOS patients (93.6%) treated with rFSH and GnRH antagonists reached oocyte retrieval. The cycle was stopped in seven patients with BMI ≤29 kg/m2, as a result of poor response to ovarian stimulation (n = 6) or due to high risk of ovarian hyperstimulation syndrome (OHSS) (n = 1). No cancellations occurred in the group of patients with BMI >29 kg/m2. GnRH antagonist was started after a mean of 5.9 ± 0.1 days of rFSH stimulation, while a mean of 11.0 ± 0.2 days of rFSH stimulation was required for HCG administration. A mean of 14.2 ± 0.7 cumulus oocyte complexes were retrieved and 2.0 ± 0.1 embryos were transferred per patient. Thirty-nine ongoing pregnancies were obtained (37.9% per oocyte retrieval, 38.6% per embryo transfer), which resulted in a 23.6% ongoing implantation rate. A similar proportion of patients with BMI ≤29 kg/m2 and BMI >29 kg/m2 presented with only PCOS (31.3 versus 32.6%, respectively), with coexisting male factor infertility (64.2 versus 62.8%, respectively) or with tubal factor infertility (4.5 versus 4.7%, respectively). Patient characteristics and stimulation data in the two groups of PCOS patients compared appear in Table 1. In the group of patients with BMI ≤29 kg/m2, a significantly shorter
Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
P = 0.04) and a higher occurrence of OHSS (16.3 versus 3.0%, P = 0.03) was observed in the group of patients with BMI >29 kg/m2 as compared with the group of patients with BMI ≤29 kg/m2, respectively. The median duration of hospitalization due to OHSS in the group of patients with BMI >29 kg/m2 was 3.5 days (interquartile range 2 days). In addition, the group of patients with BMI ≤29 kg/m2 showed a tendency towards a higher ongoing implantation rate and a lower miscarriage rate in comparison to the group of patients with BMI >29 kg/m2.
interval from initiation of rFSH stimulation to GnRH antagonist administration was present. Moreover, these patients were 1.7 ± 0.7 years older than those with BMI >29 kg/m2 and had a lower number of follicles of ≥15 mm on the day of HCG administration as compared with the group of patients with BMI >29 kg/m2. The outcome of patients with PCOS treated by GnRH antagonists and rFSH is shown in Table 2. A significantly lower ongoing pregnancy rate per oocyte retrieval (25.6 versus 46.7%,
Table 1. Comparison of PCOS patients treated with rFSH and GnRH antagonists for IVF/ICSI. Characteristics
Female age (years) Previous IVF/ICSI trials FSH at initiation of stimulation (IU/l) Duration of stimulation before antagonist (days) Duration of rFSH stimulation (days) Total units of rFSH (IU) Oestradiol at HCG day (pg/ml) Progesterone at HCG day (ng/ml) LH at HCG day (IU/l) Number of follicles of ≥15mm at HCG daya Number of cumulus–oocyte –complexes Number of 2PN oocytes Fertilization rate (%) Number of embryos transferred Mean quality score of transferred embryos
BMI ≤29 kg/m2
BMI >29 kg/m2
Starting dose 100 IU
Starting dose 200 IU
31.3 ± 0.4 0.9 ± 0.1 6.4 ± 0.3
29.6 ± 0.6 0.9 ± 0.2 6.4 ± 0.5
0.01 0.93 0.42
5.6 ± 0.1
6.3 ± 0.2
0.01
11.0 ± 0.3
10.9 ± 0.4
0.66
1451 ± 71 2073 ± 166 1.1 ± 0.1
2481 ± 153 2116 ± 193 1.2 ± 0.1
0.001 0.66 0.20
1.3 ± 0.2 8.6 ± 0.5
1.5 ± 0.3 10.7 ± 0.6
0.51 0.01
13.5 ± 1.0
15.2 ± 1.4
0.14
7.0 ± 0.6 74.4 ± 2.9 2.0 ± 0.1
10.1 ± 1.0 78.6 ± 2.3 2.1 ± 0.1
0.01 0.54 0.70
1.9 ± 0.1
1.8 ± 0.1
0.54
P-value
PN = pronuclear. aNo difference was observed between the two groups in the number of follicles ≥11mm and ≥17mm on the day of HCG administration.
Table 2. Outcome of PCOS patients treated with GnRH antagonists and rFSH for IVF/ICSI. BMI ≤29 kg/m2
BMI >29 kg/m2
Starting dose 100 IU
Starting dose 200 IU
Ongoing pregnancy rate per oocyte retrieval Pregnancies (n) Percentage
28/60 (47.3)
11/43 (25.7)
0.04
Ongoing implantation rate Percentage
29.3 ± 4.8
19.0 ± 5.5
0.07
Miscarriage rate Pregnancies (n) Percentage
1/29 (3.4)
3/14 (21.4)
0.09
Ovarian hyperstimulation syndrome rate Pregnancies (n) Percentage
2/67 (3.0)
7/43 (16.3)
0.03
Outcome
P-value
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Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Discussion This study shows that in GnRH antagonist cycles, a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH. As far as is known, this is the first study evaluating the outcome of IVF/ICSI in PCOS patients treated with GnRH antagonists and rFSH. The higher starting dose of FSH applied to the group of patients with BMI >29 kg/m2 as compared with the group with BMI ≤29 kg/m 2 , aimed at minimizing the effect of the increased BMI in the duration of follicular phase. Indeed, as shown in Table 1, a similar duration of stimulation was observed between the two groups compared (10.9 ± 0.4 days versus 11.0 ± 0.3 days, respectively). Moreover, similar concentrations of oestradiol on the day of HCG administration and no difference in the number of cumulus–oocyte–complexes retrieved were observed in both BMI groups (Table 1). Under the current study design, the difference in ongoing pregnancy rate between the two groups compared might be attributed to the effect of BMI and/or the effect of the starting dose of rFSH used. However, a relationship between an increased starting dose of FSH and an adverse pregnancy outcome has not been established in antagonist cycles. Indirect data on this relationship are available at present only for non-PCOS patients. During phase-three comparative studies between agonists and antagonists, the highest pregnancy rate was observed in the North American trial (Fluker et al., 2001) in which stimulation started with the highest gonadotrophin dose as compared with the other four trials (Albano et al., 2000; Borm and Mannaerts, 2000; The Middle East Orgalutran Study Group, 2001; Olivennes et al., 2000). Moreover such a relationship has not been shown for GnRH agonist cycles (Wikland et al., 2001). It is thus likely that the significantly lower ongoing pregnancy rate observed in the group of patients with high BMI might be attributed mainly to the increased obesity itself and, to a lesser degree, to the different starting dose of gonadotrophin. Obesity can affect gonadotrophin pharmacokinetics (Fridstrom et al., 1997; Mannaerts et al., 1993), leptin concentrations and metabolism of sex steroids (Azziz, 1989) and has been associated with an adverse pregnancy outcome (Norman and Clark, 1998; Franks, 2003). In addition, it is related to increased insulin resistance/hyperinsulinaemia. Insulin enhances androgen production by theca cells and the elevated insulin in PCOS patients is believed to be the cornerstone of the resulting ovarian dysfunction (Utiger, 1996). Although both lean and obese women with PCOS show evidence of decreased insulin sensitivity, insulin resistance accompanied by compensatory hyperinsulinaemia is most marked when there is an interaction between obesity and the syndrome (Dunaif et al., 1987, 1989).
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Whatever the mechanism involved, the significantly lower ongoing pregnancy rate in the group of patients with BMI >29 kg/m2 does not appear to be related to the number or the
quality of the embryos transferred in PCOS patients which were similar between the two groups compared. Furthermore, PCOS patients with BMI >29 kg/m2 had significantly more 2PN oocytes and were significantly younger than those with BMI ≤29 kg/m2, which makes an embryonic factor as a cause for a worse reproductive outcome in patients with BMI >29 kg/m2 less likely. However, a longer interval from initiation of rFSH stimulation until initiation of GnRH antagonist (by a follicle of ≥15 mm in ultrasound scan) was required in the patients with BMI >29 kg/m2, despite a higher starting dose of rFSH. Sixty-eight per cent of the patients with BMI ≤29 kg/m2 started GnRH antagonist on day 6 of stimulation compared with 40% of the patients in the group with BMI >29kg/m2 (P = 0.009). A delayed antagonist initiation when there is no follicle of ≥15 mm after 5 days of rFSH stimulation, has been shown to result in a lower implantation rate as compared with fixed initiation after 5 days in non-PCOS patients (Kolibianakis et al., 2003). The fact that in the group with BMI >29 kg/m2 significantly more patients started GnRH antagonist after more than 5 days of rFSH stimulation might explain the difference observed in ongoing pregnancy rates between the two BMI groups. It may be worth evaluating the effect of earlier antagonist administration in this group of PCOS patients with BMI >29 kg/m2. Moreover, the use of metformin in PCOS patients undergoing IVF should also be considered (Stadtmauer, 2002). Considering the difference observed in OHSS incidence between the two groups compared, it could be supported that this is a consequence of the higher dose of FSH used in the group of patients with BMI >29 kg/m2 which has led to significantly more follicles ≥15 mm being present on the day of HCG administration and thus to an increased risk of developing OHSS. Although this might be true, no difference was observed in the total number of follicles ≥11 mm or the number of follicles ≥17 mm on the day of HCG. In addition, similar oestradiol concentrations were also present between the two groups compared on the same day. Moreover, there appears to be no linear positive relationship between OHSS occurrence and gonadotrophin quantity used for stimulation (Delvigne and Rozenberg, 2002). On the contrary, patients suffering from OHSS often receive much less gonadotrophin than others (Navot et al., 1988; Smitz et al., 1990; Delvigne et al., 1993; Enskog et al., 1999). It is possible, however, that the significantly lower age of patients with BMI >29 kg/m2 might also be involved in the difference in OHSS occurrence (Golan et al., 1988; Navot et al., 1988). Nevertheless patients admitted in both groups due to OHSS did not require prolonged hospitalization. At least in patients with BMI >29 kg/m2 it is probably worth evaluating the use of GnRH agonists as a signal for triggering final oocyte maturation (Felberbaum and Diedrich, 2003; Howles, 2002; Olivennes, 2002; Olivennes et al., 2002). In conclusion, a worse reproductive outcome is expected in PCOS patients with BMI >29 kg/m2 in whom stimulation is initiated with 200 IU of rFSH as compared with PCOS patients with BMI ≤29 kg/m2 in whom stimulation is initiated with 100 IU of rFSH, when GnRH antagonists are used for inhibition of premature LH surge.
Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
Acknowledgements The authors would like to thank Mrs Julie Deconick for correcting the manuscript. This work is supported by grants from the Fund for Scientific Research, Flanders, Belgium.
References Adams J, Franks S, Polson DW et al. 1985 Multifollicular ovaries: clinical and endocrine features and response to pulsatile gonadotropin releasing hormone. Lancet 2, 1375–1379. Albano C, Felberbaum RE, Smitz J et al. 2000 Ovarian stimulation with HMG: results of a prospective randomized phase III European study comparing the luteinizing hormone-releasing hormone (LHRH)-antagonist cetrorelix and the LHRH-agonist buserelin. European Cetrorelix Study Group. Human Reproduction 15, 526–531. Azziz R 1989 Reproductive endocrinologic alterations in female asymptomatic obesity. Fertility and Sterility 52, 703–725. Balen AH, Tan SL, MacDougall J et al. 1993 Miscarriage rates following in-vitro fertilization are increased in women with polycystic ovaries and reduced by pituitary desensitization with buserelin. Human Reproduction 8, 959–964. Borm G, Mannaerts B 2000 Treatment with the gonadotrophinreleasing hormone antagonist ganirelix in women undergoing ovarian stimulation with recombinant follicle stimulating hormone is effective, safe and convenient: results of a controlled, randomized, multicentre trial. The European Orgalutran Study Group. Human Reproduction 15, 1490–1498. Dale O, Tanbo T, Lunde O et al. 1993 Ovulation induction with lowdose follicle-stimulating hormone in women with the polycystic ovary syndrome. Acta Obstetrica Gynecologica Scandinavica 72, 43–46. Delvigne A, Rozenberg S 2002 Epidemiology and prevention of ovarian hyperstimulation syndrome (OHSS): a review. Human Reproduction Update 8, 559–577. Delvigne A, Demoulin A, Smitz J et al. 1993 The ovarian hyperstimulation syndrome in in-vitro fertilization: a Belgian multicentric study. I. Clinical and biological features. Human Reproduction 8, 1353–1360. Devroey P, Tjandraprawira K, Mannaerts B et al. 1995 A randomized, assessor-blind, group-comparative efficacy study to compare the effects of Normegon and Metrodin in infertile female patients undergoing in-vitro fertilization. Human Reproduction 10, 332–337. Dunaif A, Graf M, Mandeli J et al. 1987 Characterization of groups of hyperandrogenic women with acanthosis nigricans, impaired glucose tolerance, and/or hyperinsulinemia. Journal of Clinical Endocrinology and Metabolism 65, 499–507. Dunaif A, Segal KR, Futterweit W et al. 1989 Profound peripheral insulin resistance, independent of obesity, in polycystic ovary syndrome. Diabetes 38, 1165–1174. Enskog A, Henriksson M, Unander M et al. 1999 Prospective study of the clinical and laboratory parameters of patients in whom ovarian hyperstimulation syndrome developed during controlled ovarian hyperstimulation for in-vitro fertilization. Fertility and Sterility 71, 808–814. Fedorcsak P, Dale PO, Storeng R et al. 2001 The impact of obesity and insulin resistance on the outcome of IVF or ICSI in women with polycystic ovarian syndrome. Human Reproduction 16, 1086–1091. Felberbaum RE, Diedrich K 2003 Gonadotrophin-releasing hormone antagonists: will they replace the agonists? Reproductive BioMedicine Online 6, 43–53. Fluker M, Grifo J, Leader A et al. 2001 Efficacy and safety of ganirelix acetate versus leuprolide acetate in women undergoing controlled ovarian hyperstimulation. Fertility and Sterility 75, 38–45. Franks S 2003 Gonadotrophin regimens and oocyte quality in women
with polycystic ovaries. Reproductive BioMedicine Online 6, 181–184. Fridstrom M, Sjoblom P, Pousette A, Hillensjo T 1997 Serum FSH levels in women with polycystic ovary syndrome during ovulation induction using down-regulation and urofollitropin. European Journal of Endocrinology 136, 488–492. Gambineri A, Pelusi C, Vicennati V et al. 2002 Obesity and the polycystic ovary syndrome. International Journal of Obesity and Related Metabolic Disorders 26, 883–896. Gardner DK, Schoolcraft WB 1999 In-vitro culture of human blastocysts. In: Jansen R, Mortimer D (eds), Towards Reproductive Certainty: Infertility and Genetics Beyond 1999. Parthenon Press, Carnforth, UK, pp. 377–388. Golan A, Ron-El R, Herman A et al. 1988 Ovarian hyperstimulation syndrome following D-Trp-6 luteinizing hormone-releasing hormone microcapsules and menotropin for in vitro fertilization. Fertility and Sterility 50, 912–916. Homburg R, Levy T, Berkovitz D et al. 1993 Gonadotropin-releasing hormone agonist reduces the miscarriage rate for pregnancies achieved in women with polycystic ovarian syndrome. Fertility and Sterility 59, 527–531. Homburg R, Orvieto R, Bar-Hava I et al. 1996 Serum levels of insulin-like growth factor-1, IGF binding protein-1 and insulin and the response to human menopausal gonadotrophins in women with polycystic ovary syndrome. Human Reproduction 11, 716–719. Howles CM 2002 The place of gonadotrophin-releasing hormone antagonists in reproductive medicine. Reproductive BioMedicine Online 4, 64–71. Kolibianakis EM, Albano C, Kahn J et al. 2003 Exposure to high levels of luteinizing hormone and estradiol in the early follicular phase of gonadotropin-releasing hormone antagonist cycles is associated with a reduced chance of pregnancy. Fertility and Sterility 79, 873–880. Mannaerts B, Shoham Z, Schoot D et al. 1993 Single-dose pharmacokinetics and pharmacodynamics of recombinant human follicle-stimulating hormone (Org 32489®) in gonadotropindeficient volunteers. Fertility and Sterility 59, 108–114. Navot D, Relou A, Birkenfeld A et al. 1988 Risk factors and prognostic variables in the ovarian hyperstimulation syndrome. American Journal of Obstetrics and Gynecology 159, 205–210. Norman RJ, Clark AM 1998 Obesity and reproductive disorders: a review. Reproduction, Fertility and Development 10, 55–63. Olivennes F 2002 GnRH antagonists: do they open new pathways to safer treatment in assisted reproductive techniques? Reproductive BioMedicine Online 5, 20–25. Olivennes F, Belaisch-Allart J, Emperaire JC et al. 2000 Prospective, randomized, controlled study of in-vitro fertilization- embryo transfer with a single dose of a luteinizing hormone-releasing hormone (LH-RH) antagonist (cetrorelix) or a depot formula of an LH-RH agonist (triptorelin). Fertility and Sterility 73, 314–320. Olivennes F, Cunha-Filho JS, Fanchin R et al. 2002 The use of GnRH antagonists in ovarian stimulation. Human Reproduction Update 8, 279–290. Schmidt, KL, Ziebe S, Popovic B et al. 2001 Progesterone supplementation during early gestation after in vitro fertilization has no effect on the delivery rate. Fertility and Sterility 75, 337–341. Smitz J, Camus M, Devroey P et al. 1990 Incidence of severe ovarian hyperstimulation syndrome after GnRH agonist/HMG superovulation for in-vitro fertilization. Human Reproduction 5, 933–937. Stadtmauer LA, Toma SK, Riehl RM et al. 2002 Impact of metformin therapy on ovarian stimulation and outcome in ‘coasted’ patients with polycystic ovary syndrome undergoing invitro fertilization. Reproductive BioMedicine Online 5, 112–116. Staessen C, Camus M, Bollen N et al. 1992 The relationship between embryo quality and the occurrence of multiple pregnancies. Fertility and Sterility 57, 626–630.
317
Articles - GnRH antagonists and rFSH for IVF/ICSI in PCOS patients - E Kolibianakis et al.
The Middle East Orgalutran Study Group 2001 Comparable clinical outcome using the GnRH antagonist ganirelix or a long protocol of the GnRH agonist triptorelin for the prevention of premature LH surges in women undergoing ovarian stimulation. Human Reproduction 16, 644–651. Utiger RD 1996 Insulin and the polycystic ovary syndrome. New England Journal of Medicine 335, 657–658. Van Steirteghem AC, Nagy Z, Joris H et al. 1993 High fertilization
318
and implantation rates after intracytoplasmic sperm injection. Human Reproduction 8, 1061–1066. Wikland, M, Bergh C, Borg K et al. 2001 A prospective, randomized comparison of two starting doses of recombinant FSH in combination with cetrorelix in women undergoing ovarian stimulation for IVF/ICSI. Human Reproduction 6, 1676–1681.
Received 28 May 2003; refereed 26 June 2003; accepted 14 July 2003.