Assisted reproduction in the treatment of polycystic ovarian syndrome

RBMOnline - Vol 8. No 4. 2004 419-430 Reproductive BioMedicine Online; www.rbmonline.com/Article/1265 on web 16 February 2004

Outlook Assisted reproduction in the treatment of polycystic ovarian syndrome After his residency training in Obstetrics and Gynecology in the University of Hacettepe in Ankara, Dr Urman completed a 3-year fellowship programme in Reproductive Endocrinology and Infertility in Vancouver, Canada. He returned to Hacettepe University in 1991 and participated in the foundation of one of the first IVF clinics in Turkey. He worked as an Associate Professor until 1996 in the same institution. Dr Urman resigned from the university in 1996 and founded the Assisted Reproduction Unit of the American Hospital of Istanbul, one of the biggest IVF centres in the country. His major areas of interest are clinical assisted reproduction, laparoscopic and hysteroscopic surgery. He has published extensively in these fields, having over 70 articles published in renowned international journals. Dr Bulent Urman Bulent Urman1,3, Bulent Tiras2, Kayhan Yakin1 Reproduction Unit, American Hospital of Istanbul; 2Department of Obstetrics and Gynecology, Gazi University, Ankara 3Correspondence: Vehbi Koc Vakfi Amerikan Hastanesi, Guzelbahce Sok No. 20, Nisantasi, Istanbul, Turkey. e-mail: [email protected]

1Assisted

Abstract Treatment of patients with polycystic ovary syndrome (PCOS) with assisted reproductive techniques is a great challenge for the infertility specialist. Patients with PCOS demonstrate many problems, such as excessive body weight and hyperinsulinaemia, that render management more complex. Prior to treatment with IVF, the PCOS patient should be thoroughly evaluated for disclosure of endometrial neoplasia, hyperinsulinaemia, and other general health related problems. Ovarian stimulation for IVF carries the risks of overstimulation and severe hyperstimulation, which should be avoidable in most cases with preventive measures. The outcome in terms of pregnancy and implantation rates is similar for patients with PCOS when compared with patients undergoing IVF for other indications. There are some questions regarding oocyte and embryo quality in women with PCOS. This manifests itself in lower fertilization rate and decreased embryo quality in some studies. However, increased numbers of oocytes available for insemination or ICSI compensate for decreased fertilization rates and embryo quality. More recent studies suggest higher cumulative conception rates in women with PCOS when compared with controls. In-vitro maturation (IVM) of oocytes retrieved from non-stimulated or minimally stimulated cycles represents a viable option that should be considered seriously when assisted conception is attempted. Results of IVM, however, should be improved further and generalized before the technique can be advocated as the initial treatment approach in these patients. Keywords: IVF, ovarian hyperstimulation syndrome, polycystic ovarian syndrome

Introduction Polycystic ovarian syndrome (PCOS) is the most common endocrinopathy among reproductive age women (Carmina and Lobo, 1999). In the 1990s the diagnosis of PCOS was entirely clinical, and required the presence of menstrual irregularity and hyperandrogenism after exclusion of other causes (Zawadski and Dunaif, 1992). In 2001, a consensus meeting was held in the National Institutes of Health, and more importance was given to the presence of polycystic ovarian morphology (Chang, 2002). Epidemiological studies suggest that approximately 4–7% of reproductive age women have PCOS and 16–25% of an otherwise normal population have isolated polycystic ovarian morphology (PCO) on ultrasound (Polson et al., 1988; AbdelGadir et al., 1992; Carmina and Lobo, 1999).

Infertile women with PCOS are usually successfully treated with first line ovulation inducing agents such as clomiphene citrate and more recently with insulin-sensitizing medications. Those who do not conceive are candidates for gonadotrophin treatment or laparoscopic ovarian drilling. It is for the unfortunate few that treatment with assisted reproductive techniques is mandated. In couples referred for IVF for other infertility reasons (i.e. male factor), PCOS may be incidentally present in the female. Furthermore, a certain proportion of women undergoing IVF treatment have PCO. Regardless of the presence of PCOS or PCO, ovarian stimulation in these women is fraught with complications. Under- and overstimulation and ovarian hyperstimulation syndrome (OHSS) are relatively common, as

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Outlook - Assisted reproduction to treat PCOS - B Urman et al.

is early miscarriage of resulting pregnancies. There has been a long and heated debate over the outcome of assisted reproduction in women with PCOS. High oestradiol concentrations and multifollicular development, so commonly associated with ovarian stimulation in these patients, have been regarded as detrimental factors affecting implantation and pregnancy rates.

Preprocedural considerations: endometrial neoplasia, weight loss, treatment of insulin resistance, and ovarian drilling Endometrial neoplasia Chronic anovulation associated with PCOS may lead to endometrial hyperplasia and sometimes to frank endometrial cancer (Meier and Schenker, 1996). This is due to prolonged unopposed oestrogen effects on the endometrium. The presence of a thick endometrium despite spontaneous or induced menstrual bleeding should provoke suspicion and appropriate diagnostic tests should be employed without delay. Endometrial biopsy or, better, a full curettage should be performed. If present, endometrial hyperplasia can be treated with progestagens for 3 months. Resolution of the disease should be confirmed with a follow-up endometrial biopsy. Atypical endometrial hyperplasia and very early stage endometrial cancer have also been treated successfully with progestagens (Lindahl and Willen, 1985; Farhi et al., 1986). The presence of early stage endometrial cancer in these infertile patients presents a great treatment challenge. In stage 1a, grade 1 disease, progestagens can be administered following full curettage. Lack of myometrial invasion should be confirmed with high-resolution transvaginal ultrasonography and MRI. Medroxyprogesterone acetate 30 mg twice daily should be given for 3 months. The patient should then undergo IVF without further delay. In a retrospective study of young patients with endometrial cancer, 60% were successfully treated with progestagen therapy allowing for interval pregnancies (Farhi et al., 1986).

Weight loss Success of assisted reproduction has been shown to decrease with increasing body mass index (Wang et al., 2000). Pregnancy rates are decreased by approximately 30% in women with a BMI >35 compared with women of ideal body weight. Obesity is associated with relative gonadotrophin resistance and increased gonadotrophin consumption (Fedorcsak et al., 2001). Transvaginal oocyte recovery may be more difficult in obese women due to decreased tissue resolution in these individuals. Weight loss should decrease gonadotrophin requirements and difficulties associated with oocyte retrieval. Insulin resistance may also be ameliorated with weight loss (Pasquali et al., 1989; Huber-Buchholz et al., 1999). Weight loss has recently been shown to improve the outcome of all forms of infertility treatments, including IVF (Clark et al., 1998). The above notwithstanding, no randomized study has explored the impact of weight loss on the outcome of IVF in patients with PCOS.

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Increased body weight in pregnancy is associated with certain complications that may be ameliorated with preconception weight loss. The risk of spontaneous abortion is increased in PCOS patients who conceived with IVF (Wang et al., 2001). Higher risk was associated with obesity. There is a higher incidence of gestational diabetes and pregnancy induced hypertension in pregnant women with PCOS (Urman et al., 1997). Furthermore, obesity may lead to increased incidence of fetal malpresentations and dystocia, post-partum haemorrhage and thromboembolism. Perinatal mortality in infants born to obese mothers also appears to be increased.

Insulin resistance Insulin resistance is now accepted as one of the integral components of PCOS (Nestler et al., 2002). Although more common in the obese PCOS patient, insulin resistance may also be present in those who are not obese (Chang et al., 1983; Dunaif et al., 1987, 1989, 1992). Insulin resistance is associated with hyperandrogenic symptoms and resistance to ovulation-inducing agents. Metformin in a dose of 1500–2000 mg has been shown to improve insulin concentrations, insulin sensitivity, and serum androgen concentrations accompanied by a decrease in serum LH and SHBG (Nestler et al., 1998; Homburg and Insler, 2002). Most possibly through changes in the endocrine milieu and paracrine signalling mechanisms metformin enhances spontaneous and clomiphene induced ovulation (Homburg and Insler, 2002; Lord et al., 2003). Furthermore, the use of insulin-sensitizing drugs such as metformin has been shown to reduce fasting insulin concentrations, blood pressure and LDL cholesterol concentrations, which may confer life-long health benefits for the woman with PCOS. In women undergoing ovulation induction with gonadotrophins, the use of metformin was associated with fewer large follicles, decreased oestradiol concentrations and fewer cycles cancelled due to overstimulation and risk of OHSS (De Leo et al., 1999). Initial studies with low dose stepup gonadotrophin treatment suggested that women with insulin resistance had a much greater tendency to develop multiple follicles in response to gonadotrophins that was associated with a higher cycle cancellation rate compared with non-insulin-resistant counterparts (Dale et al., 1998). In-vitro effects of insulin on progesterone and lactate release by granulosa–lutein cells were assessed and found to be impaired in PCOS women undergoing ovarian stimulation and oocyte collection for IVF (Fedorcsak et al., 2000). Fedorcsak et al. studied the impact of insulin resistance on the outcome of IVF/intracytoplasmic sperm injection (ICSI) cycles in women with PCOS. Insulin-resistant women had lower oestradiol concentrations during stimulation and required higher doses of gonadotrophins. However, these differences disappeared after controlling for body weight (Fedorcsak et al., 2001). In a later study, the authors examined the effect of metformin in insulin-resistant women undergoing IVF/ICSI (Fedorcsak et al., 2003). Co-administration of metformin increased the number of oocytes collected, but did not alter gonadotrophin requirements. Stadtmauer et al. assessed the effect of metformin co-treatment in 46 women with PCOS who were undergoing ovarian stimulation for IVF (Stadtmauer et al., 2001). Metformin decreased the total number of follicles

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

without changing the number of follicles >14 mm. This finding is especially important, as the number of small and intermediate follicles appears to be related to OHSS. In this study, the mean number of oocytes retrieved and the embryos cleaved were increased with metformin treatment. Furthermore, fertilization and clinical pregnancy rates were increased. Although the retrospective nature of the study decreases the validity of the results the increase in clinical pregnancy rate from 30 to 70% was especially impressive. The same group later studied the effect of metformin in coasted patients undergoing ICSI (Stadtmauer et al., 2002). The same data set as the previous study was used. Maximum oestradiol concentrations and the duration of coasting were decreased in the metformin group. Moreover, clinical pregnancy rates were significantly higher in the metformin group. Institution of metformin prior to treatment and continuation during early pregnancy of insulin-sensitizing agents was shown to decrease the early loss of IVF pregnancies. Glueck reported that metformin decreased plasminogen activator–inhibitor function, resulting in a decline in the risk of early trimester abortion in women with PCO (Glueck et al., 2001). However, more data need to be accumulated before routine use of insulin-sensitizing agents prior to and during IVF/ICSI treatment. Moreover, safety of these drugs during early pregnancy should be documented.

Laparoscopic ovarian drilling Laparoscopic ovarian drilling has been advocated as an adjuvant treatment to assisted reproduction in women with PCOS. The reasoning behind this is as follows: women with PCOS undergoing ovarian stimulation for IVF are at increased risk of developing overstimulation that may mandate treatment cancellation. In women who proceed to IVF, there is a considerably higher risk of OHSS which when severe may require hospitalization and prolonged treatment. The later may also be life threatening. Several measures have been advocated, most being instituted prior to injection of human chorionic gonadotrophin (HCG), to prevent OHSS. However, none has been shown to be unequivocally effective. Laparoscopic ovarian drilling is associated with reduction of androgens and LH in the PCOS patient (Donesky and Adashi, 1995). Elevated LH concentrations have been held responsible for poor oocyte and embryo quality and subsequently miscarriage (Balen, 1993; Wang et al., 2001). Women with PCOS who have elevated serum LH concentrations have abortion rates of 32–40% following gonadotrophin treatment (Wang and Gemzell, 1980; Hamilton-Fairley et al., 1991). In IVF cycles, oocytes from women with PCOS show lower fertilization rates. Furthermore, implantation rates are lower compared with women with normal LH concentrations (Stanger and Yovich, 1985). Laparoscopic ovarian drilling appears to modify the intraovarian environment through mechanisms that have not been precisely elucidated. Its use, therefore, prior to IVF in women with PCOS may prove to be beneficial. The effect of laparoscopic ovarian drilling on subsequent IVF performance was evaluated prospectively by Colacurci et al. (1997). In patients who underwent laparoscopic ovarian drilling, lower peak oestradiol concentrations and higher pregnancy rates were documented when compared with PCOS

patients who did not undergo the surgical procedure. Rimington et al. (1997), prior to treatment with IVF, randomized 50 women with polycystic ovaries to long-term pituitary desensitization versus laparoscopic ovarian electrocautery. A higher percentage of women in the long-term desensitization group had to be cancelled due to impending OHSS as determined by ultrasound and endocrine findings. Pregnancy and abortion rates were similar between groups. The authors proposed pre-IVF ovarian electrocautery, especially in women who had previously had a cancelled cycle due to OHSS. Tozer et al., in a retrospective study, reached similar conclusions. Although in women who had previously undergone laparoscopic ovarian diathermy, pregnancy rates were higher and miscarriage rates were lower, these did not reach statistical significance (Tozer et al., 2001). Likewise, the rate of OHSS was similar between groups. The benefits expected from laparoscopic ovarian drilling should be weighed against the potential complications associated with laparoscopy. Furthermore, laparoscopic ovarian drilling has been associated with adhesion formation and a possible reduction in ovarian reserve due to destruction of the primordial follicle rich ovarian cortex. There appears to be no improvement in pregnancy rates; however, there is a decrease in OHSS when laparoscopic ovarian drilling is used prior to ovarian stimulation for IVF. Laparoscopic ovarian drilling should be compared with careful ovarian stimulation coupled with coasting and other measures to prevent OHSS. Suppression with oral contraceptives prior to gonadotrophin hormone-releasing hormone analogue (GnRHa) treatment together with low dose gonadotrophin stimulation and adjustment of the dose of HCG should avoid the occurrence of life threatening severe OHSS (Damario et al., 1997).

Ovarian stimulation in the PCOS/PCO patient Ovulation induction for anovulation There are sufficient data in the literature derived from ovulation induction cycles using gonadotrophins in women with clomiphene citrate-resistant PCOS. Information gained from these data suggests that for induction of ovulation in the PCOS patient: (i) Human menopausal gonadotrophin (HMG), urinary-derived FSH, and recombinant FSH (rec-FSH) appear to be equally effective for achieving pregnancy (Nugent et al., 2000; van Wely et al., 2003a). There are contradictory data regarding secondary efficacy end-points such as total gonadotrophin dose and duration of stimulation. While Yarali et al. (1999) found no difference in the duration of stimulation and total gonadotrophin dose required to stimulate anovulatory patients with PCOS, Hugues et al. (2001) showed that when rec-FSH was compared with urinary FSH a lower gonadotrophin dose was required to reach the threshold and complete the cycle. (ii) The incidence of complications, namely multifollicular development, OHSS and multiple pregnancy associated with different gonadotrophin preparations, is similar (Nugent et al., 2000; van Wely et al., 2003b). (iii) The use of GnRHa is associated with exacerbation of multiple follicle development, OHSS and multiple pregnancies (Homburg et al., 1990; Van der Meer et al., 1998). There are data to suggest that co-administration of GnRHa decreases miscarriage rates (Homburg et al., 1993b); however,

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this is not universally accepted (Hughes et al., 2000). (iv) Low-dose step-up gonadotrophin regimens are preferred over conventional step-up and step-down regimens (White et al., 1996; Homburg and Howles, 1999).

Response of polycystic ovary to stimulation The polycystic ovary is unique in terms of its response to stimulation. Follicular response tends to be initially slow, but explosive at later stages of stimulation. At times it may be extremely difficult to find the gonadotrophin threshold. Recruitable pool of follicles in the polycystic ovary is increased. Furthermore, there is stromal hyperplasia contributing larger than normal amounts of androgens to the follicular microenvironment. Granulosa cell aromatase activity is normally decreased in the polycystic ovary; however, it is readily stimulated by exogenous FSH. Higher normal androgen concentrations act in a paracrine manner to increase local oestrogen concentrations, which stimulate FSH receptors. When FSH is administered in this milieu, ovarian response is with multiple follicular development and often very high oestradiol concentrations. This makes the PCOS patient more prone to OHSS. Vascular endothelial growth factor (VEGF) expression is increased in women with polycystic ovaries. The importance of this is 2-fold. One is that VEGF increases vascular permeability, which is a key factor in the pathogenesis of OHSS. Second, widespread and increased expression of VEGF may prevent the divergence of blood flow away from the dominant follicle, a mechanism that is operational in a unifollicular response. Loss of these intraovarian paracrine regulatory mechanisms results in the multifollicular response that is so typical in these patients. Numerous studies have been published to date that lend credence to VEGF as the most important mediator of OHSS (McClure et al., 1994; Neulen et al., 1995; Krasnow et al., 1996; Abramov et al., 1997). Agrawal et al. (1998) showed that in women destined to develop OHSS serum, VEGF concentrations are higher throughout ovarian stimulation. Furthermore, in women who developed OHSS, there was a significant rise in the VEGF concentrations between the administration of HCG and oocyte retrieval (Agrawal et al., 1998). Rises in VEGF concentrations were related to the severity of OHSS (Agrawal et al., 1999). Messenger RNA of VEGF is increased within the hyperthecotic stroma of women with PCOS (Kamat et al., 1995). This increased expression of VEGF is most probably responsible for the increased stromal vascularity of the polycystic ovary. VEGF mediates the neovascularization of the corpus luteum. Women with PCO recruit excessive number of follicles and produce multiple corpora lutea following administration of HCG. These corpora lutea over-express VEGF, which, if it escapes from the ovary, may be responsible for the fluid shift from the vascular bed to the extravascular space.

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Increased body mass index (BMI) and insulin resistance render the management of the PCOS patient even more difficult. Increased BMI increases gonadotrophin requirements. This is, however, at times unpredictable and may lead to an explosive ovarian response when the patient is stimulated with high doses of gonadotrophins. It is always safer to increase the dose

gradually in patients with PCOS in a low dose step-up manner. When the ovarian response has been previously documented, the threshold dose can be initiated from the start.

Ovarian stimulation protocols for PCO/PCOS It should be noted that women with the full-blown syndrome and women with morphologically polycystic ovaries when controlled for body mass index respond similarly to ovarian stimulation. A pretreatment transvaginal ultrasound examination generally accurately predicts the response of the ovary to stimulation (Tomas et al., 1997). Patient age, ovarian volume, and antral follicle count should be taken into account. Antral follicle count appears to be more predictive than others (Bancsi et al., 2002). When the sum of antral follicles in both ovaries was more than 15, these patients demonstrate an exaggerated response to gonadotrophin stimulation. Engman et al. (1999) studied the outcome of IVF in women who had PCO but not the full-blown syndrome and compared them with women with normal ovaries. Women with PCO produced more follicles, oocytes, and embryos. Fertilization, cleavage and spontaneous abortion rates were similar in the two groups. However, when adjusted for age the cumulative conception rate after three cycles of IVF was higher in women with PCO compared with women with normal ovaries. It appears that ovaries with polycystic morphology confer a benefit regarding the outcome of IVF treatment. This is due to the increased number of retrieved oocytes that increases the cohort of selectable and freezable embryos. There has been a long-standing debate regarding the gonadotrophin of choice for ovarian stimulation in women with PCOS. Elevated LH concentrations commonly associated with the syndrome have been blamed for increased incidence of OHSS and spontaneous abortions. Due to the above concerns, gonadotrophin preparations devoid of LH were advocated. Although there are no comparative data regarding the outcome of IVF in PCOS patients stimulated with different gonadotrophin preparations, data from ovulation induction cycles suggest that there are no outcome differences in the gonadotrophin preparations studied (Nugent et al., 2000; van Wely et al., 2003b). Data from IVF cycles irrespective of the indication for IVF are not in concordance. Two meta-analyses studying similar data reached different conclusions. Recombinant FSH (rec-FSH) was found to yield higher pregnancy rates and the total gonadotrophin dose required was lower (Daya, 2002). In this meta-analysis, Daya concluded that for every 19 patients treated one additional patient would conceive when treated with rec-FSH. Spontaneous abortion, multiple pregnancy, and OHSS rates were similar for both gonadotrophins. However, Al-Inany et al. (2002) found no evidence of increased clinical pregnancy rates when rec-FSH was compared with urinary FSH. Another recent meta-analysis concluded that urinary HMG was associated with higher clinical pregnancy rates in cycles down regulated by GnRHa (van Wely et al., 2003b). Goldfarb and Desai (2003), however, in a non-randomized study found that rec-FSH was more efficacious than HMG and furthermore resulted in a higher implantation rate. Unfortunately neither trial undertook a subgroup analysis to show whether there was any difference when patients were

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

stratified according to the indication for IVF. Therefore in patients with PCOS undergoing IVF, firm conclusions cannot be reached regarding the superiority of one gonadotrophin preparation over the other.

Although fewer oocytes were retrieved, higher implantation and clinical pregnancy rates were obtained. None of the 61 patients treated with a low dose rec-FSH protocol developed OHSS.

As women with PCOS have elevated LH concentrations, gonadotrophin preparations devoid of LH may in theory be more physiological. It has been shown that in women with polycystic ovaries suppression of LH concentrations with GnRHa prior to stimulation may reduce the incidence of spontaneous abortions (Balen et al., 1993). While women stimulated with clomiphene citrate had the highest abortion rates, a significant decrease was observed especially when GnRHa in a long protocol were combined with HMG. Spontaneous abortion rates were not affected by treatment with HMG versus urinary FSH in patients with normal or polycystic ovaries. Similar conclusions were reached by Homburg et al. who also showed decreased abortion rates and increased cumulative conception rates when GnRHa were used in a long protocol prior to HMG (Homburg et al., 1993b). It can be concluded from limited data that rec-FSH or urinary FSH do not confer a significant benefit over HMG for ovarian stimulation following down regulation with GnRHa. Whether prolonging the duration of GnRHa treatment (ultralong protocol) would be further beneficial remains to be shown.

Protocols utilizing GnRH antagonists can also be used for women with PCOS undergoing ovarian stimulation for IVF. There are, however, no peer reviewed data regarding the application of these medications specifically for patients with PCOS. It should not be unrealistic to expect similar outcomes to patients with normal ovaries. Large multicentre studies have been conducted that compared antagonists with agonists. A meta-analysis of these studies showed small but significant decreases in ovarian response and implantation compared with long GnRHa protocols (Al-Inany and Aboulghar, 2002). The minor differences may be due to inexperience, the presence of an early growing follicle at the initiation of gonadotrophins, and excessive suppression of LH in some patients. Oral contraceptive pretreatment and maintaining or increasing the dose of gonadotrophins once the antagonist is initiated should yield better results. The later may, however, render cycle management in the brittle PCOS patient more difficult, as coasting is often necessary in these patients as a measure to prevent overstimulation. GnRH antagonists during coasting have been successfully used in a patient at risk of hyperstimulation during ovulation induction with a low dose step-up protocol (Fatemi et al., 2002). The antagonist prevented the untimely occurrence of an LH surge and prevented OHSS. The patient underwent IVF and achieved an ongoing twin pregnancy.

The recent introduction of GnRH antagonists provides a new and exciting means to ovarian stimulation. Both the duration and cost of treatment appear to be decreased with antagonist use. There is, however, no controlled study that compared antagonists with agonists in women with PCOS undergoing ovarian stimulation for IVF. The dose of gonadotrophin used in the PCO/PCOS patient should be selected very carefully. These patients are particularly prone to ovarian hyperstimulation. Mild hyperstimulation is encountered in almost all patients with PCOS. However, severe forms of the disease should be avoidable in most cases. GnRHa in a long protocol are generally used, as they avoid unwanted LH surges and decrease the incidence of spontaneous abortions in women who conceive (Meldrum, 1989; Hughes et al., 1992). Furthermore, their use is also associated with the convenience of easier cycle manipulation. The above notwithstanding, in a relatively small study HMG combined with either clomiphene citrate or FSH versus HMG/FSH plus GnRHa cycles yielded similar pregnancy rates (Turhan et al., 1993). The value of ultralong GnRHa regimens remains to be shown. Administration of oral contraceptives prior to initiation of GnRHa has been shown to decrease the rate of OHSS and increase the rates of fertilization, embryo implantation and clinical pregnancy (Damario et al., 1997). Whether administration of insulin-sensitizing agents prior to and during ovarian stimulation in women with PCOS improves the treatment outcome is also controversial. The dose of gonadotrophin should initially be as low as possible. It is current practice to start the treatment at a dose of 150 IU/day considering the BMI. Conditions for starting gonadotrophins are the same as in women with normal ovaries. A lower dose protocol with a starting dose of 75 IU of rec-FSH have yielded impressive results in women with PCOS undergoing ovarian stimulation for IVF (Marci et al., 2001).

Overstimulation and hyperstimulation Response of the PCO to stimulation is often unpredictable. Recruitment of a large number of follicles and excessive rise in oestradiol is usually a concern for the clinician managing the cycle. Gonadotrophin dose should be decreased once the stimulation threshold is reached. Coasting should be seriously considered when leading follicles reach or exceed 14 mm in size and serum oestradiol is >3000 pg/ml. Earlier coasting may be associated with cessation of follicle growth and precipitous drop in oestradiol concentrations. Several studies address the efficacy of coasting for prevention of OHSS (Sher et al., 1995; Waldenstrom et al., 1999; Ohata et al., 2000; Grochowski et al., 2001; D’Angelo and Amso, 2002; Delvigne and Rozenberg, 2002; Egbase et al., 2002). In most studies a threshold value of 3000 pg/ml for serum oestradiol was used. Fertilization and pregnancy rates were acceptable when compared with results from large IVF databanks (Delvigne and Rozenberg, 2002). However, prolonged coasting (over 3 days) or more than 20% drop in the oestradiol concentration after HCG have been reported to be associated with poor clinical outcome (Chen et al., 2003; Levinsohn-Tavor et al., 2003). Other measures besides coasting that can be implemented to prevent or decrease the incidence of OHSS in overstimulated patients include cycle cancellation, administration of a reduced dose of HCG, and substitution of recombinant LH for HCG (Damario et al., 1997; European Recombinant LH Study Group, 2001). If the cycle is cancelled, injections of agonist or antagonist should be continued to prevent an endogenous LH surge. Continuation of the antagonist in a woman with

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imminent hyperstimulation led to a rapid decline in serum oestradiol and diminution of ovarian size (de Jong et al., 1998). When HCG is administered, the dose should be adjusted according to the oestradiol concentration. The dose should be reduced to 5000 IU if oestradiol is >3000 and further to 3300 IU when oestradiol is >5000 pg/ml (Damario et al., 1997). Recombinant LH has been shown to be as effective as HCG for induction of final follicular maturation. A single dose of 15,000–30,000 IU of recombinant LH was found to be as effective as 5000 IU HCG in terms of safety and efficacy (European Recombinant LH Study Group, 2001). Due to a shorter half-life rec-LH should decrease the risk of OHSS. Once the ovulatory dose of HCG is administered, the PCOS patient is faced with the real danger of severe OHSS. Particularly when there is an abundance of intermediary follicles in the presence of high oestradiol concentrations, the risk of severe hyperstimulation is high. Several measures have been advocated to prevent the occurrence of severe hyperstimulation following the administration of HCG (Delvigne and Rozenberg, 2003). These include the infusion of high molecular weight solutions such as human serum albumin, hydroxyethylstarch (HES), and late transfer of embryos so that early onset hyperstimulation can be identified, cryopreservation of all embryos, and the administration of renin–angiotensin cascade inhibitors (Konig et al., 1998; Abramov et al., 2001; Delvigne and Rozenberg, 2003). Current policy is to infuse HES solution 500 ml at the time of OPU and 1000 ml at the time of embryo transfer. Compared with human serum albumin, HES yields similar results and is less expensive. It is preferable to delay embryo transfer until day 5 so that the patient can be evaluated better. Three embryos are left in culture and the rest are frozen on day 3. If the patient has no ascites, abdominal pain, or haemoconcentration, one or two blastocysts are transferred. If there are symptoms and signs of impending OHSS, the blastocysts are cryopreserved and the patient is scheduled for a frozen–thawed embryo transfer. In the latter group of patients, administration of renin–angiotensin cascade inhibitors may block the occurrence of severe OHSS. Treatment of OHSS is beyond the scope of this review.

Results of assisted reproduction in women with PCO/PCOS It is generally agreed that the outcome of assisted reproduction in women with polycystic ovaries and in women with PCOS is similar to women with other forms of infertility. Comparative studies, however, are few (Table 1) (Dor et al., 1990; Urman et al., 1992; Homburg et al., 1993a; MacDougall et al., 1993; Kodama et al., 1995; Doldi et al., 1999; Engmann et al., 1999; Ludwig et al., 1999; Mulders et al., 2003). Women with PCO/PCOS produce more follicles and oocytes due to their intrinsic responsiveness to gonadotrophins. In all studies, the number of retrieved oocytes was higher in PCOS patients. Despite lower fertilization rates reported in some studies, pregnancy rates and cumulative pregnancy rates were similar. Lower fertilization rates were compensated with the increased number of oocytes available for insemination of ICSI.

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In patients with PCOS cycle cancellations were more common, most often due to impending OHSS. The availability of more oocytes may, however, confer some benefit regarding the number of selectable and freezable embryos. All studies reported clinical pregnancies per embryo transfer. Comparison of pregnancy and live birth rates per cycle and preferably cumulative pregnancy rates with the inclusion frozen–thawed embryo transfer cycles should yield more realistic results comparing outcome should be compared. The outcome of IVF was analysed in women with PCOS who had failed to conceive with clomiphene citrate and subsequently with exogenous gonadotrophin therapy (Table 2). Data from embryo transfer cycles in the years 1996–2000 were analysed. All patients had received 4–6 cycles of HMG/FSH prior to initiation of treatment with IVF. A total of 271 cycles in 195 PCOS patients were compared with 247 cycles in 197 controls matched for age and duration of infertility who had normal ovarian morphology on baseline ultrasound. All patients were stimulated with a mid-luteal long GnRHa combined with pure/rec-FSH. Of the 271 cycles in PCOS patients, 15 were cancelled due to impending OHSS or due to delayed and discordant follicular growth. Duration of stimulation was significantly longer in the PCOS group. Peak oestradiol concentrations prior to coasting were also higher in women with PCOS. More oocytes were collected in the PCOS group. Clinical pregnancy, implantation and abortion rates were similar between groups. Mild to moderate ovarian hyperstimulation was seen in 16.6% of patients with PCOS. Severe OHSS requiring hospitalization was encountered in 3.9% of the subjects. It can be concluded that women with PCOS/PCO have a favourable outcome when treated with IVF. The risk of OHSS, however, is higher.

Oocyte and embryo quality and implantation in women with PCOS Two features of PCOS may be relevant for oocyte and embryo quality in IVF. Patients with PCOS have tonically elevated LH concentrations. High LH is thought to be detrimental to oocyte maturation and embryo quality, and furthermore may impair implantation and result in increased incidence of spontaneous abortions (Adams et al., 1985; Howles et al., 1986; Homburg et al., 1988; Regan et al., 1990). In PCOS patients, high oestradiol concentrations are usually reached during ovarian stimulation. High oestradiol concentrations have been associated with poor oocyte quality and lower implantation rates (Ashkenazi et al., 1995; Pellicer et al., 1996; Aboulghar et al., 1997; Akagbosu et al., 1998; Valbuena et al., 2001). However, it should be noted that different clinical studies produced discrepant results (Chenette et al., 1990; Sharara and McClamrock, 1999). Oocytes from patients who were hyperstimulated were found to be of inferior quality (Aboulghar et al., 1997; Akagbosu et al., 1998). Abnormal endocrine milieu resulting in elevated LH, elevated androgens, and hyperinsulinaemia may be responsible for altered oocyte quality in these women. Follicles from women with PCOS are more heterogenous than those form normal ovaries and hypersecrete both oestradiol and progesterone (Willis et al., 1998; Franks et al., 2003). These follicles were shown to be prematurely responsive to LH (Willis et al., 1998). Hyperinsulinaemia may contribute to this abnormal

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

Table 1. Results of studies that compared the outcome of IVF in patients with PCOS versus controls. Author

PCO No. cycles

Dor et al. (1990) Urman et al. (1992) Homburg et al. (1993a) McDougall et al. (1993) Kodama et al. (1995) Doldi et al. (1999) Ludwig et al. (1999) Engmann et al. (1999)a Mulders et al. (2003)

26 19 208 76 78 84 51 97 26

M-II Fertilized (%)

Embryo transfer

PR IR (%) (%)

Tubal/other No. M-II cycles

19.3 7.6

55.0

3.7 3.9

9.3

52.8

11.5 7.9 11.7 11.8

61.8 62.7 59.4 50.0

30.7 24.0 23.0 25.4 25.0 22.6 25.0 10.2 66.5b 18.6 55.0 36.0

37 40 143 76 423 84 105 332 26

2.3 2.7 2.3

Fertilized Embryo (%) transfer

5.4 5.6

75.0

6.8

66.1

7.8 6.3 8.5 10.9

73.5 56.4 60.2 62.0

3.6 4.0

2.3 2.2 2.3

PR IR (%) (%) 29.7 25.0 26.0 23.0 34.0 19.0 22.0 11.8 46.9b 11.7 32.0 19.0

aPCO morphology on USG. bCumulative PR.

Table 2. The IVF outcome of PCOS patients who failed to conceive with gonadotrophin treatment compared with controls with normal ovaries matched for age and duration of infertility.

Patients Initiated cycles ET cycles Cancelled cycles (%) Mean age (years) Duration of infertility (years) Duration of stimulation (days) Ampoules Peak oestradiol (pg/ml) Oocytes Mean no. embryos transferred (ET) CPR/ET (%)a Implantation (%) Abortion rate (%) Mild–moderate OHSSb (%) Severe OHSS (%)

Controls

PCOS

P-value

197 247 235 12 (4.8) 31.27 8.48 10.2 40.3 2300.6 11.42 3.2 96/235 (40.8) 150/631 (23.8) 9/81 (11.1) 8/235 (3.3) 2/235 (0.8)

195 271 252 19 (7.0) 31.83 8.35 11.5 41.8 2946.9 13.81 3.3 117/252 (46.4) 164/644 (25.5) 17/91 (18.7) 42/252 (16.6) 10/252 (3.9)

NS NS <0.05 NS <0.001 <0.01 NS NS NS NS <0.01 <0.05

Values are numbers unless otherwise stated. aClinical pregnancy per embryo transfer. bOvarian hyperstimulation syndrome.

follicular response to LH. It is most likely that abnormal endocrine environment is relevant to abnormal oocyte maturation and decreased fecundity. Errors in embryogenesis resulting from abnormal oocyte maturation may explain the higher rate of pregnancy loss following gonadotrophininduced ovulation and IVF and embryo transfer. Another factor that may be considered is intrinsic abnormalities of the oocyte in patients with PCOS. Abnormal expression of growth differentiation factor-9 (GDF-9) was recently shown in oocytes from PCOS patients (Filho et al., 2002). GDF-9 is an important oocyte derived factor that takes part in both early follicular development and cumulus expansion in the preovulatory follicle (Elvin et al., 2000).

Contrary to the laboratory data, clinical experience from assisted reproduction suggests that PCOS patients fare equally well when treated with IVF–ET. Ludwig et al. compared oocytes from PCOS with oocytes from age-matched controls undergoing ICSI for other indications (Ludwig et al., 1999). There was no difference regarding morphological criteria, embryo quality and implantation; however, spontaneous abortion rates in the PCOS group were higher. In in-vitro maturation (IVM) cycles with and without stimulation, oocyte quality as judged by rates of fertilization and embryo cleavage was similar (Barnes et al., 1996; Child et al., 2001). In another study examining the results of IVM, oocyte morphology scores at metaphase II and fertilization and

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cleavage rates were found to be similar in women with and without polycystic ovaries (Mikkelsen and Lindenberg, 2001). Franks, in an unpublished study, suggests that the uptake of pyruvate, which is an important primary fuel source for the oocyte and preimplantation embryo, was similar in oocytes derived from normal or polycystic ovaries. Nuclear maturation of oocytes matured in vitro was also unaffected, whether they were obtained from normal of polycystic ovaries. The above notwithstanding, certain abnormalities in PCOS may affect oocyte and embryo quality. Cano et al. (1997) reported lower fertilization and implantation rates in hyperinsulinaemic PCOS patients. Finally, chromosomal normality of oocytes from PCOS patients was compared with oocytes from patients with normal ovaries (Sengoku et al., 1997). Cytogenetic analysis was performed on 74 oocytes from PCOS and 73 oocytes from control patients. There was no difference between aneuploidy, diploidy, and prematurely condensed sperm chromosome. The incidence of reduced oocyte fertilization in PCOS patients reported in some studies, therefore, cannot be attributed to chromosomal abnormality. Oestrogen is essential for implantation. There appears to be a transition from the non-receptive to the receptive state in response to oestrogen and progesterone. The molecular basis of this receptive state when the endometrium is conducive to blastocyst acceptance and implantation remains poorly understood. Data from oocyte donation cycles suggest that the window of implantation is relatively narrow in the human. Using embryo transfers and the progesterone-delayedimplantation model in mice, Ma et al. (2003) were able to demonstrate that concentrations of oestrogen within a very narrow range determine the duration of window of uterine receptivity. Although oestrogen at different physiological concentrations can initiate implantation, they showed that the window of uterine receptivity remained open for an extended period at lower oestrogen concentrations, but rapidly closed at higher concentrations. The uterine refractoriness that followed the receptive state at high oestrogen concentrations was accompanied by aberrant uterine expression of implantation related genes. High oestrogen concentrations associated with ovarian stimulation particularly in PCOS patients may be detrimental to embryonic implantation at least in part due to the above mechanisms. Furthermore, Valbuena et al. (2001) showed that high oestrogen concentrations were deleterious to embryo adhesion mainly due to toxic effect at the cleavage stage. Contrary to this, however, Hardy et al. showed that when compared with embryos from patients with tubal disease, embryos from PCOS patients progressed to the blastocyst stage at a similar rate. Implantation and pregnancy rates were also similar (Hardy et al., 1995).

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Data from oocyte donation cycles where the donor has polycystic ovaries, and that yield a large number of oocytes, show that implantation of the embryo in the recipient where the endometrium is artificially prepared is not impaired (Pena et al., 2002). Furthermore, in subsequent frozen–thawed embryo transfer cycles, embryos from fresh cycles with high oestradiol concentrations implanted at a similar efficiency compared with embryos derived from fresh cycles with lower oestradiol concentrations (Yu Ng et al., 2000). Simon et al. (1998) showed an increased uterine receptivity when they

compared step-down FSH regimens to conventional regimens in high responder patients. In conclusion, there is preclinical and clinical data to suggest that oocyte and embryo quality and implantation may be impaired in the PCOS patient treated with assisted reproduction. However, not all results are in agreement, and clinical outcome with IVF is at least equivalent to other infertility factors. If there is an actual decline in oocyte quality and fertilization rates, this is compensated by the increased number of oocytes that are retrieved. For clinical purposes, in the PCOS patient undergoing ovarian stimulation the following are recommended: (i) The use of GnRHa in a long protocol to effectively suppress LH concentrations. (ii) The use of step-down gonadotrophin regimens to stimulate the ovaries. (iii) Coasting when oestradiol concentrations are very high. (iv) Insulin-sensitizing medications in the hyperinsulinaemic insulin-resistant patient.

In-vitro maturation of oocytes If ovaries are not stimulated, they will not be hyperstimulated. In this sense, IVM of the oocytes has evolved as an alternative in PCO patients, since it entails no stimulation. Germinal vesicle stage oocytes are retrieved from antral follicles 2–10 mm diameter and IVM is performed until the M-II stage. The advantages of IVM include simplification of treatment, avoidance of the side-effects associated with the use of gonadotrophins and thus reduction in treatment costs due to minimal amount of medication that is used. The first pregnancy with IVM in a patient with PCOS was reported by Trounson et al. in 1994, and many other cases have since been published (Trounson et al., 1994; Durunzi et al., 1995; Chian et al., 1999; Cobo et al., 1999). However, pregnancy rates with IVM have remained relatively low when compared with stimulated IVF in the PCOS patient (Barnes et al., 1996; Cha et al., 2000). The number of immature oocytes retrieved for IVM is related to the number of antral follicles visualized at baseline ultrasonography. Oocytes are retrieved from about 50% of all follicles >2 mm diameter seen at ultrasonography. Therefore the presence of PCO provides a better source of antral follicles, which can be recruited for IVM. Pregnancy rate is found to be significantly higher in women when the number of retrieved oocytes is > 10. Since patients with normal ovaries have fewer antral follicles, fewer oocytes are retrieved and the pregnancy rate is correspondingly lower. The role of mild ovarian stimulation to increase the yield of immature oocytes in women with normal ovaries is contradictory. Two studies have not found any increase in the number of oocytes obtained per aspiration or the maturation or cleavage rate following priming with rec-FSH compared with no stimulation (Mikkelsen et al., 1999; Trounson et al., 2001). In contrast, Wynn et al. reported an increase in both number of oocytes retrieved and maturation rate with mild ovarian stimulation (Wynn et al., 1998). Tan and Child reported 56 patients who underwent a total of 74 IVM cycles. The mean number of oocytes retrieved was 9.1, maturation rate was 81.7%, fertilization rate 83.1%, cleavage

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

rate 90.6%, mean number of embryos transferred 2.7, clinical pregnancy rate per cycle started 24.3%, and clinical pregnancy rate per embryo transfer 25.7% (Tan and Child, 2002). IVM gives reasonable pregnancy rates in women with PCO, and should be considered as a treatment option in this group of women if they require treatment with IVF. Methods of increasing the yield of oocytes in women with normal ovaries and improving implantation rates of IVM embryos will surely result in an expansion in the use of this promising technology.

Conclusions It can be concluded that the outcome of assisted reproduction in the PCOS patient is similar to matched controls treated for other indications. Furthermore, the presence of polycystic ovaries may confer an advantage regarding the number of oocytes retrieved and the number of embryos available for transfer and cryopreservation. However, there are unique features of PCOS that complicate the course of the treatment. Ovarian stimulation is especially difficult in these patients due to a serious risk of severe hyperstimulation. Coasting and other measures are usually necessary to prevent the occurrence of life threatening complications. Although some concerns regarding oocyte and embryo quality have been voiced, these do not appear to significantly affect clinical outcome. In-vitro maturation of oocytes retrieved from non-stimulated or mildly stimulated cycles may in future become the first line treatment option when assisted reproduction is indicated in these difficult patients.

References Abdel-Gadir A, Khatim M, Mowafi R et al. 1992 Implications of ultrasonically diagnosed polycystic ovaries. I. Correlation with basal hormonal profiles. Human Reproduction 7, 453–457. Aboulghar MA, Mansour RT, Serour GI et al. 1997 Oocyte quality in patients with severe ovarian hyperstimulation syndrome. Fertility and Sterility 68, 1017–1021. Abramov Y, Barak V, Nisman B, Schenker J 1997 Vascular endothelial growth factor plasma levels correlate to the clinical picture in severe ovarian hyperstimulation syndrome. Fertility and Sterility 67, 261–265. Abramov Y, Fatum M, Abrahamov D, Schenker JG 2001 Hydroxyethylstarch versus human albumin for the treatment of severe ovarian hyperstimulation syndrome: a preliminary report. Fertility and Sterility 75, 1228–1230. Adams J, Polson D, Abdulwahid N et al. 1985 Multifollicular ovaries: clinical and endocrine features and response to pulsatile gonadotropin releasing hormone. Lancet ii, 1375–1379. Agrawal R, Conway G, Sladkevicius P et al. 1998 Serum vascular endothelial growth factor and Doppler blood flow velocities in invitro fertilization: relevance to ovarian hyperstimulation syndrome and polycystic ovaries. Fertility and Sterility 70, 651–658. Agrawal R, Tan SL, Wild S et al. 1999 Serum vascular endothelial growth factor concentrations in in-vitro fertilization cycles predict the risk of ovarian hyperstimulation syndrome. Fertility and Sterility 71, 287–293. Akagbosu F, Marcus S, Abusheika N et al. 1998 Does ovarian hyperstimulation syndrome affect the quality of oocytes. Human Reproduction 13, 2583–2584. Al-Inany H, Aboulghar MA 2002 GnRH antagonists in assisted reproduction: a Cochrane review. Human Reproduction 17, 874–885. Al-Inany H, Aboulghar MA, Mansour RT, Serour GI 2002 Metaanalyses of recombinant versus urinary derived FSH: an update.

Human Reproduction 18, 305–313. Ashkenazi J, Farhi J, Orvieto R et al. 1995 Polycystic ovary syndrome patients as oocyte donors: the effect of ovarian stimulation protocol on the implantation rate of the recipient. Fertility and Sterility 64, 564–567. Balen AH 1993 Hypersecretion of luteinizing hormone and the polycystic ovary syndrome. Human Reproduction 8 (suppl. 2), 123–128. Balen AH, Tan SL, MacDougall J, Jacobs HS 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. Bancsi L, Broekmans F, Eijlmans M et al. 2002 Predictors of poor ovarian response in in-vitro fertilization: a prospective study comparing basal markers of ovarian reserve. Fertility and Sterility 77, 328–336. Barnes FL, Kausche A, Tiglias J et al. 1996 Production of embryos from in vitro-matured primary human oocytes. Fertility and Sterility 65, 1151–1156. Cano F, Garcia-Velasco JA, Millet A et al. 1997 Oocyte quality in polycystic ovaries revisited: identification of a particular subgroup of women. Journal of Assisted Reproduction and Genetics 14, 254–261. Carmina E, Lobo R 1999 Polycystic ovary syndrome: arguably the most common endocrinopathy is associated with significant morbidity in women. Journal of Clinical Endocrinology and Metabolism 84, 1897–1899. Cha KY, Han SY, Chung HM et al. 2000 Pregnancies and deliveries after in-vitro maturation culture followed by in-vitro fertilization and embryo transfer without stimulation in women with polycystic ovary syndrome. Fertility and Sterility 73, 978–983. Chang R 2002 Polycystic ovary syndrome: diagnostic criteria. In: Chang R, Heinder J, Duanif A (eds) Polycystic Ovary Syndrome. Marcel Dekker, New York, pp. 361–365. Chang R, Nakamura R, Judd H, Kaplan S 1983 Insulin resistance in nonobese patients with polycystic ovarian disease. Journal of Clinical Endocrinology and Metabolism 57, 356–359. Chen D, Burmeister L, Goldschlag D, Rosenwaks Z 2003 Ovarian hyperstimulation syndrome: strategies for prevention. Reproductive BioMedicine Online 7, 43–49. Chenette P, Sauer M, Paulson R 1990 Very high serum estradiol levels are not detrimental to clinical outcome of in-vitro fertilization. Fertility and Sterility 54, 858–863. Chian RC, Buckett WM, Too LL, Tan SL 1999 Pregnancies resulting from in-vitro matured oocytes retrieved from patients with polycystic ovary syndrome after priming with human chorionic gonadotropin. Fertility and Sterility 72, 639–642. Child TJ, Abdul-Jalil AK, Gulekli B, Tan SL 2001 In-vitro maturation and fertilization of oocytes from unstimulated normal ovaries, polycystic ovaries, and women with polycystic ovary syndrome. Fertility and Sterility 76, 936–942. Clark A, Thornley B, Tomlinson L et al. 1998 Weight loss in obese infertile women results in improvement in reproductive outcome for all forms of fertility treatment. Human Reproduction 13, 1502–1505. Cobo A, Requena A, Neuspiller F et al. 1999 Maturation in-vitro of oocytes from unstimulated cycles: selection of the optimal day for ovum retrieval based on follicular size. Human Reproduction 14, 1864–1868. Colacurci N, Zullo F, De Franciscis P et al. 1997 In-vitro fertilization following laparoscopic ovarian diathermy in patients with polycystic ovarian syndrome. Acta Obstetricia et Gynecologica Scandinavica 76, 555–558. D’Angelo A, Amso N 2002 ‘Coasting’ (withholding gonadotropins) for preventing ovarian hyperstimulation syndrome. Cochrane Database System Review CD002811. Dale P, Tanbo T, Haug E, Abyholm T 1998 The impact of insulin resistance on the outcome of ovulation induction with low dose follicle stimulating hormone in women with polycystic ovary syndrome. Human Reproduction 13, 567–570. Damario MA, Barmat L, Liu HC et al. 1997 Dual suppression with

427

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

428

oral contraceptives and gonadotropin releasing-hormone agonists improves in-vitro fertilization outcome in high responder patients. Human Reproduction 12, 2359–2365. Daya S 2002 Updated meta-analyses of recombinant follicle stimulating hormone (FSH) versus urinary FSH for ovarian stimulation in assisted reproduction. Fertility and Sterility 77, 711–714. de Jong D, Macklon NS, Mannaerts BM et al. 1998 High dose gonadotropin-releasing hormone antagonist (ganirelix) may prevent ovarian hyperstimulation syndrome caused by ovarian stimulation for in-vitro fertilization. Human Reproduction 13, 573–575. De Leo V, La Marca A, Ditto A et al. 1999 Effects of metformin on gonadotropin induced ovulation in women with polycystic ovary syndrome. Fertility and Sterility 72, 282–285. Delvigne A, Rozenberg S 2002 A qualitative systematic review of coasting, a procedure to avoid ovarian hyperstimulation syndrome in IVF patients. Human Reproduction Update 8, 291–296. Delvigne A, Rozenberg S 2003 Review of clinical course and treatment of ovarian hyperstimulation syndrome (OHSS). Human Reproduction Update 9, 77–96. Doldi N, Marsiglio E, Destefani A et al. 1999 Elevated serum progesterone on the day of HCG administration in IVF is associated with a higher pregnancy rate in polycystic ovary syndrome. Human Reproduction 14, 601–605. Donesky B, Adashi E 1995 Surgically induced ovulation in the polycystic ovary syndrome: wedge resection revisited in the age of laparoscopy. Fertility and Sterility 63, 439–463. Dor J, Shulman A, Levran D et al. 1990 The treatment of patients with polycystic ovarian syndrome by in-vitro fertilization and embryo transfer: a comparison of results with those of patients with tubal infertility. Human Reproduction 5, 816–818. Dunaif A, Graf M, Mandeli J et al. 1987 Characterization of groups of hyperandrogenemic women with acanthosis nigricans, impaired glucose tolerance, and/or hyperinsulinemia. Journal of Clinical Endocrinology and Metabolism 65, 499–507. Dunaif A, Segal K, Futterweit W, Dobrjansky A 1989 Profound peripheral insulin resistance, independent of obesity, in polycystic ovary syndrome. Diabetes 38, 1165–1174. Dunaif A, Segal K, Shelley D et al. 1992 Evidence for distinctive and intrinsic defects in insulin action in polycystic ovary syndrome. Diabetes 41, 1257–1266. Durunzi K, Saniga E, Lanzendorf S 1995 The relationship between size and maturation in-vitro in the unstimulated human oocyte. Fertility and Sterility 63, 404–406. Egbase PE, Al-Sharhan M, Grudzinskas JG 2002 ‘Early coasting’ in patients with polycystic ovarian syndrome is consistent with good clinical outcome. Human Reproduction 17, 1212–1216. Elvin J, Yan C, Matzuk M 2000 Oocytes expressed TGF-beta superfamily members in female fertility. Molecular and Cellular Endocrinology 159, 1–5. Engmann L, Maconochie N, Sladkevicius P et al. 1999 The outcome of in-vitro fertilization treatment in women with sonographic evidence of polycystic ovarian morphology. Human Reproduction 14, 167–171. European Recombinant LH Study Group 2001 Human recombinant luteinizing hormone is as effective as but safer than, urinary chorionic gonadotropin in inducing final follicular maturation and ovulation in in-vitro fertilization procedures: results of a multicenter double-blind study. Journal of Clinical Endocrinology and Metabolism 86, 2607–2618. Farhi J, Nosanchuk J, Silverberg S 1986 Endometrial adenocarcinoma in women under 25 years of age. Obstetrics and Gynecology 68, 741–745. Fatemi HM, Platteau P, Albano C et al. 2002 Rescue IVF and coasting with the use of a GnRH antagonist after ovulation induction. Reproductive BioMedicine Online 5, 273–275. Fedorcsak P, Storeng R, Dale PO et al. 2000 Impaired insulin action on granulosa-lutein cells in women with polycystic ovary syndrome and insulin resistance. Gynecologic Endocrinology 14, 327–336.

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. Fedorcsak P, Dale PO, Storeng R et al. 2003 The effect of metformin on ovarian stimulation and in-vitro fertilization in insulinresistant women with polycystic ovary syndrome: an open-label randomized crossover trial. Gynecologic Endocrinology 17, 207–214. Filho T, Baracat E, Lee T et al. 2002 Aberrant expression of growth differentiation factor-9 in oocytes of women with polycystic ovary syndrome. Journal of Clinical Endocrinology and Metabolism 87, 1337–1344. Franks S, Roberts R, Hardy K 2003 Gonadotropin regimens and oocyte quality in women with polycystic ovaries. Reproductive BioMedicine Online 6, 181–184. Glueck CJ, Phillips H, Cameron D et al. 2001 Continuing metformin throughout pregnancy in women with polycystic ovary syndrome appears to safely reduce first trimester spontaneous abortion: a pilot study. Fertility and Sterility 75, 46–52. Goldfarb JM, Desai N 2003 Follitropin alpha versus human menopausal gonadotropin in an in vitro fertilization program. Fertility and Sterility 80, 1094–1099. Grochowski D, Wolczynski S, Kuczynski W et al. 2001 Correctly timed coasting reduces the risk of ovarian hyperstimulation syndrome and gives good cycle outcome in an in-vitro fertilization program. Gynecologic Endocrinology 15, 234–238. Hamilton-Fairley D, Kiddy D, Watson H et al. 1991 Low dose gonadotropin therapy for induction of ovulation in 100 women with polycystic ovary syndrome. Human Reproduction 6, 1095–1099. Hardy K, Robinson FM, Paraschos T et al. 1995 Normal development and metabolic activity of preimplantation embryos in-vitro from patients with polycystic ovaries. Human Reproduction 10, 2125–2135. Homburg R, Howles C 1999 Low dose FSH therapy for anovulatory infertility associated with polycystic ovary syndrome: rationale, reflections and refinements. Human Reproduction Update 5, 493–499. Homburg R, Insler V 2002 Ovulation induction in perspective. Human Reproduction Update 8, 449–462. Homburg R, Armar N, Eschel A et al. 1988 Influence of serum luteinizing hormone concentrations on ovulation, conception, and early pregnancy loss in polycystic ovary syndrome. British Medical Journal 297, 1024–1026. Homburg R, Eshel A, Kilborn J et al. 1990 Combined luteinizing hormone releasing analogue and exogenous gonadotropins for the treatment of infertility associated with polycystic ovaries. Human Reproduction 5, 32–37. Homburg R, Berkowitz D, Levy T et al. 1993a In-vitro fertilization and embryo transfer for the treatment of infertility associated with polycystic ovary syndrome. Fertility and Sterility 60, 858–863. Homburg R, Levy T, Berkovitz D et al. 1993b Gonadotropinreleasing hormone agonist reduces the miscarriage rate for pregnancies achieved in women with polycystic ovarian syndrome. Fertility and Sterility 59, 527–531. Howles C, Macnamee MC, Edwards R et al. 1986 Effect of high tonic concentrations of luteinizing hormone on outcome of invitro fertilization. Lancet ii, 521–522. Huber-Buchholz M, Carey D, Norman RJ 1999 Restoration of reproductive potential by lifestyle modification in obese polycystic ovary syndrome: role of insulin sensitivity and luteinizing hormone. Journal of Clinical Endocrinology and Metabolism 84, 1470–1474. Hughes E, Fedorkow D, Daya S et al. 1992 The routine use of gonadotropin releasing hormone agonists prior to in-vitro fertilization and gamete intrafallopian transfer: a meta-analysis of randomized trials. Fertility and Sterility 58, 888–896. Hughes E, Collins J, Vanderkerckhove P 2000 Gonadotropin releasing hormone analogue as an adjunct to gonadotropin

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

therapy for clomiphene resistant polycystic ovarian syndrome (Cochrane Review). The Cochrane Library 2 Update Software, Oxford. Hugues JN, Bstandig B, Bry-Gauillard H, Uzan M, Cédrin-Durnerin I 2001 Comparison of the effectiveness of recombinant and urinary FSH preparations in the achievement of follicular selection in chronic anovulation. Reproductive BioMedicine Online 3, 195–198. Kamat B, Brown L, Manseau E et al. 1995 Expression of vascular endothelial growth factor vascular permeability factor by human granulosa and theca lutein cells: role in corpus luteum development. American Journal of Pathology 146, 157–165. Kodama H, Fukuda J, Karube H et al. 1995 High incidence of embryo transfer cancellations in patients with polycystic ovarian syndrome. Human Reproduction 10, 1962–1967. Konig E, Bussen S, Sutterlin M, Steck T 1998 Prophylactic intravenous hydroxyethylstarch solution prevents moderatesevere ovarian hyperstimulation in in-vitro fertilization patients: a prospective, randomized, double-blind and placebo-controlled study. Human Reproduction 13, 2421–2424. Krasnow J, Berga S, Guzick D et al. 1996 Vascular permeability factor and vascular endothelial growth factor in ovarian hyperstimulation syndrome: a preliminary report. Fertility and Sterility 65, 552–555. Levinsohn-Tavor O, Friedler S, Schachter M et al. 2003 Coasting – what is the best formula? Human Reproduction 18, 937–940. Lindahl B, Willen R 1985 Endometrial hyperplasia: clinicopathologic considerations of a prospective randomized study after abrasion or high dose gestagen treatment. Results of 2 years follow-up of 292 patients. Anticancer Research 11, 403–411. Lord J, Flight I, Norman RJ 2003 Metformin in polycystic ovary syndrome: systematic review and meta analysis. British Medical Journal 327, 951–957. Ludwig M, Finas DF, al-Hasani S et al. 1999 Oocyte quality and treatment outcome in intracytoplasmic sperm injection cycles of polycystic ovarian syndrome patients. Human Reproduction 14, 354–358. Ma WG, Song H, Das SK et al. 2003 Estrogen is a critical determinant that specifies the duration of the window of uterine receptivity for implantation. Proceedings of the National Academy of Sciences of the USA 100, 2963–2968. MacDougall MJ, Tan SL, Balen A, Jacobs HS 1993 A controlled study comparing patients with and without polycystic ovaries undergoing in-vitro fertilization. Human Reproduction 8, 233–237. Marci R, Senn A, Dessole S et al. 2001 A low-dose stimulation protocol using highly purified follicle-stimulating hormone can lead to high pregnancy rates in in-vitro fertilization patients with polycystic ovaries who are at risk of a high ovarian response to gonadotropins. Fertility and Sterility 75, 1131–1135. McClure N, Healy DL, Paw R et al. 1994 Vascular endothelial growth factor as a capillary permeability agent in ovarian hyperstimulation syndrome. Lancet 344, 235–243. Meier D, Schenker J 1996 The link between infertility and cancer: epidemiology and possible etiologies. Human Reproduction Update 2, 63–75. Meldrum D 1989 GnRH agonists as adjuncts for in-vitro fertilization. Obstetrical and Gynecological Survey 44, 314–316. Mikkelsen AL, Lindenberg S 2001 Morphology of in-vitro matured oocytes: impact on fertility potential and embryo quality. Human Reproduction 16, 1714–1718. Mikkelsen A, Smith S, Lindenberg S 1999 In-vitro maturation of human oocytes from regular menstruating women may be successful without follicle stimulating hormone priming. Human Reproduction 14, 1847–1851. Mulders A, Laven J, Imani B et al. 2003 IVF outcome in anovulatory infertility (WHO group 2) including polycystic ovary syndrome following previous unsuccessful ovulation induction. Reproductive BioMedicine Online 7, 50–58. Nestler J, Jakubowicz D, Evans W, Pasquali R 1998 Effects of metformin on spontaneous and clomiphene induced ovulation in

polycystic ovary syndrome. New England Journal of Medicine 338, 1876–1880. Nestler J, Stovall D, Akhter N et al. 2002 Strategies for the use of insulin-sensitizing drugs to treat infertility in women with polycystic ovary syndrome. Fertility and Sterility 77, 209–215. Neulen J, Zhaoping Y, Raczek S et al. 1995 Human chorionic gonadotropin dependent expression of vascular endothelial growth factor in human granulosa cells and importance in ovarian hyperstimulation syndrome. Journal of Clinical Endocrinology and Metabolism 80, 1967–1971. Nugent D, Vanderkerckhove P, Hughes E et al. 2000 Gonadotropin therapy for ovulation induction in subfertility associated with polycystic ovary syndrome (Cochrane review). The Cochrane Library 1 (Update Software, Oxford), Ohata Y, Harada T, Ito M et al. 2000 Coasting may reduce the severity of the ovarian hyperstimulation syndrome in patients with polycystic ovary syndrome. Gynecologic and Obstetric Investigation 50, 186–188. Pasquali R, Antenucci D, Casimirri F et al. 1989 Clinical and hormonal charateristics of obese amenorrheic hyperandrogenic women before and after weight loss. Journal of Clinical Endocrinology and Metabolism 68, 173–179. Pellicer A, Valbuena D, Cano F et al. 1996 Lower implantation rates in high responders: evidence for an altered endocrine milieu during the preimplantation period. Fertility and Sterility 65, 1190–1195. Pena J, Chang P, Chan L et al. 2002 Supraphysiological estradiol levels do not affect oocyte and embryo quality in oocyte donation cycles. Human Reproduction 17, 83–87. Polson D, Wadsworth J, Adams J, Franks S 1988 Polycystic ovaries: a common finding in normal women. Lancet i, 870–872. Regan L, Owen EJ, Jacobs H 1990 Hypersecretion of luteinizing hormone, infertility, and miscarriage. Lancet ii, 1141–1144. Rimington MR, Walker SM, Shaw RW 1997 The use of laparoscopic ovarian electrocautery in preventing cancellation of in-vitro fertilization treatment cycles due to risk of ovarian hyperstimulation syndrome in women with polycystic ovaries. Human Reproduction 12, 1443–1447. Sengoku K, Tamate K, Takuma N et al. 1997 The chromosomal normality of unfertilized oocytes from patients with polycystic ovarian syndrome. Human Reproduction 12, 474–477. Sharara FI, McClamrock H 1999 High estradiol levels and high oocyte yield are not detrimental to in-vitro fertilization outcome. Fertility and Sterility 72, 401–405. Sher G, Zouves C, Feinman M, Maassarani G 1995 ‘Prolonged coasting’: an effective method for preventing severe ovarian hyperstimulation syndrome in patients undergoing in-vitro fertilization. Human Reproduction 10, 3107–3109. Simon C, Garcia-Velasco JA, Valbuena D et al. 1998 Increasing uterine receptivity by decreasing estradiol levels during the preimplantation period in high responders with the use of a follicle-stimulating hormone step down regimen. Fertility and Sterility 70, 234–239. Stadtmauer LA, Toma SK, Riehl RM, Talbert LM 2001 Metformin treatment of patients with polycystic ovary syndrome undergoing in-vitro fertilization improves outcomes and is associated with modulation of the insulin-like growth factors. Fertility and Sterility 75, 505–509. Stadtmauer LA, Toma SK, Riehl RM, Talbert LM 2002 Impact of metformin therapy on ovarian stimulation and outcome in coasted patients with polycystic ovary syndrome undergoing in-vitro fertilization. Reproductive BioMedicine Online 5, 112–116. Stanger J, Yovich J 1985 Reduced in-vitro fertilization of human oocytes from patients with raised basal luteinizing hormone levels during the follicular phase. British Journal of Obstetrics and Gyneacology 92, 385–393. Tan SL, Child TJ 2002 In-vitro maturation of oocytes from unstimulated polycystic ovaries. Reproductive BioMedicine Online 4 (suppl. 1), 18–23. Tomas C, Nuojua-Huttunen S, Martikainen H 1997 Pretreatment transvaginal ultrasound examination predicts ovarian

429

Outlook - Assisted reproduction to treat PCOS - B Urman et al.

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responsiveness to gonadotropins in in-vitro fertilization. Human Reproduction 12, 220–223. Tozer AJ, Al-Shawaf T, Zosmer A et al. 2001 Does laparoscopic ovarian diathermy affect the outcome of IVF–embryo transfer in women with polycystic ovarian syndrome? A retrospective comparative study. Human Reproduction 16, 91–95. Trounson A, Wood C, Kausche A 1994 In-vitro maturation and the fertilization and developmental competence of oocytes recovered from untreated polycystic ovarian patients. Fertility and Sterility 62, 353–362. Trounson A, Anderiesz C, Jones G 2001 Maturation of human oocytes in-vitro and their developmental competence. Reproduction 121, 51–75. Turhan NO, Artini PG, D-Ambrogio G et al. 1993 A comparative study of three ovulation induction protocols in polycystic ovarian disease patients in an in-vitro fertilization/embryo transfer program. Journal of Assisted Reproduction and Genetics 10, 15–20. Urman B, Fluker MR, Yuen BH et al. 1992 The outcome of in-vitro fertilization and embryo transfer in women with polycystic ovary syndrome failing to conceive after ovulation induction with exogenous gonadotropins. Fertility and Sterility 57, 1269–1273. Urman B, Sarac E, Dogan L, Gurgan T 1997 Pregnancy in infertile PCOD patients. Complications and outcome. Journal of Reproductive Medicine 42, 501–505. Valbuena D, Martin J, de-Pablo JL et al. 2001 Increasing levels of estradiol are deleterious to embryonic implantation because they directly affect the embryo. Fertility and Sterility 76, 962–968. Van der Meer M, Hompes P, de Boer J et al. 1998 Cohort size rather than FSH threshold determines ovarian sensitivity in polycystic ovary syndrome. Journal of Clinical Endocrinology and Metabolism 83, 423–426. van Wely M, Bayram N, van der Veen F 2003a Recombinant FSH in alternative doses versus urinary gonadotropins for ovulation induction in subfertility associated with polycystic ovary syndrome: a systematic review based on a Cochrane review. Human Reproduction 18, 1143–1149. van Wely M, Westergaard, LG, Bossuyt PM, van der Veen F 2003b Effectiveness of human menopausal gonadotropin versus recombinant follicle stimulating hormone for controlled ovarian hyperstimulation in assisted reproductive cycles: a meta-analysis. Fertility and Sterility 80, 1086–1093. Waldenstrom U, Kahn J, Marsk L, Nilsson S 1999 High pregnancy rates and successful prevention of severe ovarian hyperstimulation syndrome by ‘prolonged coasting’ of very hyperstimulated patients: a multicenter study. Human Reproduction 14, 294–297. Wang C, Gemzell C 1980 The use of human gonadotropins for the induction of ovulation in women with polycystic ovarian disease. Fertility and Sterility 33, 479–486. Wang JX, Davies MJ, Norman RJ 2000 Body mass and probability of pregnancy during assisted reproduction treatment: retrospective study. British Medical Journal 321, 1320–1321. Wang JX, Davies MJ, Norman RJ 2001 Polycystic ovarian syndrome and the risk of spontaneous abortion following assisted reproductive technology treatment. Human Reproduction 16, 2606–2609. White D, Polson D, Kiddy D et al. 1996 Induction of ovulation with low-dose gonadotropins in polycystic ovary syndrome: an analysis of 109 pregnancies in 225 women. Journal of Clinical Endocrinology and Metabolism 81, 3821–3824. Willis D, Watson H, Mason H et al. 1998 Premature responsiveness to luteinizing hormone in granulosa cells from anovulatory women with polycystic ovary syndrome: relevance to mechanism of anovulation. Journal of Clinical Endocrinology and Metabolism 83, 3484–3491. Wynn P, Picton H, Krapez J et al. 1998 Randomized study of oocytes matured after collection from unstimulated or mildly stimulated patients. Human Reproduction 13, 3132–3138. Yarali H, Bukulmez O, Gurgan T Urinary follicle-stimulating hormone (FSH) versus recombinant FSH in clomiphene citrate-

resistant, normogonadotropic, chronic anovulation: a prospective randomized study Fertility and Sterility 72, 276–281. Yu Ng E, Yeung W, Yee L et al. 2000 High serum estradiol concentrations in fresh IVF cycles do not impair implantation and pregnancy rates in subsequent frozen-thawed embryo transfer cycles. Human Reproduction 15, 250–255. Zawadski J, Dunaif A 1992 Diagnostic criteria for polycystic ovary syndrome: towards a rational approach. In: Duanif A, Givens J, Haseltine F, Merriam G (eds) Polycystic Ovary Syndrome. Blackwell, Boston, pp. 377–384.

Paper based on contribution presented at the ‘PCOS Symposium: Current Concepts, Treatment and Ovulation Induction’ in Antalya, Turkey, September 2003. Received 12 January 2004; refereed 29 January 2004; accepted 2 February 2004.