FERTILITY AND STERILITY VOL. 81, NO. 4, APRIL 2004 Copyright 2004 American Society for Reproductive Medicine Published by Elsevier Inc. Printed on acid-free paper in U.S.A. Minimal stimulation using recombinant follicle-stimulating hormone and a gonadotropin-releasing hormone antagonist in women of advanced age Andrea Weghofer, M.D., a Markus Margreiter, M.D., a Sami Bassim, M.D., a Ursula Sevelda, M.D., b Elke Beilhack, M.D., b and Wilfried Feichtinger, M.D., Ph.D. a Wunschbabyzentrum Institute for Sterility Treatment, Vienna, Austria Received August 12, 2002; revised and accepted September 4, 2003. Reprint requests: Wilfried Feichtinger, M. D., Ph.D., Wunschbabyzentrum Institute for Sterility Treatment, Lainzerstrasse 6, A-1130 Vienna, Austria (FAX: 0043-1-877-77-75-34; E-mail: wilfried.feichtinger@ wunschbaby.at). a Wunschbabyzentrum Institute for Sterility Treatment, Vienna, Austria. b Department for Gynaecology and Obstetrics, University of Vienna, Vienna, Austria. 0015-0282/04/$30.00 doi:10.1016/j.fertnstert.2003. 09.050 Objective: To determine whether minimal stimulation with short-term application of low-dose recombinant follicle-stimulating hormone (FSH) together with a gonadotropin-releasing hormone (GnRH) antagonist represents a cost-effective treatment regimen for patients with elevated FSH levels, aged 40 and above. Design: Retrospective cohort study. Setting: Academically affiliated private in vitro fertilization (IVF) program. Patient(s): Eighty-five IVF cycles using minimal ovarian stimulation and 85 cycles with a standard longstimulation protocol, conducted between January 2000 and January 2002, in women aged 40 and above who had slightly increased FSH levels. Intervention(s): Patients on the long protocol underwent standard cycle monitoring and stimulation. In contrast, women with minimal stimulation had transvaginal sonography initiated on day 8 of the menstrual cycle and at a follicle size of 13 mm. We administered 0.25 mg of GnRH antagonist and 75 IU recombinant FSH daily until ovulation induction. Main Outcome Measure(s): Numbers of oocytes, and rates of cancellation and pregnancy. Result(s): Minimal stimulation cycles resulted in a clinical pregnancy rate of 8.2% per started cycle and 10% per embryo transfer (ET), whereas the control group yielded a clinical pregnancy rate of 10.6% per started cycle and of 10.7% per ET (not statistically significant). Conclusion(s): In women aged 40 and above with abnormal FSH levels, minimal stimulation protocol achieves similar pregnancy rates to a standard protocol, and thus represents a cost-effective alternative. (Fertil Steril 2004;81:1002 6. 2004 by American Society for Reproductive Medicine.) Key Words: Age, cost-effective, in vitro fertilization, FSH, GnRH antagonist, minimal stimulation, natural cycle, spontaneous cycle The first successful pregnancy following in vitro fertilization (IVF) occurred during a natural cycle. Since then, increasing efficiency of assisted reproductive procedures has been obtained by steadily more expensive hormone stimulation protocols and improved techniques for gamete and embryo handling (1). However, for women of advanced age with abnormally increased FSH levels, standardized hormonal stimulation often represents a cost-intensive procedure with a low success rate. In Austria, the IVF-Fonds, a governmentrelated fund, in cooperation with the social insurance fund, covers 70% of the treatment costs for infertile women under age 40. The lack of financial support for women aged 40 and above leads to greater expense for these patients when undergoing a standard stimulation regimen. Therefore, we searched for a cost-effective stimulation protocol for women of advanced age (2, 3). The minimal stimulated cycle with a short-term daily application of a gonadotropin-releasing hormone (GnRH) antagonist (0.25 mg of Cetrorelix [Cetrotide in Austria]; Serono Europe Ltd., London, U.K.), together with 75 IU of recombinant FSH (Gonal F, Ares-Serono Europe, Ltd., London, U.K.) before ovulation seems to meet the criteria. Such a minimal protocol enables treatment with a 70% reduced requirement for med- 1002
ication compared with the standard long-protocol stimulation. The purpose of our study was to determine whether minimal stimulation can be seen as a cost-saving alternative to standardized hormonal regimens for women aged 40 and above who have slightly elevated FSH levels. We compared the pregnancy rates achieved in minimally stimulated cycles with those obtained under standard long-protocol stimulation. MATERIALS AND METHODS Study Design and Patients Our retrospective cohort study was performed at a private center for infertility treatment. We analyzed a total of 85 women, aged 40 and above with slightly elevated levels of FSH, who underwent a minimal stimulation protocol between January 2000 and January 2002. Patients were selected consecutively. As a nonrandomized control group, we selected 85 patients who underwent the standard long-protocol stimulation at the same time, matched according to age, FSH levels, diagnosis, and day of embryo transfer (ET). In both groups, only one cycle per patient was analyzed. Because the present study is based on retrospective data analysis, no institutional review board approval had to be obtained. Ovarian Stimulation and Fertilization Before assignment of a stimulation regimen, a hormonal evaluation was performed for all women in the early follicular phase (days 2 to 3 of menstrual cycle), which included measurement of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) levels. In the minimal stimulation group, cycle monitoring was initiated on day 8 by transvaginal sonography. Thickness of the endometrium was measured as the maximum width of the two endometrial layers in a sagittal plane between the inner margins of the underlying sonolucent layers. When a follicle of at least 13 mm was seen in an ovary, a single dose of a GnRH antagonist (Cetrorelix, 0.25 mg) was administered, combined with 75 IU FSH (Gonal F) subcutaneously. Afterward the women were monitored daily; 0.25 mg Cetrorelix and 75 IU Gonal F were injected once a day, including the day of ovulation induction. When a follicle diameter of 18 to 20 mm was achieved, the patients were advised to inject 10 000 IU of human chorionic gonadotropin (hcg, Pregnyl; Organon, Holland) at a pre-fixed time in the evening. Thirty-six hours later, a transvaginal, ultrasoundguided oocyte retrieval was performed. Intracytoplasmic sperm injection (ICSI) was performed electively because of the expected small number of oocytes. According to cleavage and morphologic characteristics, the embryos were transferred between days 2 and 5. The luteal phase was supported by a daily administration of 30 mg of Dydrogesterone (Duphaston). Patients in the control group underwent the standard long-protocol monitoring and stimulation. According to their indication for sterility treatment, either IVF or ICSI was performed. A clinical pregnancy was defined as the presence of fetal cardiac activity beyond 8 weeks of gestation. Further fetal monitoring was performed by the woman s obstetrician. Statistical Analysis According to previous experience in our IVF program, the pregnancy rates per ET in both treatment groups were expected to be about 10%. A difference of 30% between study groups was considered statistically significant. To have an 80% chance of detecting such a difference at an overall significance level of 5%, 71 subjects per study arm were required. To allow for dropouts, we sought to recruit 85 patients per treatment group. Statistical analysis was performed with the Stat View SE program (Abacus Concepts., Berkeley, CA), using the contingency table test to compare the outcomes of the stimulation protocols used. P.05 was considered statistically significant. RESULTS The mean ages of the women were 42.0 years 1.5 years for the minimal stimulation group and 41.9 years 1.5 years for the long protocol group (P.84; not statistically significant). The FSH levels in patients undergoing minimal stimulation were 8.3 1.8 mu/ml, and 8.1 2.3 mu/ml in the control group (Table 1). In patients undergoing minimal stimulation, the indications for IVF were male factor infertility in 57%, tubal factor infertility in 27%, and a combination of factors in 6%. Within the control group, male factor infertility was diagnosed in 58%, tubal factor infertility in 21%, and combined infertility factors in 6% (P.83; not statistically significant) (Table 2). A mean of 1.1 0.4 oocytes was retrieved in minimally stimulated cycles, whereas 5.5 3.3 oocytes were retrieved under the long-protocol stimulation (P.05). In the minimal stimulation cycles, 18% of the treatment procedures had to be cancelled before ET. Reasons for cancellation were either insufficient follicular growth (9%) or premature LH surge (9%). The cancellation rate under long-protocol stimulation was 1% (P.05). Within both groups, ET was performed on days 2 to 5. The day of ET was selected according to embryo cleavage and morphologic features. The mean number of embryos transferred was 1.0 0.2 in the minimal stimulation group and 2.5 1.0 in the control group (P.05). In the control group, supernumerary embryos for cryopreservation were obtained in two cycles (see Table 1). Cycles with minimal stimulation resulted in a clinical pregnancy rate of 8.2% per started cycle and 10% per ET. FERTILITY & STERILITY 1003
TABLE 1 Patient characteristics and cycle parameters. Characteristic Minimal stimulation P value Age (years) 42.0 1.5 [40 47] 41.9 1.5 [40 47].84 FSH (mu/ml) 8.3 1.8 [4.9 15.3] 8.1 2.3 [5.2 15.7].46 No. of oocytes retrieved 1.1 0.4 [1 3] 5.5 3.3 [1 21].05 Day of embryo transfer 2.5 0.8 [2 5] 2.7 1.1 [2 5].18 No. of embryos transferred 1.0 0.2 [1 2] 2.5 1.0 [1 4].05 Cancellation rate (%) 18% 1%.05 No. of cycles with embryos for 0 2 cryopreservation No. of cryopreserved embryos 0 2.5 [2 3] The analysis of the control cycles yielded a clinical pregnancy rate of 10.6% per started cycle and 10.7% per ET (Fig. 1). These differences were not statistically different (Table 3). The cycles stimulated with the minimal protocol resulted only in singleton pregnancies. In the control group, 7.1% singleton and 3.6% twin pregnancies per ET occurred (i.e. 33.3% twin pregnancies). No supernumerary embryos could be obtained for cryopreservation in the minimal stimulation group. In the long-protocol group, the transfer of cryopreserved embryos resulted in a cumulative pregnancy rate of 11.6% (see Table 3). DISCUSSION Standardized hormonal stimulation in women with poor ovarian reserve often results in low pregnancy rates and high expenditure because of the high medication costs (4 7). This study suggests that patients who do not have adequate insurance support for IVF may benefit from a minimal stimulation protocol with its restricted use of gonadotropins (8, 9). However, minimal stimulation results in a higher cancellation rate (10 12). To reduce cancellation due to premature ovulation, a daily dose of a new GnRH antagonist (Cetrorelix) was administered, starting at a follicle size of 13 mm. To avoid poor oocyte maturation, 75 mu of FSH (Gonal F) was injected simultaneously. This combined treatment was given to ensure optimized follicle development and controllable ovulation (13, 14). It was not always successful; indeed, a spontaneous LH surge was not always prevented through the administration of the GnRH antagonist in minimally stimulated cycles. This might be attributable to estrogen levels high enough to induce an LH increase before the initial administration of the GnRH antagonist (15 19). Therefore, minimally stimulated cycles resulted in a statistically significantly higher cancellation rate compared with the longprotocol stimulation (18% vs. 1%). Minimally stimulated protocols, therefore, may result in fewer ETs, with lower pregnancy rates per started cycle (minimal stimulation: 8.2% pregnancy rate/cycle vs. long protocol: 10.6% pregnancy rate/cycle; P.81, not statistically significant) (20 24). However, the analysis of the TABLE 3 Cycle outcome. TABLE 2 Indications for fertility treatment. Outcome Minimal stimulation (n ET 70; n C 70) (n ET 84; n C 86) P value Indication Minimal stimulation Male factor 57% 58% Tubal factor 27% 21% Endometriosis 2% 2% Idiopathic 8% 13% Combination of factors 6% 6% Clinical pregnancy rate per cycle 8.2% 10.6%.81 Clinical pregnancy rate per ET 10% 10.7%.99 Singleton pregnancies per ET 10% 7.1% Twin pregnancies per ET 0% 3.6% Cumulative clinical pregnancy rate per ET 10% 11.6%.95 Note: n ET number of cycles with embryo transfer; n C number of embryo transfers, including cryopreserved embryos. 1004 Weghofer et al. Minimal stimulation in women of advanced age Vol. 81, No. 4, April 2004
FIGURE 1 Minimal stimulation versus long-protocol, comparison of the pregnancy rates per started cycle (black) and per embryo transfer (gray). pregnancy rates per ET did not yield any statistically significant differences (minimal stimulation: 10% per ET vs. long protocol: 10.7% per ET) (see Fig. 1). The low pregnancy rate of both stimulation regimens might, however, be related to the diminished ovarian reserve of these patients. Women of advanced age with normal FSH levels undergoing infertility treatment in our private infertility clinic may generally expect a pregnancy rate of about 20%. Under the minimal stimulation only singleton pregnancies were established, whereas the long-protocol stimulation resulted in a twin pregnancy rate of 33.3%. The latter is, of course, associated with an increased risk of preterm delivery (13). A preferential benefit of the long protocol in women of advanced age can be seen in its improved cumulative outcome as additional pregnancies may be achieved with cryopreserved embryos (long protocol: 11.6% vs. minimal protocol: 10%; P.95, not statistically significant). This does not appear to warrant the dramatically increased cost of such a protocol in comparison with the minimal stimulation protocol. The insufficient control of ovulation induction in patients undergoing minimal stimulation is still in need of improvement, and further studies appear indicated to reduce the cancellation rate of this treatment regimen. Acknowledgments: The authors wish to thank the Wunschbaby-Team for their support. References 1. Ingerslev HJ, Hojgaard A, Hindkjaer J, Kesmodel U. A randomised study comparing IVF in the unstimulated cycle with IVF following clomiphene citrate. Hum Reprod 2001;16:696 702. 2. Thornton MH, Francis MM, Paulson RJ. Immature oocyte retrieval: lessons from unstimulated IVF cycles. Fertil Steril 1998;70:647 50. 3. Monks NJ, Turner K, Hooper MAK, Kumar A, Verma S, Lenton EA. Development of embryos from natural cycle in-vitro fertilization: impact of medium type and female infertility factors. Hum Reprod 1993; 8:266 71. FERTILITY & STERILITY 1005
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