A prospective, randomized, controlled trial comparing highly purified hMG with recombinant FSH in women undergoing ICSI: ovarian response and clinical outcomes

Z. Kilani1, A. Dakkak1, S. Ghunaim1, G.E. Cognigni2, C. Tabarelli2, L. Parmegiani2 and M. Filicori2,3

1 Farah Hospital, Amman, Jordan and 2 Reproductive Endocrinology Center, University of Bologna, Via Massarenti 13 40138, Bologna, Italy

3 To whom correspondence should be addressed. e-mail: marco.filicori{at}unibo.it


    Abstract
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
BACKGROUND: To assess the clinical profile and efficacy in assisted reproductive treatment of a new human-derived highly purified (HP) menotropin, we compared HP hMG and recombinant (r) FSH{alpha} use in ICSI within a prospective, randomized, controlled study. METHODS: 100 infertile women were treated with HP hMG (50 patients) or rFSH{alpha} (50 patients). All patients received the same daily gonadotrophin dose (150 IU) following GnRH agonist suppression (long regimen) until more than three follicles >17 mm and estradiol (E2) levels >600 pg/ml were reached. Patients were monitored with daily LH, FSH, hCG, estradiol (E2), progesterone, and testosterone measurements; and alternate day pelvic ultrasound. RESULTS: Treatment duration (11.1 ± 0.4 versus 12.9 ± 0.5 days, P < 0.05) and gonadotrophin dose (22.4 ± 1.0 versus 27.0 ± 1.5 ampoules, P < 0.05) were lower in the HP hMG group. Conversely, peak pre-ovulatory E2 (1342 ± 127 versus 933 ± 109 pg/ml, P < 0.005); and area under the curve of E2 (3491 ± 350 versus 2602 ± 349 pg/ml.day, P < 0.05), immunoreactive serum FSH (65.9 ± 2.1 versus 48.8 ± 1.8 IU/l.day, P < 0.001). and hCG (1.7 ± 0.3 versus 0.0 ± 0.0 IU/l/day, P < 0.001) during treatment were higher in the HP hMG group. Cycle cancellation rates, transferred embryo number, pregnancy rates per started cycle (30 versus 28%) and per embryo transfer (35 versus 35%) and miscarriage rates (6 versus 6%) were not significantly different. CONCLUSIONS: HP hMG treatment was associated with: (i) a more efficient patient response, as reflected by reduced treatment duration and gonadotrophin requirements; (ii) increased serum levels of hCG, E2, and immunoreactive FSH during treatment; (iii) an ICSI outcome indistinguishable from rFSH{alpha}.

Key words: highly purified hMG/ICSI/LH/ovulation induction/recombinant FSH


    Introduction
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
In the last decade the number of gonadotrophins available for ovulation induction and controlled ovarian stimulation (COS) has rapidly expanded. In addition to the introduction of various types of recombinant (r) preparations such as rFSH ({alpha} and {beta}), rLH and rCG, better human-derived gonadotrophins have also entered the market. Highly purified (HP) hMG is the latest addition to this family of infertility drugs.

The purification process of HP hMG allows its administration through the subcutaneous route with an incidence of local cutaneous reactions comparable with recombinant products. A recent large multicentre trial comparing HP hMG with rFSH{alpha} in 727 treatment cycles has shown that these two drugs appear to be equally effective when employed in assisted reproductive technology programmes (European and Israeli Study Group, 2002). However, that study did not provide information as to the exact hormone profiles resulting from the administration of HP hMG and rFSH. Furthermore, the multicentre trial format employed in this study, the use of both IVF and ICSI as assisted reproductive technology procedures, the heterogeneous pituitary suppression regimens, and the flexible gonadotrophin dosages employed limited the potential for discriminating the features of each hormone preparation examined.

Thus, we elected to plan a study with more uniform procedures in a narrowly defined patient population aiming to characterize more precisely the response to a fixed regimen of either HP hMG or rFSH{alpha} in closely monitored infertile patients undergoing assisted reproduction treatment. One critical feature of our protocol was the choice to administer a constant FSH dose (150 IU/day) for 14 consecutive days (or less if full response was achieved sooner) to all patients, without response-driven adjustments; this experimental approach was previously applied in several studies (Filicori et al., 1999bGo; 2001; European Recombinant Human LH Study Group, 1998Go). In this study we chose ICSI as the sole assisted reproductive technique as we wanted unequivocally to document oocyte maturity on the day of oocyte retrieval and to eliminate the occurrence of fertilization failures dependent on factors unrelated to the quality of the ovarian stimulation.


    Materials and methods
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
Patient population
We studied infertile subjects in good general health, and with regular menstrual cycles (25–35 days), normal body mass index (BMI) of 18–27 kg/m2, pelvic ultrasound showing a uterus and ovaries of normal size and structure (no signs of polycystic ovary syndrome), normal baseline biochemical and endocrine determinations, reproductive hormones within the normal range for the early/mid-follicular phase of the cycle, and no history or signs of endometriosis. Furthermore, none of the patients had undertaken more than three IVF or ICSI cycles in the past and all had refrained from any hormonal therapy (including gonadotrophin administration) for a period of >=3 months preceding the study.

Study design
The primary outcome measures chosen for this study were (i) the duration of gonadotrophin treatment (days) and (ii) the amount of gonadotrophin needed to achieve comparable levels of folliculogenesis. Secondary outcome measures included term pregnancy rates. The sample size (Pocock, 1983Go) was based on a previous similar trial that compared HP FSH to hMG (Filicori et al., 2001Go); according to this estimate the trial was considered large enough to provide reliable answers to the questions addressed, with 22 patients in each treatment group (t-test, based on difference between treatments of 3.5 and SD of 4). With 50 patients in each treatment group and using a significance level of 5%, the power of the study to detect a similar difference between treatments as seen in the previous trial (using a comparable assessment of variability) was estimated to be >99%. Following the CONSORT guidelines (Moher et al., 2001Go), the design and the execution of the patient randomization procedure were kept separate; the randomization sequence and the sealed envelopes containing the treatment group assignments were prepared at the University of Bologna and then sent to Farah Hospital where the patient selection and randomization process was conducted by separate personnel. A total of 150 women were screened for eligibility for the trial and 105 were found to meet the defined entry criteria and were able to receive the GnRH agonist (see below for details), but five patients failed to menstruate after GnRH agonist administration and thus could not be randomized to receive the trial medications. Therefore, 100 patients were randomized to enter the study between August 2000 and May 2001. The randomization process was conducted with sealed envelopes, containing assignment of 50 subjects to each treatment group.

Protocol
The Institutional Review Board of Farah Hospital approved the protocol and all patients provided informed consent. Following randomization, patients of groups A and B were assigned to receive rFSH{alpha} (Gonal-F; Serono Pharmaceuticals Ltd, UK), or HP hMG (Menopur; Ferring Pharmaceuticals A/S, Denmark) respectively. Although the patients and physicians were aware of the treatment allocation, the ultrasound personnel and the laboratory performing hormone assays were blind. Therapy was started in the mid-luteal phase of a spontaneous menstrual cycle with the administration of a single injection of 3.75 mg of depot triptorelin (Decapeptyl LP; IPSEN Biotech, Paris, France). Ovarian stimulation began 14 days thereafter. The gonadotrophin regimens adopted in each group were for group A rFSH{alpha} 150 IU s.c. daily, and for group B HP hMG 150 IU s.c. daily; the gonadotrophins were administered at 17:00–19:00 by a physician or a nurse, once the results of the daily estradiol (E2) assays were known. This gonadotrophin dose was continued until the occurrence of at least three ovarian follicles >=18 mm diameter and of serum E2 concentrations >600 pg/ml (final maturation parameters) or for 14 days if the final maturation parameters were not achieved. After the 14th day of treatment, increments of the gonadotrophin dose were allowed (225 IU/day on days 15–17 and 300 IU/day on days 18–20). When the final maturation parameters were attained, 10 000 IU of hCG (Profasi; Serono Pharmaceuticals Ltd) were administered to trigger final follicular maturation; the oocyte retrieval procedure was performed 35 h later and followed by a standard ICSI technique. No more than two of the embryos obtained were transferred 2 days after ICSI. Spare embryos were frozen and their outcome is not discussed further. The luteal phase was supported with 400 mg twice daily of intravaginal progesterone (Cyclogest; AH Cox & Co. Ltd., Barnstaple, UK) administered on days 3–14 following hCG.

Monitoring
Treatment monitoring was conducted throughout gonadotrophin administration. Each day, one blood sample was drawn at 08:00–09:00 in a standard manner, and two serum aliquots were obtained: E2 was measured daily in one for clinical monitoring while the second was stored at –20°C for later measurements of LH, FSH, hCG, E2, progesterone and testosterone. Transvaginal pelvic ultrasound was performed on gonadotrophin treatment days 0 and 6 and at alternate days thereafter, until pre-ovulatory hCG administration.

Hormone assays
Frozen serum samples were shipped to the University of Bologna where the hormone assays were performed. LH, FSH, E2, progesterone, testosterone, and hCG were measured with chemiluminescence assays (Chiron Diagnostics ACS 180, Italy). The minimal detectable level (MDL) of LH was 0.1 IU/l; the inter-assay coefficients of variation (CV) at low, intermediate, and high levels of the standard curve were 4.9, 6.3 and 5.5% respectively. The in-vitro addition of up to 200 000 IU/l of hCG did not affect LH determinations in this assay, as assessed at multiple levels of the standard curve. The MDL of FSH was 0.3 IU/l; the interassay CV at low, intermediate and high levels of the standard curve were 2.7, 5.0 and 3.2% respectively. The MDL of hCG in this {beta}-specific assay was 0.1 IU/l; the inter-assay CV at low, intermediate and high levels of the standard curve were 3.4, 4.5 and 5.1% respectively. The in-vitro addition of up to 200 IU/l of LH did not affect hCG determinations in this assay, as assessed at multiple levels of the standard curve. The MDL of E2 was 10 pg/ml; the interassay CV at low, intermediate and high levels of the standard curve were 5.7, 3.3 and 6.6% respectively. The MDL of progesterone was 0.1 ng/ml; the interassay CV at low, intermediate and high levels of the standard curve were 4.7, 2.3 and 4.1% respectively. The MDL of testosterone was 0.1 ng/ml; the interassay CV at low, intermediate and high levels of the standard curve were 3.5, 2.8 and 3.4% respectively.

Statistical evaluation
Data were expressed as mean ± SEM. Serum hormone levels were calculated in each cycle as area under the curve (AUC). Normality of distribution of continuous variables was assessed with a Kolmogorov–Smirnov test (with Lilliefors’ correction). Between-group differences of normally distributed continuous variables were assessed with parametric statistics (Student’s t-test), while non-parametric statistics (Mann–Whitney rank sum test) were employed when the normality test was not passed. Between-group differences in non-continuous variables were assessed with the {chi}2 method with Yates’ correction, if needed.


    Results
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
The baseline patient characteristics of the two treatment groups are shown in Table I. Except for a small difference in height, no significant between-group differences were seen in the other parameters, including weight, BMI and reproductive hormone levels.


View this table:
[in this window]
[in a new window]
 
Table I. Baseline characteristics of the patients randomized to be treated with rFSH{alpha} (group A) or highly purified (HP) hMG (group B)
 
Serum levels of reproductive hormones are shown in Table II and in Figures 1 and 2. Serum E2 concentrations were significantly higher in group B, both in the single sample drawn on the day of hCG administration and for the AUC values assessed across treatment. Serum immunoreactive FSH and hCG values across treatment were also significantly higher in group B. Finally, no significant difference existed in the other reproductive hormone concentrations during gonadotrophin treatment, including progesterone on the hCG administration day.


View this table:
[in this window]
[in a new window]
 
Table II. Serum hormone levels during treatment in patients receiving rFSH{alpha} (group A) or highly purified (HP) hMG (group B)
 


View larger version (19K):
[in this window]
[in a new window]
 
Figure 1. Gonadotrophin concentrations during the administration of 150 IU/day of rFSH{alpha} (group A) or 150 IU/day of highly purified (HP) hMG (group B). Values are mean ± SEM.

 


View larger version (20K):
[in this window]
[in a new window]
 
Figure 2. Gonadal steroid concentrations during the administration of 150 IU/day of rFSH{alpha} (group A) or 150 IU/day of highly purified (HP) hMG (group B). Values are mean ± SEM. T = testosterone; P = progesterone; E2 = estradiol.

 
Treatment outcome parameters are summarized in Table III. Among the 100 patients initially recruited, 13 did not reach the oocyte retrieval procedure (seven in group A and six in group B, P = not significant) because they failed to achieve the final maturation parameters by treatment day 20, and four did not achieve embryo transfer (three in group A and 1 in group B, P = not significant). Treatment duration (12.9 ± 0.5 versus 11.0 ± 0.4 days, P < 0.01) and gonadotrophin dose (27.0 ± 1.5 versus 22.4 ± 1.0 ampoules, P < 0.01) were significantly reduced among the HP hMG-treated patients (Figure 3). No significant between-group difference was found in the occurrence of pre-ovulatory large follicle number, the number and quality of oocytes retrieved, fertilization rates, embryos transferred, incidence of complications, pregnancy and delivery rates. A total of 23 normal term gestations (already delivered) were obtained in this study (11 in group A and 12 in group B, P = not significant).


View this table:
[in this window]
[in a new window]
 
Table III. Clinical outcome of treatment in patients treated with rFSH{alpha} (group A) or highly purified (HP) hMG (group B)
 


View larger version (15K):
[in this window]
[in a new window]
 
Figure 3. Duration of treatment (upper panel) and total gonadotrophin dose (lower panel) needed to achieve comparable levels of folliculogenesis in patients treated with rFSH{alpha} or HP hMG. *P < 0.01. Values are mean ± SEM.

 

    Discussion
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
In this study we found that both the duration of treatment and the amounts of exogenous gonadotrophins needed to achieve comparable levels of folliculogenesis were significantly reduced among patients treated with HP hMG (Figure 3). This indicates that HP hMG stimulated folliculogenesis more efficiently than rFSH{alpha}, when the same amounts of exogenous FSH were administered. This characteristic of HP hMG is likely to be related to its LH activity contents which synergizes with FSH once larger ovarian follicles begin to express granulosa cell LH receptors (Zeleznik et al., 1984Go; Filicori et al., 2002aGo). Most previous studies comparing FSH-only gonadotrophin preparations with menotropins (providing both FSH and LH activity) failed to uncover significant differences in treatment duration or gonadotrophin dose requirements (Scoccia et al., 1987Go; Bentick et al., 1988Go; Lavy et al., 1988Go; Edelstein et al., 1990Go; Fried et al., 1996Go; Ng et al., 2001Go). This apparent contradiction could partly be explained by the fact that several of these comparison studies (Daya et al., 1995Go; Imthurn et al., 1996Go; Strehler et al., 2001Go) employed a short (flare-up) GnRH agonist regimen that is associated with markedly elevated follicular phase LH concentrations (Filicori et al., 1996Go); the contribution of endogenous LH levels probably eliminated any potential difference in treatment outcome related to the LH activity content of hMG. More importantly, in all of these studies gonadotrophin dose adjustments had been allowed (usually after treatment day 5), thus introducing a critical confounding variable that probably affected these outcome parameters. Conversely, when rFSH{alpha} was compared with hMG (Filicori et al., 2003Go), and HP FSH was compared either with hMG (Filicori et al., 2001Go) or with HP FSH combined with daily low-dose hCG (50 IU/day) (Filicori et al., 1999bGo) in protocols that employed a long GnRH agonist administration and fixed daily gonadotrophin regimens similar to that of the current investigation, a congruent pattern of significantly reduced treatment duration and gonadotrophin dose was found. This finding indicates that specific features of these preparations must be assessed in a carefully controlled manner to fully uncover their potentials.

Serum levels of hCG across treatment were moderately but significantly elevated among patients treated with HP hMG (Figure 1 and Table II). Conversely, serum LH levels (Figure 1 and Table II) were largely congruent in patients treated with HP hMG or rFSH{alpha}. These findings partly contrast with the results of other studies where hMG was compared with HP FSH (Filicori et al., 2001Go) or rFSH{alpha} (Filicori et al., 2003Go) following similar drug regimens, as in these studies both daily LH and hCG serum levels were significantly increased in hMG-treated patients. Thus we confirmed that menotropin administration results in measurable hCG amounts in peripheral circulation (Filicori et al., 2001Go; 2002a) and that this hormone is a critical contributor to the overall LH activity of these products.

A somewhat unexpected feature of the current investigation was the finding of significantly higher serum levels of immunoreactive FSH in the patients treated with HP hMG than in those receiving rFSH{alpha} (Figure 1 and Table II), despite the daily administration of nominally equal amounts of FSH (150 IU/day). Baseline (day 0) values of FSH did not differ in the two treatment groups (Figure 1), thus indicating that this difference was not due to an unbalanced contribution of endogenously secreted FSH. This finding also confirmed the results of a different study where rFSH{alpha} and hMG were compared (Filicori et al., 2003Go); conversely, in a study where the same amounts of human-derived FSH and hMG were administered (150 IU/day) serum FSH concentrations overlapped (Filicori et al., 2001Go). Thus, it appears that a difference exists either in the amounts or in the pharmacokinetics of immunoreactive FSH contained in menotropins and rFSH{alpha}. Recombinant FSH preparations contain less acidic FSH isoforms than human-derived FSH that are cleared more rapidly from the peripheral circulation, possibly due to variations in sialic acid or sulphate incorporation (Mannaerts et al., 1996Go; D’Antonio et al., 1999Go). Thus, as previously reported (Matikainen et al., 1994Go; Mannaerts et al., 1996Go), single or repeated administration of rFSH gives significantly lower immunoreactive serum FSH concentrations than the administration of the same human-derived FSH amounts, consistent with the findings of our study.

The finding of significantly higher E2 levels in patients treated with HP hMG (Figure 2 and Table II) seems to confirm indirectly that this preparation contains greater amounts of LH activity. However, the increment in serum E2 could be due to: (i) an increase in the androgen substrate produced by LH activity-stimulated theca cells (which nevertheless could not be detected through peripheral serum measurements of testosterone; Figure 2 and Table II); (ii) to the direct actions of LH activity on the granulosa cell aromatase system of larger follicles that became responsive to LH through the acquisition of specific receptors (Sullivan et al., 1999Go); (iii) better stimulation of the aromatase system by the increased immunoreactive FSH concentrations found in the HP hMG group; or through a combination of these factors. Our study confirmed a similar increment in E2 levels that was previously detected when hMG and HP FSH were compared (Fried et al., 1996Go; Filicori et al., 2001Go) and the findings of the recently published multicentre trial comparing HP hMG to rFSH{alpha} (European and Israeli Study Group, 2002).

When we analysed the specific features of the ICSI procedure, we could not identify any significant difference in the number and quality of the retrieved oocytes, oocyte maturity, fertilization and pregnancy rates, and pregnancy outcome between patients treated with HP hMG or rFSH{alpha}. These results again confirm the findings of the only previous investigation that compared HP hMG with rFSH{alpha} in assisted reproductive treatment (European and Israeli Study Group, 2002Go) and of other studies where the effects of FSH-only preparations were assessed against LH activity-containing menotropins (Edelstein et al., 1990Go; Daya et al., 1995Go; Teissier et al., 1999Go; Ng et al., 2001Go; Strehler et al., 2001Go).

In conclusion, we compared HP hMG to rFSH{alpha} for ICSI in a prospective, randomized, controlled trial. We found that COS was shortened and that the drug dose needed to achieve comparable levels of folliculogenesis was reduced in HP hMG-treated patients. Administration of HP hMG also resulted in higher serum levels of LH activity, immunoreactive FSH, and E2 during COS than in rFSH{alpha}-treated patients. These features render the use of HP hMG a valuable option for ovulation induction in assisted reproduction programmes.


    Acknowledgements
 
This study was supported in part by a grant from Ferring Pharmaceuticals A/S, Copenhagen. We wish to thank Dr M.Capelli for his advice and support in the performance of laboratory hormone assay procedures, Dr A.A.Samen and Mr L.Zannarini for outstanding technical assistance, and Mr P.Sørensen of Ferring Pharmaceuticals for assistance on trial methodology.


    References
 Top
 Abstract
 Introduction
 Materials and methods
 Results
 Discussion
 References
 
Bentick, B., Shaw, R.W., Iffland, C.A., Burford, G. and Bernard, A. (1988) A randomized comparative study of purified follicle stimulating hormone and human menopausal gonadotropin after pituitary desensitization with Buserelin for superovulation and in vitro fertilization. Fertil. Steril., 50, 79–84.[ISI][Medline]

D’Antonio, M., Borrelli, F., Datola, A., Bucci, R., Mascia, M., Polletta, P., Piscitelli, D. and Papoian, R. (1999) Biological characterization of recombinant human follicle stimulating hormone isoforms. Hum. Reprod., 14, 1160–1167.[Abstract/Free Full Text]

Daya, S., Gunby, J., Hughes, E.G., Collins, J.A. and Sagle, M.A. (1995) Randomized controlled trial of follicle stimulating hormone versus human menopausal gonadotrophin in in-vitro fertilization. Hum. Reprod., 10, 1392–1396.[Abstract]

Edelstein, M.C., Brzyski, R.G., Jones, G.S., Simonetti, S. and Muasher, S.J. (1990) Equivalency of human menopausal gonadotropin and follicle-stimulating hormone stimulation after gonadotropin-releasing hormone agonist suppression. Fertil. Steril., 53, 103–106.[ISI][Medline]

European and Israeli Study Group on Highly Purified Menotropin versus Recombinant Follicle-Stimulating Hormone (2002) Efficacy and safety of highly purified menotropin versus recombinant follicle-stimulating hormone in in vitro fertilization/intracytoplasmic sperm injection cycles: a randomized, comparative trial. Fertil. Steril., 78, 520–528.[CrossRef][ISI][Medline]

European Recombinant Human LH Study Group (1998) Recombinant human luteinizing hormone (LH) to support recombinant human follicle-stimulating hormone (FSH)-induced follicular development in LH- and FSH-deficient anovulatory women: a dose-finding study. J. Clin. Endocrinol. Metab., 83, 1507–1514.[Abstract/Free Full Text]

Filicori, M., Flamigni, C., Cognigni, G.E., Falbo, A., Arnone, R., Capelli, M., Pavani, A., Mandini, M., Calderoni, P. and Brondelli, L. (1996) Different gonadotropin and leuprorelin ovulation induction regimens markedly affect follicular fluid hormone levels and folliculogenesis. Fertil. Steril., 65, 387–393.[ISI][Medline]

Filicori, M., Cognigni, G.E., Taraborrelli, S., Spettoli, D., Ciampaglia, W. and Tabarelli De Fatis, C. (1999a) Low-dose human chorionic gonadotropin therapy can improve sensitivity to exogenous follicle-stimulating hormone in patients with secondary amenorrhea. Fertil. Steril., 72, 1118–1120.[CrossRef][ISI][Medline]

Filicori, M., Cognigni, G.E., Taraborrelli, S., Spettoli, D., Ciampaglia, W., Tabarelli De Fatis, C. and Pocognoli, P. (1999b) Luteinizing hormone activity supplementation enhances follicle-stimulating hormone efficacy and improves ovulation induction outcome. J. Clin. Endocrinol. Metab., 84, 2659–2663.[Abstract/Free Full Text]

Filicori, M., Cognigni, G.E., Taraborrelli, S., Spettoli, D., Ciampaglia, W., Tabarelli De Fatis, C., Pocognoli, P., Cantelli, B. and Boschi, S. (2001) Luteinizing hormone activity in menotropins optimizes folliculogenesis and treatment in controlled ovarian stimulation. J. Clin. Endocrinol. Metab., 86, 337–343.[Abstract/Free Full Text]

Filicori, M., Cognigni, G.E., Samara, A., Melappioni, S., Perri, T., Cantelli, B., Parmegiani, L., Pelusi, G. and DeAloysio, D. (2002a) The use of LH activity to drive folliculogenesis: exploring uncharted territories in ovulation induction. Hum. Reprod. Update, 8, 543–557.[Abstract/Free Full Text]

Filicori, M., Cognigni, G.E., Tabarelli, C., Pocognoli, P., Taraborrelli, S., Spettoli, D. and Ciampaglia, W. (2002b) Stimulation and growth of antral ovarian follicles by selective LH activity administration in women. J. Clin. Endocrinol. Metab., 87, 1156–1161.[Abstract/Free Full Text]

Filicori, M., Cognigni, G.E., Taraborrelli, S., Parmegiani, L., Bernardi, S. and Ciampaglia, W. (2002c) Intracytoplasmic sperm injection pregnancy after low-dose human chorionic gonadotropin alone to support ovarian folliculogenesis. Fertil. Steril., 78, 414–416.[CrossRef][ISI][Medline]

Filicori, M., Cognigni, G.E., Pocognoli, P., Tabarelli, C., Ferlini, F., Perri, T., Parmegiani, L. (2003) Comparison of controlled ovarian stimulation with human menopausal gonadotropin and recombinant follicle stimulating hormone. Fertil. Steril., in press.

Fried, G., Harlin, J., Csemiczky, G. and Wramsby, H. (1996) Controlled ovarian stimulation using highly purified FSH results in a lower serum oestradiol profile in the follicular phase as compared with HMG. Hum. Reprod., 11, 474–477.[Abstract]

Imthurn, B., Macas, E., Rosselli, M. and Keller, P.J. (1996) Nuclear maturity and oocyte morphology after stimulation with highly purified follicle stimulating hormone compared to human menopausal gonadotrophin. Hum. Reprod., 11, 2387–2391.[Abstract]

Lavy, G., Pellicer, A., Diamond, M.P. and DeCherney, A.H. (1988) Ovarian stimulation for in vitro fertilization and embryo transfer, human menopausal gonadotropin versus pure human follicle stimulating hormone: a randomized prospective study. Fertil. Steril., 50, 74–78.[ISI][Medline]

Mannaerts, B.M., Rombout, F., Out, H.J. and Coelingh, B.H. (1996) Clinical profiling of recombinant follicle stimulating hormone (rFSH; Puregon): relationship between serum FSH and efficacy. Hum. Reprod. Update, 2, 153–161.[Abstract/Free Full Text]

Matikainen, T., de Leeuw, R., Mannaerts, B. and Huhtaniemi, I. (1994) Circulating bioactive and immunoreactive recombinant human follicle stimulating hormone (Org 32489) after administration to gonadotropin-deficient subjects. Fertil. Steril., 61, 62–69.[ISI][Medline]

Moher, D., Schulz, K.F. and Altman, D.G. (2001) The CONSORT statement: revised recommendations for improving the quality of reports of parallel-group randomized trials. Lancet, 357, 1191–1194.[CrossRef][ISI][Medline]

Ng, E.H., Lau, E.Y., Yeung, W.S. and Ho, P.C. (2001) HMG is as good as recombinant human FSH in terms of oocyte and embryo quality: a prospective randomized trial. Hum. Reprod., 16, 319–325.[Abstract/Free Full Text]

Pocock, S.J. (1983) Clinical Trials: A Practical Approach. Wiley, Chichester.

Scoccia, B., Blumenthal, P., Wagner, C., Prins, G., Scommegna, A. and Marut, E.L. (1987) Comparison of urinary human follicle-stimulating hormone and human menopausal gonadotropins for ovarian stimulation in an in vitro fertilization program. Fertil. Steril., 48, 446–449.[ISI][Medline]

Strehler, E., Abt, M., El Danasouri, I., De Santo, M. and Sterzik, K. (2001) Impact of recombinant follicle-stimulating hormone and human menopausal gonadotropins on in vitro fertilization outcome. Fertil. Steril., 75, 332–336.[CrossRef][ISI][Medline]

Sullivan, M.W., Stewart-Akers, A., Krasnow, J.S., Berga, S.L. and Zeleznik, A.J. (1999) Ovarian responses in women to recombinant follicle-stimulating hormone and luteinizing hormone (LH): a role for LH in the final stages of follicular maturation. J. Clin. Endocrinol. Metab., 84, 228–232.[Abstract/Free Full Text]

Teissier, M.P., Chable, H., Paulhac, S. and Aubard, Y. (1999) Recombinant human follicle stimulating hormone versus human menopausal gonadotrophin induction: effects in mature follicle endocrinology. Hum. Reprod., 14, 2236–2241.[Abstract/Free Full Text]

Zeleznik, A.J. and Hillier, S.G. (1984) The role of gonadotropins in the selection of the preovulatory follicle. Clin. Obstet. Gynecol., 27, 927–940.[ISI][Medline]

Submitted on September 5, 2002; resubmitted on January 16, 2003; accepted on February 27, 2003.