Human chorionic gonadotrophin contributes to the bioactivity of Pergonal

A Randomized Controlled Trial on the Efficacy and Safety of Low-Dose hCG in a Short Protocol with GnRH Agonist and Ovarian Stimulation with Recombinant FSH (rFSH) During the Follicular Phase in Infertile Women Undergoing ART

Τhis study aims to investigate whether the addition of low-dose hCG throughout stimulation in infertile women undergoing IVF improves IVF outcome parameters. This is a prospective, multicenter, randomized, double-blind, placebo-controlled, Phase IIIb clinical study, conducted in three university IVF units. We studied whether the addition of 100 IU hCG/day to a short GnRH agonist IVF protocol from the onset of the follicular phase (group 1, n=40) or placebo (group 2, n=41) had any impact on the number of high-quality transferred embryos at day 2 and clinical pregnancy rates. The comparison encompassed descriptive statistics, and univariate and multivariate analyses. Concerning the primary outcomes, we found no differences in both the number of high-quality embryos (≥2) at day 3 [21/40 (52.5%) vs. 14/41 (34.2%), p=0.095] and clinical pregnancy rates [10/40 (25%) vs. 10/41 (24.4%), p=0.949], respectively. Similarly, there were no differences concerning the secondary outcomes preset for this trial. According to the results of the multivariate logistic regression analysis, no significant associations were noted for primary outcomes (clinical pregnancy: adjusted OR=0.89, 95% CI: 0.29–2.75; (≥2 excellent quality embryos at day 3: adjusted OR=0.54, 95% CI: 0.21–1.42, with group 1 set as reference category); similarly, no differences were noted with respect to secondary outcomes, except from the increased odds of ≥2 poor-quality embryos at day 3 occurring in group 2 (adjusted OR= 11.69, 95%CI: 1.29–106.19). The addition of low-dose hCG to a short GnRH agonist protocol for IVF does not improve the number of top-quality embryos and clinical pregnancy rates.

A review of luteinising hormone and human chorionic gonadotropin when used in assisted reproductive technology

Gonadotropins extracted from the urine of post-menopausal women have traditionally been used to stimulate folliculogenesis in the treatment of infertility and in assisted reproductive technology (ART). Products, such as human menopausal gonadotropin (hMG), consist not only of a mixture of the hormones, follicle-stimulating hormone (FSH), luteinising hormone (LH) and human chorionic gonadotropin (hCG), but also other biologically active contaminants, such as growth factors, binding proteins and prion proteins. The actual amount of molecular LH in hMG preparations varies considerably due to the purification process, thus hCG, mimicking LH action, is added to standardise the product. However, unlike LH, hCG plays a different role during the natural human menstrual cycle. It is secreted by the embryo and placenta, and its main role is to support implantation and pregnancy. More recently, recombinant gonadotropins (r-hFSH and r-hLH) have become available for ART therapies. Recombinant LH contains only LH molecules. In the field of reproduction there has been controversy in recent years over whether r-hLH or hCG should be used for ART. This review examines the existing evidence for molecular and functional differences between LH and hCG and assesses the clinical implications of hCG-supplemented urinary therapy compared with recombinant therapies used for ART.

Exposing cultured mouse ovarian follicles under increased gonadotropin tonus to aromatizable androgens influences the steroid balance and reduces oocyte meiotic capacity

Acquisition of oocyte developmental competence relies on the well-controlled events accompanying antral follicular development. Elevated basal androgen levels, as in PCOS, potentially affect oocyte quality. Current experiments in an in vitro follicle bioassay studied dose-effects of androstenedione and testosterone on FSH and hCG stimulated antral follicle growth and meiotic maturation. The addition of either androgens altered follicle's endogenous production of androstenedione, testosterone, estradiol, and progesterone and affected the oocyte's capacity to resume meiosis. Exposure to 200 nM androstenedione induced an increased production of testosterone and estradiol. Exposure to a concentration of ≥200 nM testosterone induced elevated levels of estradiol and progesterone. Significant dose-dependent negative effects on polar body extrusion were seen at concentrations of ≥200 nM of either androgen. In addition, chromosome displacement on the metaphase plate was observed in oocytes obtained from androstenedione-treated follicles. Follicles exposed to a combination of 25 mIU/ml FSH and 3 mIU/ml hCG and elevated aromatizable androgens altered the steroid production profile, affected the follicular development and impaired oocyte meiotic competence.

Lutropin alfa

Lutropin alfa is the first and only recombinant human form of luteinizing hormone (LH) developed for use in the stimulation of follicular development. Dose-finding studies revealed a significant dose-dependent increase in the rate of optimal follicular development among women with hypogonadotropic hypogonadism and profound LH deficiency (<1.2 IU/L) who received subcutaneous lutropin alfa 0-225 IU/day plus follitropin alfa. Similarly, in a double-blind, randomized study, the rate of optimal follicular development was significantly higher in women with hypogonadotropic hypogonadism and profound LH deficiency receiving subcutaneous lutropin alfa 75 IU/day plus follitropin alfa than in those receiving placebo plus follitropin alfa. Lutropin alfa with follitropin alfa may also be of benefit in certain subgroups of normogonadotropic women (e.g. those with an inadequate response to prior follitropin alfa monotherapy, those aged >or=35 years, and those with profound LH downregulation or who required excessive exogenous follitropin alfa). However, one study in older women (>or=35 years) did not show any advantage of lutropin alfa supplementation. Once-daily subcutaneous lutropin alfa was generally well tolerated in hypogonadotropic hypogonadal women, with the majority of adverse events being of mild to moderate severity.

FSH isoform composition of commercial gonadotrophin preparations: a neglected aspect?

The clinical efficacy of commercial gonadotrophin preparations has been the subject of an intense debate during recent years. Arguments have primarily focused on the origin of FSH activity (urine versus recombinant derived) and whether the preparation included LH-like activity. FSH isoform composition has received little or no attention, and is usually considered to have negligible effect on clinical effectiveness. By presenting the available data on the FSH isoform composition of commercial gonadotrophin preparations, the present paper challenges this assumption. To evaluate whether the FSH isoform composition affected the efficacy of a product, a meta-analysis was performed that compared a preparation expressing an acidic isoform profile (urinary-derived Metrodin-HP) with a preparation rich in less acidic isoforms (recombinant derived Gonal F). A total of five randomized clinical trials that specifically compared these two preparations was identified and included in the analysis. All parameters relating to the direct effect of FSH on the follicle differed significantly in favour of the product rich in less acidic isoforms, while data on pregnancy outcome did not reach significance. The importance of the FSH isoform profile and whether the FSH is derived from urine or by recombinant technique is discussed in relation to clinical efficacy. It is suggested that the FSH isoform profile of commercial gonadotrophin preparations is of clinical importance and should be taken into account when evaluating efficacy.

Factors influencing response to ovarian stimulation

Ovarian stimulation is an integral part of assisted reproduction treatments. Ovarian response to gonadotrophin treatment, besides other factors, determines the outcome of treatment, as the number and quality of oocytes retrieved are related to the chance of achieving a pregnancy. A number of factors have been identified that might predict ovarian response, such as age of the patient and antral follicle count. In addition, it has been shown that genetic factors such as the patient's FSH-receptor genotype also determine individual response to FSH treatment. Besides patient-related factors, the choice of drugs for ovarian stimulation plays a significant role. Until recently, biopotency of gonadotrophin preparations was tested by an in-vivo bioassay with an intrinsic variability up to 20%. Due to a superior manufacturing technique, follitropin alpha can now be filled by mass. This allows assessment of FSH with a precise SE-HPLC assay and variability of the FSH content between production lots has now been estimated at 1.6%. Results of recent studies indicate that treatment with follitropin alpha filled by mass results in consistent ovarian response, fewer treatment days and fewer cancelled cycles. This is an important step towards further minimizing drug-related variability of ovarian response to FSH treatment.

LH improves early follicular recruitment in women over 38 years old

Although the capacity of recombinant FSH alone to induce folliculogenesis is undisputed, many believe that follicular recruitment in women over 38 years old could be improved by supplementing rFSH with human menopausal gonadotrophin (HMG). The present study sought to determine whether recombinant LH could reproduce the effect of HMG in women over 38 years during ovulation induction. Fifty-eight patients received rFSH (225 IU/day) supplemented with one ampoule of HMG (75 IU of FSH/75 IU of LH/HCG per day) for 5 days. Another 36 patients received rFSH (300 IU/day) supplemented with one ampoule of rLH (75 IU/day), also for 5 days. Both groups of patients received similar amounts of rFSH (1500 IU), LH/HCG (375 IU) and rLH (375 IU) and recruited a similar number of follicles as counted on day 6 (4.07 +/- 3.1 in the HMG group versus 3.7 +/- 3.2 in the LH group respectively) or on the day that human chorionic gonadotrophin (HCG) was indicated (6.5 +/- 2.7 versus 5.8 +/- 2.5 respectively). Ovarian stimulation was shorter, but not significantly so, in the group of patients receiving rFSH + HMG (10.5 +/- 1.7 days) than in the group of patients treated with rFSH +/- rLH (12 +/- 1.8 days). Significantly more MII oocytes were seen in the group treated with rFSH + rLH than in the group treated with rFSH + HMG (93.1 versus 75.3%, P < 0.05). With respect to pregnancy rates, 14/54 (26%) patients receiving rFSH + HMG and 16/34 (47%) patients receiving rFSH + rLH had a positive serum HCG. No significant difference in the number of miscarriages was observed between the two groups. In conclusion, the present results seem to indicate that rLH could be the HMG component that aids early follicular recruitment.

Current concepts and novel applications of LH activity in ovarian stimulation

Luteinizing hormone (LH) is a crucial physiological regulator of the human menstrual cycle. LH activity is also contained in many medications used to treat anovulation and to stimulate multiple folliculogenesis for assisted reproduction techniques. However, LH activity had previously been regarded as just a contaminant of follicle-stimulating hormone (FSH)-containing products and deemed potentially detrimental for reproductive function. Novel experimental and clinical evidence now suggests that the administration of pharmacological amounts of LH activity, instead of being harmful, is therapeutically advantageous, particularly in the support and modulation of ovarian folliculogenesis. The aim of this article is to provide an overview of the effects of LH activity administration in ovarian stimulation and to outline novel unconventional gonadotropin regimens that might improve the efficacy, safety and convenience of ovulation induction.

Ovulation induction with low dose alternate day recombinant follicle stimulating hormone (Puregon)

We investigated whether a recombinant follicle stimulating hormone (FSH) (Puregon) can be administered less frequently and at lower doses during ovulation induction than is current practice. Patients (20-35 years, body mass index <30 kg/m(2)) with infertility and chronic anovulation secondary to polycystic ovarian syndrome and resistant to previous clomiphene treatment received (Puregon); 100 IU, n = 17 patients, or 50 IU, n = 10 patients) on alternate days. After 2 weeks and in the absence of follicular recruitment, doses were increased stepwise at weekly intervals (50 IU/alternate days). Twenty-two cycles out of 27 were ovulatory. There were six pregnancies, five from Puregon (100 IU) and one from Puregon (50 IU); four pregnancies proceeded to term. The duration of stimulation (mean, range) with Puregon (100 IU) was 16.4, 7-29 and Puregon (50 IU) 19.1, 8-38 days. The gonadotrophin doses administered (mean; range) were 689, 200-1800 IU (Puregon 50 IU) and 939, 400-2300 IU (Puregon 100 IU). We conclude that low dose alternate day Puregon treatment is suitable for this difficult patient group.

Relationship between circulating human chorionic gonadotropin levels and premature luteinization in cycles of controlled ovarian hyperstimulation

OBJECTIVE

To determine if premature luteinization (serum P levels > 1.1 ng/mL on or before the day of hCG administration) during controlled ovarian hyperstimulation (COH) is associated with elevated levels of serum hCG.

SETTING

Tertiary fertility center.

DESIGN

Retrospective evaluation of ovum donors undergoing COH.

PATIENTS

Forty-four women underwent COH. Comparisons of serum hCG levels and hormonal and cycle characteristics were made between cycles with premature luteinization (group I) and without premature luteinization (group II).

RESULTS

Group I (16 women) were similar to women in group II in age, amount of hMG, and the ratio of FSH:hMG received. Both groups received hCG on similar days, but women in group I had higher peak E2 levels. Serum hCG levels increased and correlated with serum P levels in group I only and were higher on the day of hCG administration (group I 1.8 +/- 0.9 mIU/mL versus group II 1.2 +/- 0.45 mIU/mL; conversion factor to SI unit, 1.00). Peak E2 and LH levels, ampules of hMG and the FSH:LH ratio, and day of hCG administration did not correlate with hCG levels. Human chorionic gonadotropin exposure, as measured by area under the curve, was significantly higher in group I compared with group II.

CONCLUSION

Higher serum levels of hCG and integrated hCG exposure are found in COH cycles with premature luteinization compared with cycles without premature luteinization. Higher hCG levels may be due to decreased clearance of hCG from the circulation and/or the hCG content of hMG.

Human chorionic gonadotropin in commercial human menopausal gonadotropin preparations

Several studies indicated the presence of an hCG-immunoreactive substance in commercial hMG preparations. Because hCG represents LH activity with a relatively very long half-life, differences between hMG preparations with respect to hCG content could imply clinical differences. To investigate whether there is any difference in this respect between the two most widely used hMG preparations, we measured the hCG content of ampules of Humegon and Pergonal retrieved from the market, together representing 51 separate production batches, with one or more different specific immunological assays. There are no significant differences between Humegon and Pergonal with respect to the mean hCG level per ampule as measured by RIA, ELISA, and Delfia. The batch-to-batch consistency for Humegon is higher.