Effects of gonadotrophin-releasing hormone agonists on human ovarian steroid secretion in vivo and in vitro-results of a prospective, randomized in-vitro fertilization study

Effects of Different Exposure Days to Gonadotropin-Releasing Hormone Agonist (GnRH-a) on Live Birth Rates in the Depot GnRH-a Protocol: A Retrospective Analysis of 7007 Cycles

Background

In controlled ovarian hyperstimulation protocols worldwide, depot gonadotropin-releasing hormone agonist (GnRH-a) pretreatment is generally used for pituitary desensitization. The delay between the GnRH-a administration and starting gonadotropin treatment varies greatly, from 25 to 60 days. However, the association between exposure days to GnRH-a before the onset of gonadotropin administration and the clinical outcomes remains unknown.

Material/Methods

This retrospective study included 7007 patients who underwent fresh embryo transfers between February 2016 and July 2019. The duration of pituitary downregulation was categorized into 3 groups: group 1, ≤30 days; group 2, 31–35 days; and group 3, ≥36 days. The rates of live birth were compared as the main outcome measure. Logistic regression analysis was also performed after controlling for a range of confounders.

Results

The number of patients in groups 1, 2, and 3 was 2001, 2824, and 2182, respectively. Group 3 (≥36 days) had a noticeably higher live birth rate (48.1%) than the other 2 groups (42.6% and 43.9%, P=0.001). The rate of live birth was remarkably enhanced in group 3 (adjusted odds ratio: 1.264, 95% confidence interval: 1.098, 1.455, P=0.001) after controlling for confounders, while the difference was not found in group 2 (P=0.512) compared with group 1.

Conclusions

In the depot GnRH-a protocol, live birth rates are higher among patients needing a longer time to achieve the goal of pituitary downregulation.

Prolonged pituitary down-regulation with full-dose of gonadotropin-releasing hormone agonist in different menstrual cycles: a retrospective cohort study

Background

The efficiency of prolonged down-regulation caused by a full-dose of gonadotropin-releasing hormone agonist (GnRH-a) injected during different menstrual phases has not yet been researched. Our goal was to evaluate the effects of GnRH-a, which was used in different phases of the menstrual cycle in patients undergoing in vitro fertilization and embryo transfer.

Methods

This was a retrospective cohort study. A total of 320 patients received a prolonged pituitary down-regulated full-dose (3.75 mg) of triptorelin in the early follicular phase, and 160 patients received the same full-dose of triptorelin during the mid-luteal phase. Clinical and laboratory outcomes were compared between the two groups.

Results

The basic characteristics of the two groups were comparable. The mean number of retrieved oocytes, fertilized oocytes, cleavage oocytes and good quality embryos were comparable between the two groups. Although there was a higher antral follicle count, cyst formation rate, fertilization rate and cleavage rate in the follicular phase group, no statistically significant effects were seen on implantation rate (41.15% vs. 45.91%), clinical pregnancy rate (60.38% vs. 61.36%), ongoing pregnancy rate (57.74% vs. 57.58%), live birth rate (56.23% vs. 57.58%) or early abortion rate (2.64% vs. 3.79%) per fresh transfer cycle. Moreover, severe ovarian hyperstimulation syndrome rates at the early stage (1.89% vs. 2.27%) were low in both groups.

Conclusions

Prolonged pituitary down-regulation achieved by utilizing a full-dose of GnRH-a administrated in either phase of the menstrual cycle can have a positive effect on ongoing pregnancy rate and live-birth rate per fresh embryo transfer cycle. Ovarian cyst formation rate was higher in the follicular phase group, but this did not have any adverse impact on clinical results.

Changes in ovarian function associated with circulating concentrations of estradiol before a GnRH-induced ovulation in beef cows

These studies were conducted to evaluate causes for differences in circulating concentrations of estradiol before a GnRH-induced ovulation. Beef cows were synchronized by an injection of GnRH on day -7 and an injection of prostaglandin F2α (PGF2α) on day 0. In experiment 1, blood samples were collected every 3 h from PGF2α on day 0 to hour 33 after PGF2α and at slaughter (hour 36 to 42; n = 10). Cows were assigned to treatment group based on circulating concentrations of estradiol (E2): HighE2 vs LowE2. At slaughter, follicular fluid (FF) and granulosa cells were collected from the dominant follicle. In experiment 2, blood samples (n = 30) were collected every 8 h from PGF2α until the dominant follicle was aspirated via ultrasound-guided follicular aspiration to collect FF and granulosa cells (hour 38 to 46). In experiment 1, HighE2 had increased abundance of 3β-hydroxysteroid dehydrogenase, cytochrome P450 aromatase, and LHR (P ≤ 0.02), and greater concentrations of estradiol and androstenedione (P ≤ 0.02) in the FF. In experiment 2, HighE2 had increased abundance of CYP11A1, 3β-hydroxysteroid dehydrogenase, cytochrome P450 aromatase, and LHR (P ≤ 0.03) vs either LowE2 or GnRHLowE2. There was a tendency (P = 0.07) for LH pulse frequency to be increased in both the GnRHLowE2 and HighE2 compared with LowE2. HighE2 cows experienced increas in circulating concentrations of estradiol compared with LowE2. In conclusion, animals with greater concentrations of circulating estradiol before fixed-time AI experienced an upregulation of the steroidogenic pathway during the preovulatory period.

Does lower dose of long-acting triptorelin maintain pituitary suppression and produce good live birth rate in long down-regulation protocol for in-vitro fertilization?

The effects of pituitary suppression with one-third depot of long-acting gonadotropin-releasing hormone (GnRH) agonist in GnRH agonist long protocol for in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) were investigated. A retrospective cohort study was performed on 3186 cycles undergoing IVF/ICSI with GnRH agonist long protocol in a university-affiliated infertility center. The pituitary was suppressed with depot triptorelin of 1.25 mg or 1.875 mg. There was no significant difference in live birth rate between 1.25 mg triptorelin group and 1.875 mg triptorelin group (41.2% vs. 43.7%). The mean luteinizing hormone (LH) level on follicle-stimulating hormone (FSH) starting day was significantly higher in 1.25 mg triptorelin group. The mean LH level on the day of human chorionic gonadotrophin (hCG) administration was slightly but statistically higher in 1.25 mg triptorelin group. There was no significant difference in the total FSH dose between the two groups. The number of retrieved oocytes was slightly but statistically less in 1.25 mg triptorelin group than in 1.875 mg triptorelin group (12.90±5.82 vs. 13.52±6.97). There was no significant difference in clinical pregnancy rate between the two groups (50.5% vs. 54.5%). It was suggested that one-third depot triptorelin can achieve satisfactory pituitary suppression and produce good live birth rates in a long protocol for IVF/ICSI.

Direct ovarian effects and safety aspects of GnRH agonists and antagonists

The wide application of gonadotrophin-releasing hormone (GnRH) analogues in assisted reproduction has raised concerns about their potential extra-pituitary actions. Although data from animal studies support the presence of ovarian GnRH receptors and of direct ovarian effects of GnRH analogues, this has not been unequivocally demonstrated in humans. Available evidence suggests, however, the existence of GnRH receptors in human granulosa-luteal cells, while the majority of the studies performed showed that progesterone is inhibited by GnRH agonists in vitro. On the other hand, no difference seems to exist between agonists and antagonists in terms of granulosa-luteal cell steroidogenesis under basal conditions. So far, no studies have suggested an adverse effect of GnRH analogues on the developing human follicle. Moreover, the physiological significance of a direct in-vitro ovarian effect of GnRH analogues remains to be established.

Depot versus daily administration of gonadotrophin-releasing hormone agonist protocols for pituitary down regulation in assisted reproduction cycles

BACKGROUND

Gonadotrophin-releasing hormone agonist (GnRHa) is commonly used to switch off (down regulate) the pituitary gland and thus suppress ovarian activity in women undergoing in vitro fertilisation (IVF). Other fertility drugs (gonadotrophins) are then used to stimulate ovulation in a controlled manner. Among the various types of pituitary down regulation protocols in use, the long protocol achieves the best clinical pregnancy rate. The long protocol requires GnRHa administration until suppression of ovarian activity occurs, within approximately 14 days. GnRHa can be used either as daily low-dose injections or through a single injection containing higher doses of the drug (depot). It is unclear which of these two forms of administration is best, and whether single depot administration may require higher doses of gonadotrophins.

OBJECTIVES

To compare the effectiveness and safety of a single depot dose of GHRHa versus daily GnRHa doses in women undergoing IVF.

SEARCH METHODS

We searched the following databases: Cochrane Menstrual Disorders and Subfertility Group Trials Register (searched July 2012), Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library 2012, Issue 7), MEDLINE (1966 to July 2012), EMBASE (1980 to July 2012) and LILACS (1982 to July 2012). We also screened the reference lists of articles.

SELECTION CRITERIA

We included RCTs comparing depot and daily administration of GnRHa for long protocols in IVF treatment cycles in couples with any cause of infertility, using various methods of ovarian stimulation. The primary review outcomes were live birth or ongoing pregnancy, clinical pregnancy and ovarian hyperstimulation syndrome (OHSS). Other outcomes included number of oocytes retrieved, miscarriage, multiple pregnancy, number of gonadotrophin (FSH) units used for ovarian stimulation, duration of gonadotrophin treatment, cost and patient convenience.

DATA COLLECTION AND ANALYSIS

Two review authors independently selected studies, extracted data and assessed study quality. For dichotomous outcomes, we calculated odds ratios (ORs) and 95% confidence intervals (CIs) per woman randomised. Where appropriate, we pooled studies.

MAIN RESULTS

Sixteen studies were eligible for inclusion (n = 1811 participants), 12 (n = 1366 participants) of which were suitable for meta-analysis. No significant heterogeneity was detected.There were no significant differences between depot GnRHa and daily GnRHa in live birth/ongoing pregnancy rates (OR 0.95, 95% CI 0.70 to 1.31, seven studies, 873 women), but substantial differences could not be ruled out. Thus for a woman with a 24% chance of achieving a live birth or ongoing pregnancy using daily GnRHa injections, the corresponding chance using GnRHa depot would be between 18% and 29%.There was no significant difference between the groups in clinical pregnancy rate (OR 0.96, 95% CI 0.75 to 1.23, 11 studies, 1259 women). For a woman with a 30% chance of achieving clinical pregnancy using daily GnRHa injections, the corresponding chance using GnRHa depot would be between 25% and 35%.There was no significant difference between the groups in the rate of severe OHSS (OR 0.84, 95% CI 0.29 to 2.42, five studies, 570 women), but substantial differences could not be ruled out. For a woman with a 3% chance of severe OHSS using daily GnRHa injections, the corresponding risk using GnRHa depot would be between 1% and 6%.Compared to women using daily GnRHa, those on depot administration required significantly more gonadotrophin units for ovarian stimulation (standardised mean difference (SMD) 0.26, 95% CI 0.08 to 0.43, 11 studies, 1143 women) and a significantly longer duration of gonadotrophin use (mean difference (MD) 0.65, 95% CI 0.46 to 0.84, 10 studies, 1033 women).Study quality was unclear due to poor reporting. Only four studies reported live births as an outcome and only five described adequate methods for concealment of allocation.

AUTHORS' CONCLUSIONS

We found no evidence of a significant difference between depot and daily GnRHa use for pituitary down regulation in IVF cycles using the long protocol, but substantial differences could not be ruled out. Since depot GnRHa requires more gonadotrophins and a longer duration of use, it may increase the overall costs of IVF treatment.

Endometriosis does not Alter Aromatase Gene Expression (CYP19A1) in Mural Lutein-granulosa Cells of Women Undergoing Assisted Reproduction Techniques – a Pilot Study

Purpose

The aim of this study was to quantify aromatase gene expression in mural lutein-granulosa cells of women with endometriosis undergoing assisted reproduction techniques (ART, IVF or ICSI). Methods: a case-control study was performed on 11 women with endometriosis (all stages, ASRM criteria) and 11 women with male or tubal causes of infertility undergoing ART. There was no difference between the groups regarding age, amount of gonadotrophins used, days of induction, follicles, and eggs collected. Mural lutein-granulosa cells were harvested from pre-ovulatory follicles during oocyte retrieval and correctly isolated. After cells lyses and storage into Trizol LS Reagent®, RNA extraction and cDNA synthesis were performed. Quantification of relative gene expression for CYP19A1 (aromatase) was performed by real time PCR, using SYBR Green reagents. All experiments were performed in duplicates.

Results

there was no difference between the groups in the quantitative gene expression of CYP19A1 (aromatase) gene on mural lutein-granulosa cells (P>.05, Mann Whitney).

Conclusions

These results suggest that this enzyme, aromatase, may have a complex and refined control of its gene expression on this population of granulosa cells, and in spite of previous evidence showing its reduced activity on these cells in endometriosis, gene expression per se may not be affected by the disease.

Follicular growth and oocyte maturation in GnRH agonist and antagonist protocols for in vitro fertilisation and embryo transfer

BACKGROUND

The aim of this study was to evaluate the response to treatment in a group of patients undergoing IVF and randomised to receive GnRH-antagonist or the GnRH-agonist. The endpoints were the pattern of follicular growth, the maturity of the oocytes collected, the embryo quality and the pregnancy outcome.

METHODS

A total of 136 patients undergoing IVF were included. Sixty-seven patients were allocated to the GnRH antagonist and 69 patients to the GnRH agonist. GnRH antagonist was administered when the leading follicle reached a diameter of 12-14 mm. GnRH agonist was administered in a long luteal protocol.

RESULTS

The mean numbers of oocytes retrieved and mature oocytes were significantly higher in the agonist than in the antagonist group (p < 0.02 and p < 0.01, respectively). Embryo quality, implantation rate, clinical pregnancy rates, ongoing pregnancy rate and miscarriage rate were similar in both groups.

CONCLUSIONS

Better follicular growth and oocyte maturation are achieved with GnRH agonist treatment. However, both regimens seem to have similar efficacy in terms of implantation and pregnancy rates. Further studies clarifying the effect of the GnRH antagonist on ovarian function are needed, as well as a clear definition of the best period of the follicular phase for the GnRH antagonist administration.

Androgen deficiency: effects on body composition

Published data on the effects of androgen deficiency and testosterone administration on body composition in men and women are reviewed. In experimental paradigms, androgen deprivation decreases lean body mass and increases fat mass in men, and physiologic replacement reverses these abnormalities. The anabolic effects of testosterone administration on muscle in men are well-established, and current understanding of the underlying mechanisms are discussed. Randomized, placebo-controlled studies have been performed to investigate the effects of testosterone administration on body composition in a number of male hypogonadal states, including HIV-associated weight loss, supraphysiologic glucocorticoid administration, aging and obesity, with variable outcomes, and the results are reviewed. There are few data investigating the effects of hypoandrogenemia or androgen replacement on body composition in women, in whom endogenous testosterone levels are a fraction of those in men. A recent randomized, placebo-controlled study of physiologic testosterone replacement therapy in women with profound hypoandrogenemia due to hypopituitarism demonstrated an increase in skeletal muscle mass but no change in body fat. Further research is needed to establish the effects of endogenous androgens on the regulation of body composition in women.

Leuprolide acetate reduces both in vivo and in vitro ovarian steroidogenesis in infertile women undergoing assisted reproduction

Despite the probable inhibitory effects of GnRH analogues on ovarian steroidogenesis in vitro, their association with assisted reproduction protocols shows favorable results. This suggests that there are important differences in the behaviors of these drugs when administered in vivo versus in vitro. To clarify these differences, this study was designed to analyze the effect of leuprolide acetate (LA) on ovarian steroidogenesis in women undergoing In Vitro Fertilization (IVF). A prospective, randomized open label study was conducted on 14 women (26-35 years): seven receiving only gonadotrophins (Group 1) and seven receiving gonadotrophin plus LA at 1mg/day (Group 2). The LA in vivo effect was determined with serum and follicular fluid (FF) samples and via luteinized granulosa cell cultivation (GCC), where cells were obtained during oocyte retrieval after ovarian hyperstimulation. In vitro analysis was performed via addition of LA to GCC only for Group 1 (without LA) at progressively higher concentrations (0, 10(-12), 10(-9) and 10(-6)M). In vivo, the main observation was a reduction in androgen production in Group 2, represented by lower androstenedione production in FF (G1=6479+/-3458; G2=3021+/-1119 ng/ml; p=0.04) and a lower testosterone peak in GC at 96h (G1=0.64+/-0.12 ng/ml; G2=0.50+/-0.19 ng/ml; P=0.02), but a higher fertilization rate (G1=67%; G2=83%; p=0.009). In vitro, testosterone, estradiol and progesterone were also reduced by LA, even though this reduction occurred for progesterone only at the highest LA dosage (10(-6)M; 606.0+/-114.3 ng/ml versus 1524.0+/-246.5 ng/ml; p=0.02). Results show that LA reduces ovarian steroidogenesis in vivo by essentially inhibiting androgen synthesis; whereas, in vitro, ovarian steroidogenesis is reduced overall.

Effects of gonadotropin-releasing hormone agonist/recombinant follicle-stimulating hormone versus gonadotropin-releasing hormone antagonist/recombinant follicle-stimulating hormone on follicular fluid levels of adhesion molecules during in vitro fertilization

OBJECTIVE

To compare the effects of GnRH-agonist/recombinant rFSH versus GnRH-antagonist/recombinant FSH stimulation on follicular fluid levels of soluble intercellular adhesion molecule (sICAM)-1 and vascular cell adhesion molecule-1 (sVCAM-1) during in vitro fertilization (IVF).

DESIGN

Prospective, randomized study.

SETTING

University hospital.

PATIENT(S)

Seventy-three women underwent IVF.

INTERVENTION(S)

GnRH-agonist/rFSH or GnRH-antagonist/rFSH administration and collection of follicular fluid from 3 small (11-14 mm in diameter) and 3 large (18-21 mm in diameter) follicles on the day of oocyte retrieval.

MAIN OUTCOME MEASURE(S)

Follicular fluid levels of sICAM-1 and sVCAM-1 and intrafollicular estradiol and progesterone were also measured.

RESULT(S)

Women who underwent GnRH-agonist/rFSH showed higher concentrations of sICAM-1 in both small and large follicles were compared with patients who received GnRH-antagonist/rFSH treatment; follicular fluid levels of sVCAM-1 were similar between the 2 stimulation protocols. Content of sICAM-1 in small and large follicles positively correlated with the number of follicles of > or =15 mm and the number of oocytes that were retrieved in both study groups. Concentrations of follicular fluid sVCAM-1 and progesterone were higher in large than in small follicles and were correlated positively to each other in both follicular classes.

CONCLUSION(S)

In IVF, GnRH-agonist/rFSH is associated with higher follicular fluid levels of sICAM-1 compared with GnRH-antagonist/rFSH regimen. Intrafollicular sICAM-1 content may predict ovarian response, and sVCAM-1 appears as an indicator of the degree of follicular luteinization.

Comparisons of follicular levels of sex steroids, gonadotropins and insulin like growth factor-1 (IGF-1) and epidermal growth factor (EGF) in poor responder and normoresponder patients undergoing ovarian stimulation with GnRH antagonist

OBJECTIVE

To determine the serum and intrafollicular concentrations of sex steroids, epidermal growth factor (EGF) and insulin like growth factor-1 (IGF-1) in women demonstrating poor response to ovarian stimulation with gonadotropins and GnRH antagonists, and to compare the results with age-matched women displaying normal ovarian response.

STUDY DESIGN

This is a prospective cross-sectional study conducted in a private IVF center. Forty-eight age-matched women producing 5 or fewer oocytes (poor responders) or 10 or more oocytes (normoresponders) at the end of controlled ovarian stimulation for assisted conception participated in the experiment. Gonadotropins and GnRH antagonists were used for ovarian stimulation, while ICSI was employed for assisted fertilization. Serum and follicular concentrations of FSH, LH and sex steroids (estradiol, progesterone and testosterone), and follicular concentrations of EGF and IGF-1 were assayed in both groups.

RESULTS

Serum and follicular levels of E(2) and progesterone were significantly lower in the poor responder group compared to the normoresponder group. Follicular level of testosterone was also lower in poor responders, but not to a level of statistical significance. The serum FSH level was higher in the poor responder group, but follicular levels of gonadotropins did not differ between the two groups. The follicular level of IGF-1 was significantly lower in poor responders. In contrast, the EGF concentration did not differ between the two groups.

CONCLUSIONS

Decreased levels of sex steroids in poor responder patients undergoing COH with GnRH antagonist, suggests that reduced IGF-1 expression acts as a modulator of impaired ovarian steroidogenesis.

Triggering ovulation with gonadotropin-releasing hormone agonists does not compromise embryo implantation rates

OBJECTIVE

To evaluate the implant capacity of embryos derived from oocytes matured with a bolus of GnRH agonist.

DESIGN

Donors were randomly assigned to a protocol using either GnRH agonist or recombinant (r) hCG to trigger ovulation. Analysis of variance, Student t test, and Fisher exact test were used where appropriate.

SETTING

Private clinical setting.

PATIENT(S)

Young voluntary donors receiving GnRH agonist (n = 30) or rhCG (n = 30). Eighty-nine patients received oocytes.

INTERVENTION(S)

Controlled ovarian stimulation was carried out with GnRH antagonist and FSH/LH in a step-down protocol. Donors received a single bolus of GnRH agonist (0.2 mg) or rhCG (250 microg). The endometrial tissue of recipient patients was prepared with oral E(2) and P.

MAIN OUTCOME MEASURE(S)

Pregnancy and implantation rates and ovarian hyperstimulation syndrome (OHSS) in an IVF donor program.

RESULT(S)

No significant differences in the number of retrieved oocytes (327 vs. 288), MII oocytes (70% vs. 76%), fertilization (80% vs. 65%,), pregnancy/transfer (55% vs. 59%), and implantation rates (29% vs. 32%) were found between recipients whose embryos originated from donors in whom final oocyte maturation was triggered with GnRH agonist and those whose donors received hCG. Significant differences in luteal phase length (4.16 + 0.70 days vs. 13.63 + 2.12 days) and in OHSS (0/30 vs. 5/30) were seen between donors ovulated with the agonist and the donors in whom ovulation was triggered with hCG.

CONCLUSION(S)

In controlled ovarian stimulation IVF donor cycles, GnRH agonists trigger ovulation and induce luteolysis but do not compromise embryo implantation capacity.

GnRH agonist Lupron® (leuprolide acetate) pre-treatments prevent ovulation in response to gonadotropin stimulation in the clouded leopard (Neofelis nebulosa)

In many species, controlling the ovary prior to induction of ovulation improves the success of ovarian response and artificial insemination (AI). We assessed the impact of suppression of estrus with the GnRH agonist, Lupron, on ovarian sensitivity to equine chorionic gonadotropin (eCG) and human chorionic gonadotropin (hCG) in the clouded leopard. Seven female clouded leopards were given two injections of Lupron (3.75 mg IM) 23 d apart, followed 44 d later by eCG and hCG. Daily fecal samples were collected from 60 d before Lupron to 60 d after hCG. Fecal metabolites of estrogen (E) and progesterone (P) were measured by radioimmunoassay. Lupron decreased (P < 0.05) the number of E peaks during Lupron treatment compared to pre-Lupron. All females had baseline E and six of seven (86%) had nadir P on day of eCG. Exogenous gonadotropins induced E elevations in all females. However, mean E in the gonadotropin-provoked estrus was decreased (P < 0.05) compared to pre-Lupron estrous periods. Only one of seven (14%) females ovulated after eCG/hCG. In conclusion, estrous cycle control with Lupron resulted in predictable ovarian suppression prior to gonadotropin stimulation but altered ovarian sensitivity by an as yet unknown mechanism so that ovulation was inhibited, even when using a proven exogenous gonadotropin protocol.

Safety and efficacy of low dose hCG for luteal support after triggering ovulation with a GnRH agonist in cases of polyfollicular development

OBJECTIVE

The use of GnRH agonists instead of hCG to trigger ovulation seems to be an effective way to prevent subsequent hCG induced ovarian hyperstimulation in cases of polyfollicular development. But conflicting results are reported on the efficiency of subsequent luteal support using hCG and/or progesterone supplementation.

STUDY DESIGN

We investigated the efficiency and safety of different luteal support regimes in low dose gonadotropin stimulation non-ivf cycles. A risk for an imminent ovarian hyperstimulation was assumed if preovulatory estradiol levels rose up higher than 700 pg/ml and more than 12 intermediate sized follicles (8-14 mm) were observed. Thirty-six women received 0.5mg Triptorelin subcutaneously to trigger the ovulation inducing LH surge. After randomization, luteal support regimes started on day 2 after the Triptorelin administration with injections every second day five times in all. Group (a) received 5 x 1000 IU hCG, group (b) received 5 x 500 IU hCG, and group (c) received 5 x 250 mg progesterone, intramuscularly. The monitoring of the ovulation period and the subsequent luteal phase included sonographic measurement of ovarian diameter and estimation of LH, FSH, estradiol and progesterone levels 10 and 34 h as well as 8 days after Triptorelin administration.

RESULTS

We could prove ovulation in all women and did not find symptoms of ovarian hyperstimulation in any case. Midluteal controls showed extremely low gonadotropins in all groups indicating a long lasting pituitary down regulation after one injection of 0.5 mg Triptorelin. We found high normal sex steroid levels in both hCG groups. The progesterone group displayed a marked luteal phase defect with low levels of progesterone and estradiol in all cases.

CONCLUSION

The use of GnRH agonist in cases of polyfollicular development is capable to induce ovulation without a subsequent ovarian enlargement and/or any sign of hyperstimulation syndrome. Luteal support by low dose hCG does not counteract the benefit of GnRH agonist in preventing an ovarian hyperstimulation syndrome, but seems to remedy at least in part the possible deleterious effects of GnRH agonists on luteal functionality.

Short term suppression of follicular recruitment and spontaneous ovulation in the cat using levonorgestrel versus a GnRH antagonist

Suppression and subsequent rebound of ovarian activity using a progestin (levonorgestrel; Norplant) versus a GnRH antagonist (antide) was assessed in the domestic cat via fecal estradiol and progesterone metabolite analyses. Following an initial dose-response trial, queens were assigned to one of four treatments: (1) antide, two 6 mg/kg injections 15 days apart (n = 8 cats); (2) levonorgestrel, six silastic rods (36 mg levonorgestrel/rod) implanted for 30 days (n = 8); (3) control injections (n = 5); and (4) control implants (n = 5). Steroid metabolites were quantified from daily fecal samples for 90 days before, 30 days during, and 90 days after treatment. Antide and levonorgestrel inhibited estrous cyclicity in contrast to continued cyclicity in controls. Cats already at estradiol baseline in antide (n = 7) and levonorgestrel (n = 4) groups remained inhibited during treatment. In females with elevated estradiol levels at treatment onset (Day 0), a normal estradiol surge was completed before concentrations declined to baseline (approximately Days 5-7) and remained suppressed throughout the remaining treatment period. Additionally, 56% of treatment animals exhibited at least one spontaneous ovulation during the pre-treatment period, but no female ovulated during treatment with levonorgestrel or antide. Antide-treated cats exhibited lower (P < 0.05) baseline estradiol concentrations during treatment compared to pre- and post-treatment. In contrast, levonorgestrel induced elevations in baseline estradiol following treatment compared to pre- and during treatment intervals. Control females showed no change (P > 0.05) in baseline estradiol throughout the study period. All levonorgestrel and antide cats returned to estrus after treatment withdrawal. Results demonstrate that: (1) both antide and levonorgestrel are effective for inducing short-term suppression of follicular recruitment and ovulation in the cat; (2) inhibition is reversible; and (3) GnRH antagonists and progestins differentially regulate basal estradiol secretion. This study also confirmed a relatively high incidence of spontaneous ovulation in the cat, a species generally considered to be an induced ovulator.

Molecular biology of gonadotropin-releasing hormone (GnRH)-I, GnRH-II, and their receptors in humans

In human beings, two forms of GnRH, termed GnRH-I and GnRH-II, encoded by separate genes have been identified. Although these hormones share comparable cDNA and genomic structures, their tissue distribution and regulation of gene expression are significantly dissimilar. The actions of GnRH are mediated by the GnRH receptor, which belongs to a member of the rhodopsin-like G protein-coupled receptor superfamily. However, to date, only one conventional GnRH receptor subtype (type I GnRH receptor) uniquely lacking a carboxyl-terminal tail has been found in the human body. Studies on the transcriptional regulation of the human GnRH receptor gene have indicated that tissue-specific gene expression is mediated by differential promoter usage in various cell types. Functionally, there is growing evidence showing that both GnRH-I and GnRH-II are potentially important autocrine and/or paracrine regulators in some extrapituitary compartments. Recent cloning of a second GnRH receptor subtype (type II GnRH receptor) in nonhuman primates revealed that it is structurally and functionally distinct from the mammalian type I receptor. However, the human type II receptor gene homolog carries a frameshift and a premature stop codon, suggesting that a full-length type II receptor does not exist in humans.

Depot versus daily administration of gonadotrophin releasing hormone agonist protocols for pituitary desensitization in assisted reproduction cycles

BACKGROUND

Gonadotrophin-releasing hormone agonist (GnRHa) has been widely used in cycles of in vitro fertilization (IVF). Among the various types of GnRHa ovarian stimulation protocols, the long protocol presents the best clinical pregnancy rates per cycle initiated (GnRHa administration until the suppression of ovarian activity is evident, within approximately 14 days). There are two types of GnRHa administration that can be used to lead to hypophysis desensitization in the IVF cycle in the long protocol: one consisting of daily GnRHa low doses, and another with the administration of analogues in higher long-acting doses (depot). There are controversies in the data as far as the number of ampoules to be used in the cycles with the depot GnRHa treatment, as well as regarding the number of follicles made available, the number of oocytes, fertilization, implantation and pregnancy rates.

OBJECTIVES

The objective of this study is to compare the use of a single long-acting depot dose to that of daily GnRHa doses in in vitro fertilization cycles.

SEARCH STRATEGY

We searched the Cochrane Menstrual Disorders and Subfertility Group's specialised register of trials (searched 15 April 2004), Cochrane Central Register of Controlled Trials (Issue 2, 2004), MEDLINE (1984 to April 2004), EMBASE (1984 to June 2003), LILACS (1984 to April 2004) and reference lists of articles.

SELECTION CRITERIA

Types of studies: RCTs comparing depot and daily administration of GnRHa for long protocols in IVF treatment cycles.

TYPES OF PARTICIPANTS

Couples with any cause of infertility. Types of interventions: Ovarian stimulation with human follicle stimulating hormone (hFSH) and/or human menopausal gonadotropin (hMG) and/or recombinant follicle stimulating hormone (rFSH) in IVF treatment cycles. Types of outcome measures: Clinical pregnancy rates per woman, per oocyte retrieval procedure, per embryo transfer, number of oocytes retrieved, oocyte fertilization rates, ongoing/delivered pregnancy rates per cycle started, abortion rates, multiple pregnancy rates, number of ampoules of gonadotropin employed, ovarian hyperstimulation syndrome (OHSS) incidence rates, cost analysis and patient convenience.

DATA COLLECTION AND ANALYSIS

The reviewers evaluated allocation concealment, classified as adequate, uncertain or inadequate. Two reviewers extracted the data independently. All analyses were performed according to the intention-to-treat method.

MAIN RESULTS

Six studies, with a total of 552 women, were included and analysed. The studies do not indicate that there is statistically significant difference between the use of depot GnRHa or daily GnRHa in the primary outcome, clinical pregnancy rates per woman (OR 0.94, 95% CI 0.65 to 1.37). However, there was sufficient evidence that the use of depot GnRHa for pituitary desensitization in IVF cycles increased the number of gonadotrophins ampoules (WMD 3.30, 95% CI 1.27 to 5.34) and the duration of the ovarian stimulation (WMD 0.56, 95% CI 0.31 to 0.81), as compared with daily GnRHa.

AUTHORS' CONCLUSIONS

Although we recognise that the clinical pregnancy rates per woman are not the ideal primary outcome, we found no evidence of differences between the long protocol using depot or daily GnRHa for IVF cycles. However, the use of depot GnRHa is associated with increased requirements for gonadotrophins and a longer time required for ovarian stimulation. If these differences could be shown to translate into economic benefit, depot GnRHa should increase the overall costs of IVF treatment.

Estradiol and testosterone concentrations in follicular fluid as criteria to discriminate between mature and immature oocytes

The objective of the present study was to examine the association between follicular fluid (FF) steroid concentration and oocyte maturity and fertilization rates. Seventeen infertile patients were submitted to ovulation induction with urinary human follicle-stimulating hormone, human menopausal gonadotropin and human chorionic gonadotropin (hCG). A total of 107 follicles were aspirated after hCG administration, the oocytes were analyzed for maturity and 81 of them were incubated and inseminated in vitro. Progesterone, estradiol (E2), estrone, androstenedione, and testosterone were measured in the FF. E2 and testosterone levels were significantly higher in FF containing immature oocytes (median = 618.2 and 16 ng/ml, respectively) than in FF containing mature oocytes (median = 368 and 5.7 ng/ml, respectively; P < 0.05). Progesterone, androstenedione and estrone levels were not significantly different between mature and immature oocytes. The application of the receiver-operating characteristic curve statistical approach to determine the best cut-off point for the discrimination between mature and immature oocytes indicated levels of 505.8 ng/ml for E2 (81.0% sensitivity and 81.8% specificity) and of 10.4 ng/ml for testosterone (90.9% sensitivity and 82.4% specificity). Follicular diameter was associated negatively with E2 and testosterone levels in FF. There was a significant increase in progesterone/testosterone, progesterone/E2 and E2/testosterone ratios in FF containing mature oocytes, suggesting a reduction in conversion of C21 to C19, but not in aromatase activity. The overall fertility rate was 61% but there was no correlation between the steroid levels or their ratios and the fertilization rates. E2 and testosterone levels in FF may be used as a predictive parameter of oocyte maturity, but not for the in vitro fertilization rate.

Concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid and serum in relation to stimulation protocol and outcome of assisted reproduction treatment

In this prospective, randomized study, concentrations of gonadotrophins and steroids in pre-ovulatory follicular fluid (FF) and serum were related to type of stimulation protocol as well as to the outcome of assisted reproduction in 280 women subjected to the long protocol gonadotrophin-releasing hormone (GnRH) agonist pituitary down-regulation and ovarian stimulation with either human menopausal gonadotrophin (HMG) or recombinant FSH. In the women treated with HMG, concentrations of LH, FSH, oestradiol and androstenedione in FF were significantly higher, and those of human chorionic gonadotrophin (HCG) and progesterone significantly lower, than in the women treated with recombinant FSH (rFSH). More women became pregnant and delivered in the HMG than in the rFSH group. These differences, however, were not statistically significant. Concentrations of FSH in serum and of FSH and LH in FF were significantly higher in conception than in non-conception cycles, whereas all other hormone concentrations in FF and serum were similar. The present study demonstrates that the pre-ovulatory follicular fluid hormone profile is significantly influenced by the gonadotrophin preparation used for ovarian stimulation, and suggests that ovarian stimulation with HMG results in an intra-follicular hormone profile more similar to that characterizing conception cycles than stimulation with rFSH. However, as the present data represent means of FF hormone profiles, they do not allow the conclusion of a direct correlation between the intra-follicular concentration of a certain hormone and the ability of the corresponding embryo to implant and establish an ongoing pregnancy.

Lower levels of inhibin A and pro-alphaC during the luteal phase after triggering oocyte maturation with a gonadotropin-releasing hormone agonist versus human chorionic gonadotropin

OBJECTIVE

To investigate the effect of triggering oocyte maturation with GnRH agonist on corpus luteum function by measuring luteal phase levels of inhibin A and pro-alphaC.

DESIGN

Prospective randomized trial.

SETTING

In vitro fertilization (IVF) program at a university hospital.

PATIENT(S)

Infertile women undergoing IVF-ET treatment.

INTERVENTION(S)

Controlled ovarian hyperstimulation with FSH and GnRH antagonist, triggering of final oocyte maturation with either hCG (n = 8) or GnRH agonist (n = 8), IVF-ET, and collection of blood samples every 2-3 days during the luteal phase.

MEASUREMENTS AND MAIN RESULTS

Luteal phase serum levels of inhibin A and pro-alphaC, P, and E(2).

RESULT(S)

Levels of inhibin A, pro-alphaC, estrogen, and P were significantly lower from day 4 to day 14 after triggering final oocyte maturation by GnRH agonist compared with hCG. Maximal luteal serum inhibin A and pro-alphaC levels were 91.5 +/- 23.6 and 184.1 +/- 23.5 pg/mL in the GnRH agonist-treated women compared with 464.7 +/- 209.1 and 7,351.6 +/- 934.3 pg/mL in women treated with hCG.

CONCLUSION(S)

Triggering final oocyte maturation with GnRH agonist instead of hCG in IVF cycles dramatically decreases luteal levels of inhibins, reflecting significant inhibition of the corpus luteum function. This effect may explain, at least in part, the mechanism of ovarian hyperstimulation syndrome prevention by the use of GnRH agonist.

Gonadotropin-releasing hormone and reproductive medicine

The hypothalamic gonadotropin-releasing hormone (GnRH) is a key regulator of the reproductive system, mainly through its effects on pituitary luteinizing hormone (LH) and follicle-stimulating hormone (FSH) release. Gonadotropin-releasing hormone analogues are modifications of the natural decapeptide, being either agonists (GnRHa) or antagonists. GnRHa may imitate the native hormone and induce an endogenous LH surge; however, sustained treatment with GnRHa results in complete refractoriness of LH and FSH production. This aspect of GnRHa action is the main application of the GnRHa in reproduction today. The hypogonadotropic hypogonadal state that results from the sustained treatment is the basis for additional applications of the GnRHa. The agonists appear to be effective, to some extent, for the treatment of endometriosis and were proved to be beneficial prior to surgery for fibroma uteri. GnRHa is used in assisted reproduction for both induction of an endogenous LH surge and for induction of ovulation, and its capacity to cause refractoriness of the pituitary may be used to avoid a premature LH surge. It is suggested that the GnRHa have a direct effect on ovarian steroidogenesis, which is independent of its action on the pituitary. This unwanted effect and other possible drawbacks of the agonists are thought to be eliminated with the use of the antagonists. The mechanism of action of these antagonists is through competitive blocking of the GnRH receptor, which results in a rapid but reversible suppression of gonadotropin secretion. As for GnRHa, GnRH antagonists have been proven effective to prevent the LH surge and to reduce the incidence of severe ovarian hyperstimulation syndrome in controlled ovarian stimulation cycles.

Depot versus daily administration of gonadotrophin releasing hormone agonist protocols for pituitary desensitization in assisted reproduction cycles

BACKGROUND

Gonadotrophin-releasing hormone agonist (GnRHa) has been widely used in cycles of in vitro fertilization (IVF). Among the various types of GnRHa ovarian stimulation protocols, the long protocol presents the best clinical pregnancy rates per cycle initiated (GnRHa administration until the suppression of ovarian activity is evident, within approximately 14 days). There are two types of GnRHa administration that can be used to lead to hypophysis desensitization in the IVF cycle in the long protocol: one consisting of daily GnRHa low doses, and another with the administration of analogues in higher long-acting doses (depot). There are controversies in the data as far as the number of ampoules to be used in the cycles with the depot GnRHa treatment, as well as regarding the number of follicles made available, the number of oocytes, fertilization, implantation and pregnancy rates.

OBJECTIVES

The objective of this study is to compare the use of a single long-acting depot dose to that of daily GnRHa doses in in vitro fertilization cycles.

SEARCH STRATEGY

Relevant RCTs were identified by electronic search of the following databases: MEDLINE, EMBASE, LILACS (Latin American and Caribbean Center on Health Sciences Information) and the Cochrane Controlled Trials Register.

SELECTION CRITERIA

Types of studies: The study analyses RCTs comparing depot and daily administration of GnRHa for long protocols in IVF treatment cycles.

TYPES OF PARTICIPANTS

Couples with any cause of infertility. Types of interventions: Ovarian stimulation with human follicle stimulating hormone (hFSH) and/or human menopausal gonadotropin (hMG) and/or recombinant follicle stimulating hormone (rFSH) in IVF treatment cycles. Types of outcome measures: Clinical pregnancy rates per woman, per oocyte retrieval procedure, per embryo transfer, number of oocytes retrieved, oocyte fertilization rates, ongoing/delivered pregnancy rates per cycle started, abortion rates, multiple pregnancy rates, number of ampoules of gonadotropin employed, ovarian hyperstimulation syndrome (OHSS) incidence rates, cost analysis and patient convenience.

DATA COLLECTION AND ANALYSIS

The reviewers evaluated allocation concealment, classified as adequate, uncertain or inadequate. Two reviewers extracted the data independently. All analyses were performed according to the intention-to-treat method.

MAIN RESULTS

Six studies, with a total of 552 women, were included and analysed. The studies do not indicate that there is statistically significant difference between the use of depot GnRHa or daily GnRHa in the primary outcome, clinical pregnancy rates per woman (OR 0.94, 95% CI 0.65 to 1.37). However, there was sufficient evidence that the use of depot GnRHa for pituitary desensitization in IVF cycles increased the number of gonadotrophins ampoules (WMD 3.30, 95% CI 1.27 to 5.34) and the duration of the ovarian stimulation (WMD 0.56, 95% CI 0.31 to 0.81), as compared with daily GnRHa.

REVIEWER'S CONCLUSIONS

Although we recognise that the clinical pregnancy rates per woman are not the ideal primary outcome, we found no evidence of differences between the long protocol using depot or daily GnRHa for IVF cycles. However, the use of depot GnRHa is associated with increased requirements for gonadotrophins and a longer time required for ovarian stimulation. If these differences could be shown to translate into economic benefit, depot GnRHa should increase the overall costs of IVF treatment.

Human ovarian steroid secretion in vivo: effects of GnRH agonist versus antagonist (cetrorelix)

BACKGROUND

In order to investigate whether gonadotrophin-releasing hormone (GnRH) antagonists exert a significant effect on steroid secretion in vivo compared with GnRH agonists, concentrations of sex steroid hormones (oestradiol, progesterone and testosterone) were studied in follicular fluid from women undergoing ovarian stimulation and treated with either GnRH agonist or antagonist. In addition, the correlation between follicular fluid steroid hormone concentrations and variables of follicular and oocyte development was evaluated.

METHODS

Microparticle enzyme immunoassay and radioimmunoassays were used.

RESULTS

The mean (SEM) follicular fluid oestradiol concentration was significantly lower in patients treated with GnRH antagonist than in those treated with GnRH agonist (542.0 +/- 76.9 versus 873.0 +/- 105.1 pg/ml, P = 0.02), which correlates with the mean serum oestradiol concentrations found in these two groups. No significant differences were found between groups in follicular fluid progesterone concentrations. Women undergoing GnRH antagonist treatment showed similar concentrations of follicular fluid testosterone compared with GnRH agonist-treated women (14.8 +/- 1.1 versus 13.3 +/- 2.7 ng/ml). The oestradiol:testosterone ratio was markedly reduced in women treated with GnRH antagonist (49.1 +/- 2.3 versus 60.1 +/- 4.4, P = 0.04). In contrast, no differences were found either in the progesterone:testosterone ratio, or in the oestradiol:progesterone ratio.

CONCLUSIONS

GnRH antagonist therapy in women undergoing ovarian stimulation had a significant effect on ovarian follicular steroidogenesis.

Androgen deficiency in women

Physiological and pathological processes as well as iatrogenic interventions may result in androgen deficiency compared with levels in young healthy women. Whether relative androgen deficiency results in a clinical syndrome similar to that reported in men, including osteopenia, increased fat mass, decreased libido, and diminished quality of life, has not been definitively established. However, preliminary data in postmenopausal women suggest that physiological androgen replacement therapy, which involves substantially lower doses than those used in men, may result in increased bone mineral density, increased libido, and improved quality of life. The safety of androgen preparations that result in supraphysiological levels has not been established in women and would be expected to result in hirsutism, acne, and virilization with chronic use. Androgen preparations that avoid liver metabolism and result in physiological serum androgen levels in women with androgen deficiency are not currently available, but are in development. Therefore, although widespread screening and hormone replacement for androgen deficiency cannot be recommended yet, increasing interest in this topic makes consideration of the available data important.

Embryo implantation and GnRH antagonists: ovarian actions of GnRH antagonists

The gonadotrophin-releasing hormone (GnRH) antagonists, cetrorelix and ganirelix, have both been approved for ovarian stimulation to prevent a premature LH surge. Since GnRH receptors and their gene expression have been detected in human ovary, concern has risen over whether GnRH antagonists might affect ovarian function. Three large trials which compared GnRH agonists (used in the standard protocol worldwide), with the new antagonist treatment found no significant differences concerning the most important goals, e.g. pregnancy rate, fertilization and quality of oocytes. However, the concentration of oestradiol, and the pregnancy and implantation rates were lower in GnRH antagonist-treated patients. These findings again fuelled the debate about the possible extrapituitary effects of GnRH antagonists. Here, we review the conflicting data in the literature on the ovarian effects of GnRH antagonists and discuss our own results. In our view, it is unlikely that GnRH antagonists have a relevant impact on ovarian steroidogenesis and function; however, GnRH antagonists may exert other effects on the ovary.