Pharmacokinetic and pharmacodynamic characteristics of ganirelix (Antagon/Orgalutran). Part II. Dose-proportionality and gonadotropin suppression after multiple doses of ganirelix in healthy female volunteers

Testosterone-associated blood pressure dysregulation in women with androgen excess polycystic ovary syndrome

We tested the hypothesis that hyperandrogenemia in androgen excess polycystic ovary syndrome (AE-PCOS) is a primary driver in blood pressure (BP) dysregulation via altered sympathetic nervous system activity (SNSA), reduced integrated baroreflex gain and increased renin-angiotensin system (RAS) activation. We measured resting SNSA (microneurography), integrated baroreflex gain, and RAS with lower body negative pressure in obese insulin-resistant (IR) women with AE-PCOS [n = 8, 23 ± 4 yr; body mass index (BMI) = 36.3 ± 6.4 kg/m2] and obese IR controls (n = 7, control, 29 ± 7 yr; BMI = 34.9 ± 6.8 kg/m2), at baseline (BSL), after 4 days of gonadotropin-releasing hormone antagonist (ANT, 250 μg/day) and 4 days of ANT + testosterone (ANT + T, 5 mg/day) administration. Resting BP was similar between groups for systolic blood pressure (SBP; 137 ± 14 vs. 135 ± 14 mmHg, AE-PCOS, control) and diastolic BP (89 ± 21 vs. 76 ± 10 mmHg, AE-PCOS, control). BSL integrated baroreflex gain was similar between groups [1.4 ± 0.9 vs. 1.0 ± 1.3 forearm vascular resistance (FVR) U/mmHg], but AE-PCOS had lower SNSA (10.3 ± 2.0 vs. 14.4 ± 4.4 burst/100 heartbeats, P = 0.04). In AE-PCOS, T suppression increased integrated baroreflex gain, which was restored to BSL with ANT + T (4.3 ± 6.5 vs. 1.5 ± 0.8 FVR U/mmHg, ANT, and ANT + T, P = 0.04), with no effect in control. ANT increased SNSA in AE-PCOS (11.2 ± 2.4, P = 0.04). Serum aldosterone was greater in AE-PCOS versus control (136.5 ± 60.2 vs. 75.7 ± 41.4 pg/mL, AE-PCOS, control, P = 0.04) at BSL but was unaffected by intervention. Serum angiotensin-converting enzyme was greater in AE-PCOS versus control (101.9 ± 93.4 vs. 38.2 ± 14.7 pg/mL, P = 0.04) and reduced by ANT in AE-PCOS (77.7 ± 76.5 vs. 43.4 ± 27.3 µg/L, ANT, and ANT + T, P = 0.04) with no impact on control. Obese, IR women with AE-PCOS showed decreased integrated baroreflex gain and increased RAS activation compared with control.NEW & NOTEWORTHY Here we present evidence for an important role of testosterone in baroreflex control of blood pressure and renal responses to baroreceptor unloading in women with a common, high-risk androgen excess polycystic ovary syndrome (AE-PCOS) phenotype. These data indicate a direct effect of testosterone on the vascular system of women with AE-PCOS independent of body mass index (BMI) and insulin-resistant (IR). Our study indicates that hyperandrogenemia is a central underlining mechanism of heightened cardiovascular risk in women with PCOS.

Physiological and Pharmacological overview of the Gonadotropin Releasing Hormone

Gonadotropin-releasing Hormone (GnRH) is a decapeptide responsible for the control of the reproductive functions. It shows C- and N-terminal aminoacid modifications and two other distinct isoforms have been so far identified. The biological effects of GnRH are mediated by binding to high-affinity G-protein couple receptors (GnRHR), showing characteristic very short C tail. In mammals, including humans, GnRH-producing neurons originate in the embryonic nasal compartment and during early embryogenesis they undergo rapid migration towards the hypothalamus; the increasing knowledge of such mechanisms improved diagnostic and therapeutic approaches to infertility. The pharmacological use of GnRH, or its synthetic peptide and non-peptide agonists or antagonists, provides a valid tool for reproductive disorders and assisted reproduction technology (ART). The presence of GnRHR in several organs and tissues indicates additional functions of the peptide. The identification of a GnRH/GnRHR system in the human endometrium, ovary, and prostate has extended the functions of the peptide to the physiology and tumor transformation of such tissues. Likely, the activity of a GnRH/GnRHR system at the level of the hippocampus, as well as its decreased expression in mice brain aging, raised interest in its possible involvement in neurogenesis and neuronal functions. In conclusion, GnRH/GnRHR appears to be a fascinating biological system that exerts several possibly integrated pleiotropic actions in the complex control of reproductive functions, tumor growth, neurogenesis, and neuroprotection. This review aims to provide an overview of the physiology of GnRH and the pharmacological applications of its synthetic analogs in the management of reproductive and non-reproductive diseases.

Progestin-primed ovarian stimulation versus GnRH antagonist protocol in poor responders: Risk of premature LH surge and outcome of oocyte retrieval

PURPOSE

For poor ovarian responders (PORs), gonadotropin-releasing hormone (GnRH) antagonist was commonly used for prevention of premature LH surge during controlled ovarian stimulation (COS) over the past two decades. The application of progestin-primed ovarian stimulation (PPOS) recently increased, but the role of PPOS for PORs was uncertain. We aimed to analyze the incidence of premature luteinizing hormone (LH) surge and the outcome of oocyte retrieval among PPOS and GnRH antagonist protocol for PORs.

METHODS

This was a single-center retrospective study, which enrolled the PORs (defined by the Bologna criteria) undergoing COS with PPOS or flexible GnRH antagonist protocol during January 2018 to December 2021. We compared the incidence of premature LH surge (LH > 10 mIU/mL) and the outcome of oocyte retrieval between the PPOS group and the GnRH antagonist group.

RESULTS

A total of 314 women were recruited, with 54 in the PPOS group and 260 in the GnRH antagonist group. The PPOS group had lower incidence of premature LH surges compared with the GnRH antagonist protocol group (5.6% vs 16.9%, P value 0.035). There was no significant difference between the two groups regarding the number of oocytes retrieved (3.4 vs 3.8, P value 0.066) and oocyte retrieval rates (88.9% vs 88.0%, P value 0.711).

CONCLUSION

Compared with PPOS, GnRH antagonist protocol had higher risk of premature LH surges for PORs but may not affect pregnancy rates. PPOS is suitable for oocyte or embryo cryopreservation, but should not totally replace GnRH antagonist protocol for patients undergoing in vitro fertilization (IVF).

Migraine and infertility, merging concepts in women's reproductive health: A narrative review

OBJECTIVE

The objective is to examine issues around treating infertility in patients with migraine.

BACKGROUND

Women outnumber men in migraine diagnosis with a 3:1 ratio; the disease is commonly expressed in women of child-bearing age and is influenced by changes in circulating hormones. Infertility is also common, and the use of treatment options, such as assisted reproductive technology, have expanded exponentially in recent years.

METHODS

We summarized the literature around the effect of infertility treatments on headache in the general population and migraine population. We also discuss sociobehavioral, economic, and biological factors affecting fertility in patients with migraine, describe infertility protocols, and propose areas of focus for future research. We searched PubMed for the combined key terms in vitro fertilization or assisted reproductive technology AND migraine, or headache. The search included all dates and specified English-language results only.

RESULTS

Migraine may negatively influence family planning and fertility. Patients face obstacles stemming from the impact of migraine on social relationships and the interference of preventive medications on pregnancy. Migraine may also be associated with an increased prevalence of endocrine disorders which in turn affect fertility. Moreover, infertility treatments are associated with mild headache as a side effect. In addition, we found only one retrospective study demonstrating an increase in headache frequency during in vitro fertilization in the migraine population.

CONCLUSIONS

We determined that there is little research focused specifically on migraine headache exacerbation and other migraine-associated health outcomes with infertility treatment. This topic merits further interdisciplinary exploration.

Efficacy and safety of newly developed ganirelix acetate in infertile women for assisted reproductive technology: a prospective, randomised, controlled study

This study aimed to investigate the efficacy of Ganilever pre-filled syringe (PFS), a newly developed ganirelix acetate, for the inhibition of premature luteinising hormone (LH) surge in in vitro fertilisation (IVF). A prospective randomised controlled study was conducted (NCT03051087). A total of 236 women (Ganilever group: 114, Orgalutran group: 122) were finally analysed. The patients with LH of >10 mIU/mL on the day of human chorionic gonadotropin (hCG) injection were 0 (0.0%) and 3 (2.5%) in the Ganilever and Orgalutran groups, respectively (p= .25). The number of retrieved oocytes from two groups did not show any significant difference (12.0 ± 6.4 vs. 11.8 ± 6.3, p= .73). Furthermore, the two groups did not show significant differences in the number of good-quality oocytes and embryo, and the rate of fertilisation. Similar safety profiles were also observed. In conclusion, Ganilever PFS showed comparable IVF outcomes and safety profile in IVF, as compared to the Orgalutran. Impact StatementWhat is already known on this subject? Premature LH surge during controlled ovarian stimulation results in the induction of luteinisation of the immature follicles. Thus, gonadotrophin-releasing hormone (GnRH) antagonist protocol was suggested as an option for suppression of premature LH surge. Currently, one of GnRH antagonists being widely used is ganirelix acetate (Orgalutran^®; Organon, Oss, The Netherlands). Ganilever pre-filled syringe (PFS) is a newly developed GnRH antagonist containing ganirelix acetate as an active ingredient.What do the results of this study add? Our study demonstrated that Ganilever PFS showed comparable IVF outcomes and patient safety profile in infertile women undergoing in IVF-ET, as compared to the Orgalutran.What are the implications of these findings for clinical practice and/or further research? The results of our study will provide another available GnRH antagonist to be used in patients with IVF.

Therapeutic effects of an oral gonadotropin-releasing hormone receptor antagonist, relugolix, on preventing premature ovulation in mild ovarian stimulation for IVF

Purpose

Can relugolix, a novel oral gonadotropin-releasing hormone receptor (GnRH) antagonist, function as an alternative ovulation inhibitor to GnRH antagonist injections?

Methods

This single-center, cross-sectional retrospective study compared premature ovulation rates and clinical outcomes in IVF treatment after mild ovarian stimulation with 40 mg of relugolix (relugolix group) or 0.25-mg injections of ganirelix acetate or cetrorelix acetate (injection group) between March 2019 and January 2020. Of 247 infertile women (256 IVF cycles) aged ≤42 years, 223 women (230 cycles) were evaluated. In the relugolix and injection groups, we compared 104 and 85 cycles after GnRH antagonist use before the LH surge (LH levels <10 mIU/ml) and 22 and 19 cycles during the LH surge (LH levels ≥10 mIU/ml), respectively.

Results

Before the LH surge, the ovulation rates in the two groups were very low (p = 0.838), however; during the LH surge, the cycles using relugolix had a high ovulation rate of 40.9% compared with no ovulation in the injection group (p = 0.002). There were no significant differences in embryo culture findings and pregnancy outcomes between the two groups.

Conclusions

Although relugolix had a high ovulation suppressive effect, when the LH surge occurred, its effect was insufficient.

ETB receptor-mediated vasodilation is regulated by estradiol in young women

The endothelin-B (ET_B) receptor is a key regulator of vascular endothelial function in women. We have previously shown that the ET_B receptor mediates vasodilation in young women, an effect that is lost after menopause. However, the direct impact of changes in estradiol (E₂) on ET_B receptor function in women remains unclear. Therefore, the purpose of this study was to test the hypothesis that E₂ exposure modulates ET_B receptor-mediated dilation in young women. Fifteen young women (24 ± 4 yr, 24 ± 3 kg/m²) completed the study. Endogenous sex hormone production was suppressed with daily administration of a gonadotropin-releasing hormone antagonist (GnRHant; Ganirelix) for 10 days; E₂ (0.1 mg/day, Vivelle-Dot patch) was added back on days 4-10. We measured vasodilation in the cutaneous microcirculation (microvascular endothelial function) via local heating (42°C) on day 4 (GnRHant) and day 10 (GnRHant + E₂) using laser Doppler flowmetry coupled with intradermal microdialysis during perfusions of lactated Ringer's (control) and ET_B receptor antagonist (BQ-788, 300 nM). During GnRHant, vasodilatory responses to local heating were enhanced with ET_B receptor blockade (control: 83 ± 9 vs. BQ-788: 90 ± 5%CVC_max, P = 0.004). E₂ administration improved vasodilation in the control site (GnRHant: 83 ± 9 vs. GnRHant + E₂: 89 ± 8%CVC_max, P = 0.036). Furthermore, cutaneous vasodilatory responses during ET_B receptor blockade were blunted after E₂ administration (control: 89 ± 8 vs. BQ-788: 84 ± 8%CVC_max, P = 0.047). These data demonstrate that ovarian hormones, specifically E₂, modulate ET_B receptor function and contribute to the regulation of microvascular endothelial function in young women.NEW & NOTEWORTHY The endothelin-B (ETB) receptor mediates vasodilation in young women, an effect lost following menopause. It is unclear whether these alterations are due to aging or changes in estradiol (E2). During endogenous hormone suppression (GnRH antagonist), blockade of ETB receptors enhanced cutaneous microvascular vasodilation. However, during E2 administration, blockade of ETB receptors attenuated vasodilation, indicating that the ETB receptor mediates dilation in the presence of E2. In young women, ETB receptors mediate vasodilation in the presence of E2, an effect that is lost when E2 is suppressed.

The impact of indomethacin on the number of oocytes retrieved and IVF outcomes in patients with poor ovarian response

OBJECTIVE

The aim of this retrospective case-control study was to analyze the effect of administering indomethacin after triggering final oocyte maturation in patients with poor ovarian response (POR) on the cycle cancellation rate due to premature ovulation (PO), the number of oocytes retrieved and the clinical outcomes of IVF cycles.

STUDY DESIGN

A total of 214 patients with POR, diagnosed according to the Bologna criteria, who underwent fresh IVF cycle via flexible gonadotrophin-releasing hormone antagonist (GnRH-ant) protocol were enrolled in the study. The control group consisted of 100 patients, whereas the indomethacin group included 114 patients who received 100 mg rectal indomethacin administered twice within the same day (twelve hours apart) -starting at twelve hours after triggering. Cycle cancelation rates (CCR), number of oocytes retrieved (nOR), implantation rates (IR), biochemical pregnancy (BP) and clinical pregnancy loss rates (CPL), ongoing pregnancy rates (OPR) and live birth rates (LBR) were compared between the indomethacin and control groups.

RESULTS

The CCR rate was significantly lower in the indomethacin group (1.8%) compared to the control group (1.8% vs %12%, p = 0.01). In the control group, those with cycle cancellation were older than those without cycle cancellation (mean age 42.2 ± 2.3 years vs. 39.36 ± 4.3 years, p = 0.001) and had lower anti-Müllerian hormone levels and lower antral follicle count (0.59 ± 0.2 ng/mL vs 0.79 ± 0.2 ng/mL, p = 0.001 and 4 ± 0.6 vs 5.7 ± 1.7, p = 0.001, respectively). In multivariable analysis, when the dependent variable in the logistic regression model was coded as the absence of cycle cancellation, it was observed that only indomethacin had a statistically significant effect on cycle cancellation (β = -1.931, standard error = 0.832, Exp(B) = 0.145, p = 0.020). nOR was higher in the indomethacin group than control group but the difference did not reach significance (p = 0.07). Moreover, the IR, OPR and LBR, BP and CPL values were similar in the indomethacin and control groups (p > 0.05).

CONCLUSIONS

Based on data from this study, it can be concluded that indomethacin reduces cycle cancelation due to PO in patients with POR -without compromising implantation and pregnancy rates. However, further randomized controlled trials with larger sample sizes are required to clarify the definitive effect of indomethacin in the treatment of patients with POR.

Optimising Follicular Development, Pituitary Suppression, Triggering and Luteal Phase Support During Assisted Reproductive Technology: A Delphi Consensus

BACKGROUND

A Delphi consensus was conducted to evaluate global expert opinions on key aspects of assisted reproductive technology (ART) treatment.

METHODS

Ten experts plus the Scientific Coordinator discussed and amended statements plus supporting references proposed by the Scientific Coordinator. The statements were distributed via an online survey to 35 experts, who voted on their level of agreement or disagreement with each statement. Consensus was reached if the proportion of participants agreeing or disagreeing with a statement was >66%.

RESULTS

Eighteen statements were developed. All statements reached consensus and the most relevant are summarised here. (1) Follicular development and stimulation with gonadotropins (n = 9 statements): Recombinant human follicle stimulating hormone (r-hFSH) alone is sufficient for follicular development in normogonadotropic patients aged <35 years. Oocyte number and live birth rate are strongly correlated; there is a positive linear correlation with cumulative live birth rate. Different r-hFSH preparations have identical polypeptide chains but different glycosylation patterns, affecting the biospecific activity of r-hFSH. r-hFSH plus recombinant human LH (r-hFSH:r-hLH) demonstrates improved pregnancy rates and cost efficacy versus human menopausal gonadotropin (hMG) in patients with severe FSH and LH deficiency. (2) Pituitary suppression (n = 2 statements): Gonadotropin releasing hormone (GnRH) antagonists are associated with lower rates of any grade ovarian hyperstimulation syndrome (OHSS) and cycle cancellation versus GnRH agonists. (3) Final oocyte maturation triggering (n=4 statements): Human chorionic gonadotropin (hCG) represents the gold standard in fresh cycles. The efficacy of hCG triggering for frozen transfers in modified natural cycles is controversial compared with LH peak monitoring. Current evidence supports significantly higher pregnancy rates with hCG + GnRH agonist versus hCG alone, but further evidence is needed. GnRH agonist trigger, in GnRH antagonist protocol, is recommended for final oocyte maturation in women at risk of OHSS. (4) Luteal-phase support (n = 3 statements): Vaginal progesterone therapy represents the gold standard for luteal-phase support.

CONCLUSIONS

This Delphi consensus provides a real-world clinical perspective on the specific approaches during the key steps of ART treatment from a diverse group of international experts. Additional guidance from clinicians on ART strategies could complement guidelines and policies, and may help to further improve treatment outcomes.

Decline in endothelial function across the menopause transition in healthy women is related to decreased estradiol and increased oxidative stress

Endothelial function declines progressively across stages of the menopause transition; however, the mechanisms contributing to this decline are unknown. We hypothesized that differences in endothelial function among pre-, peri, and postmenopausal women are related to differences in estradiol and oxidative stress. Brachial artery flow-mediated dilation (FMD) was measured in 87 healthy women categorized by menopause stage (24 premenopausal, 17 early and 21 late perimenopausal, and 25 postmenopausal) before and after 3 days of ovarian hormone suppression (gonadotropin releasing hormone antagonist [GnRHant]) alone, and an additional 3 days of GnRHant with concurrent transdermal estradiol or placebo add-back treatment. In 82 women, FMD during acute vitamin C (antioxidant) infusion was measured before and after GnRHant + add-back. Before GnRHant, FMD was different among groups (p < 0.005; reduced across stages of menopause). Vitamin C increased FMD in late peri- and post- (p < 0.005) but not pre- or early perimenopausal women (p > 0.54). After GnRHant alone, FMD decreased in pre- and peri- (p < 0.01), but not postmenopausal women, and was restored to premenopausal levels by estradiol add-back in the pre- and perimenopausal groups. Vitamin C improved FMD in pre-, peri-, and postmenopausal women on GnRHant + placebo. There was no effect of vitamin C on FMD in women on GnRHant + estradiol. These observations support the concept that the decline in endothelial function across the menopause transition is related to the loss of ovarian estradiol. The decline in estradiol may alter redox balance, thereby increasing oxidative stress and impairing endothelial function.

[Effects of cetrorelix versus ganirelix in gonadotropin-releasing hormone antagonist cycles for preventing premature luteinizing hormone surges and on clinical outcomes of IVF-ET cycles]

OBJECTIVE

To compare the effects of cetrorelix and ganirelix in gonadotropin-releasing hormone antagonist (GnRH-ant) cycles for preventing premature luteinizing hormone (LH) surges and on clinical outcomes of IVF-ET cycles.

METHODS

We retrospectively analyzed 2572 GnRH-ant cycles of in vitro fertilization and embryo transfer from January, 2013 to December, 2016, including 1368 cycles with cetrorelix treatment and 1204 cycles with ganirelix treatment. The baseline characteristics of the patients and the clinical outcomes of the two groups were compared.

RESULTS

Compared with those receiving ganirelix treatment, the patients with cetrorelix treatment had a significantly younger age (33.10 vs 33.89 years, P < 0.001) and a lower body mass index (21.57 vs 21.84 kg/m2, P=0.024). After adjustment for age and body mass index of the patients, no significant differences were found between the two groups in the levels of follicle-stimulating hormone (FSH), LH, estradiol (E2), progesterone (P) levels either at the baseline or on the day of hCG triggering, or in the number of oocytes retrieved (P > 0.05). The two groups also had comparable percentages of patients with LH > 10 U/L on the day of hCG triggering (3.7% vs 3.2%) and similar spontaneous ovulation rate (0.6% vs 0.5%), clinical pregnancy rate (47.7% vs 45.9%) and live birth rate (37.5% vs 33.6%) following fresh embryo transfer (P > 0.05). The incidence of moderate to severe ovarian hyperstimulation syndrome, however, was significantly higher in ganirelix group than in cetrorelix group (0.7% vs 0.1%, P=0.006).

CONCLUSIONS

Cetrorelix and ganirelix can achieve comparable effects for preventing premature LH surges and can achieve similar clinical outcomes of GnRH-ant cycles, but ganirelix is associated with a significantly higher incidence of moderate to severe ovarian hyperstimulation syndrome.

Progestin vs. Gonadotropin-Releasing Hormone Antagonist for the Prevention of Premature Luteinizing Hormone Surges in Poor Responders Undergoing in vitro Fertilization Treatment: A Randomized Controlled Trial

Objective: Progestin was recently used as an alternative of gonadotropin-releasing hormone (GnRH) analog for preventing premature luteinizing hormone (LH) surge with the aid of vitrification techniques, however, limited data were available about the potential of progestin in poor responders undergoing in vitro fertilization (IVF)/intracytoplasmic sperm injection (ICSI) treatment. We performed a randomized parallel controlled trial to investigate the difference of progestin and GnRH antagonist in poor responders. Methods: A total of 340 poor responders who met with Bologna criteria were randomly allocated into the progestin-primed ovarian stimulation (PPOS) group and GnRH antagonist group. Fresh embryo transfer was preferred in the GnRH antagonist group and freeze-all was performed in the PPOS group. The primary outcome was the incidence of premature LH surge, secondary outcomes were the number of retrieved oocytes, the number of viable embryos and the pregnancy outcomes. Results: The results showed that the incidence of premature LH surge in PPOS group was lower than that in antagonist group (0 vs. 5.88%, P < 0.05). In PPOS group, the average numbers of oocytes and viable embryos were comparable to those in GnRH antagonist group (3.7 ± 2.6 vs. 3.4 ± 2.4; 1.6 ± 1.7 vs. 1.4 ± 1.3, P > 0.05), the live birth rate was similar between the two groups (21.8 vs. 18.2%, RR 1.25 (95% confidence interval 0.73, 2.13), P > 0.05). Conclusions: The study demonstrated that PPOS had a more robust control for preventing premature LH rise than GnRH antagonist in poor responders, but PPOS in combination with freeze-all did not significantly increase the probability of pregnancy than GnRH antagonist protocol for poor responders.

Reproductive hormone influences on thermoregulation in women

The present discussion reviews current knowledge regarding influences of the primary reproductive hormones on mechanisms of thermoregulatory control in women. The human body is remarkably capable of maintaining body temperature within a few tenths of a degree of normal (37°C) over a wide range of activity and environmental exposures; this regulation is accomplished via integration of central and peripheral thermal information at the preoptic area of the anterior hypothalamus (PO/AH). We describe both central and peripheral mechanisms involved in controlling thermoregulation in humans, and how these mechanisms are affected by sex and hormone exposure. Estrogens generally promote vasodilation, heat dissipation, and lower body temperature and progesterone or progestins generally have the opposite effect. Estrogens and progesterone/progestins can also interact with androgens; this is an important point because androgens in the body can increase in both older and younger women. The study of reproductive hormone (estrogens, progesterone, luteinizing, and follicle stimulating hormones) effects on body systems is challenging because of the complex and multifaceted influences of these hormones, both individually and in combination. Thus, a number of methods to alter hormone exposure are explained in this article. We conclude that men and women do not exhibit major quantitative differences in physiological thermoregulatory responses to exercise and/or body heating when factors such as fitness and body size are taken into account. However, female and male reproductive hormones have important influences that can significantly alter individual thermoregulatory responses at various points throughout the lifespan.

Challenges and methodology for testing young healthy women in physiological studies

Physiological responses and control of body systems differ between women and men. Moreover, within women, female gonadal hormones have important influences on organs and systems outside of reproduction. Until the NIH Revitalization Act of 1993, laboratories focused physiological research primarily on men, and this focus placed limitations on women's health care. Thus, the NIH directive to include women required scientists and physicians studying humans to consider female reproductive physiology. Even though this directive was enacted over 20 years ago, there is still a great deal of misunderstanding as to the best methods to control hormones or account for changes in internal hormone exposure in women. This discussion describes common methods investigators use to include women in physiological studies and to examine the impact of female reproductive hormone exposure for research purposes. In some cases, the goal is to control for phase of the cycle, so women are studied when the endogenous hormones should be similar to each other. When the goal of the research is to examine the effects of hormones on a physiological response, it is important to use methods that will change hormone exposure in a controlled fashion. We recommend a method that employs gonadotropin-releasing hormone (GnRH) agonist or antagonist to suppress estrogens, gonadotropins, progesterone, and androgens followed by administration of these hormones. While this method is more invasive, it is safe and is the strongest research design to examine both hormone effects within women and between women and men.

Effect of gonadotropin-releasing hormone antagonists on intrauterine insemination cycles in women with polycystic ovary syndrome: a meta-analysis

Polycystic ovary syndrome (PCOS) patients undergoing controlled ovarian stimulation and intrauterine insemination (COS/IUI) often face the risk of premature luteinization, which may result in lower pregnancy rate and higher miscarriage rate. This review was performed to identify if adjuvant treatment with GnRH antagonist (GnRH-ant) could effectively improve the clinical outcome of patients with PCOS undergoing COS/IUI. A literature search was conducted on the PubMed, EMBASE and Cochrane library databases. Two randomized controlled trials were included in this review, enrolling a total of 333 cycles. The patients who received GnRH-ant treatment had lower progesterone levels on the hCG day and a reduced premature luteinization rate. However, the rates of live birth, clinical pregnancy and miscarriage did not significantly differ between the GnRH-ant supplementation group and control group. In conclusion, although the existing randomized controlled trials indicate that GnRH-ant can effectively decrease the premature luteinizaton rate, evidence to support its use to improve clinical pregnancy outcomes in PCOS patients undergoing COS/IUI treatment is insufficient.

Androgens influence microvascular dilation in PCOS through ET-A and ET-B receptors

Hyperandrogenism and vascular dysfunction often coexist in women with polycystic ovary syndrome (PCOS). We hypothesized that testosterone compromises cutaneous microvascular dilation in women with PCOS via the endothelin-1 ET-B subtype receptor. To control and isolate testosterone's effects on microvascular dilation, we administered a gonadotropin-releasing hormone antagonist (GnRHant) for 11 days in obese, otherwise healthy women [controls, 22.0 (4) yr, 36.0 (3.2) kg/m(2)] or women with PCOS [23 (4) yr, 35.4 (1.3) kg/m(2)], adding testosterone (T; 2.5 mg/day) on days 8-11. Using laser Doppler flowmetry and cutaneous microdialysis, we measured changes in skin microcirculatory responsiveness (ΔCVC) to local heating while perfusing ET-A (BQ-123) and ET-B (BQ-788) receptor antagonists under three experimental conditions: baseline (BL; prehormone intervention), GnRHant (day 4 of administration), and T administration. At BL, ET-A receptor inhibition enhanced heat-induced vasodilation in both groups [ΔCVC control 2.03 (0.65), PCOS 2.10 (0.25), AU/mmHg, P < 0.05]; ET-B receptor inhibition reduced vasodilation in controls only [ΔCVC 0.98 (0.39), 1.41 (0.45) AU/mmHg for controls, PCOS] compared with saline [ΔCVC controls 1.27 (0.48), PCOS 1.31 (0.13) AU/mmHg]. GnRHant enhanced vasodilation in PCOS [saline ΔCVC 1.69 (0.23) AU/mmHg vs. BL, P < 0.05] and abolished the ET-A effect in both groups, a response reasserted with T in controls. ET-B receptor inhibition reduced heat-induced vasodilation in both groups during GnRHant and T [ΔCVC, controls: 0.95 (0.21) vs. 0.51 (13); PCOS: 1.27 (0.23) vs. 0.84 (0.27); for GnRHant vs. T, P < 0.05]. These data demonstrate that androgen suppression improves microvascular dilation in PCOS via ET-A and ET-B receptors.

Short-term administration of progesterone and estradiol independently alter carotid-vasomotor, but not carotid-cardiac, baroreflex function in young women

The individual effects of estrogen and progesterone on baroreflex function remain poorly understood. We sought to determine how estradiol (E2) and progesterone (P4) independently alter the carotid-cardiac and carotid-vasomotor baroreflexes in young women by using a hormone suppression and exogenous add-back design. Thirty-two young women were divided into two groups and studied under three conditions: 1) after 4 days of endogenous hormone suppression with a gonadotropin releasing hormone antagonist (control condition), 2) after continued suppression and 3 to 4 days of supplementation with either 200 mg/day oral progesterone (N = 16) or 0.1 to 0.2 mg/day transdermal 17β-estradiol (N = 16), and 3) after continued suppression and 3 to 4 days of supplementation with both hormones. Changes in heart rate (HR), mean arterial pressure (MAP), and femoral vascular conductance (FVC) were measured in response to 5 s of +50 mmHg external neck pressure to unload the carotid baroreceptors. Significant hormone effects on the change in HR, MAP, and FVC from baseline at the onset of neck pressure were determined using mixed model covariate analyses accounting for P4 and E2 plasma concentrations. Neither P4 (P = 0.95) nor E2 (P = 0.95) affected the HR response to neck pressure. Higher P4 concentrations were associated with an attenuated fall in FVC (P = 0.01), whereas higher E2 concentrations were associated with an augmented fall in FVC (P = 0.02). Higher E2 was also associated with an augmented rise in MAP (P = 0.01). We conclude that progesterone blunts whereas estradiol enhances carotid-vasomotor baroreflex sensitivity, perhaps explaining why no differences in sympathetic baroreflex sensitivity are commonly reported between low and high combined hormone phases of the menstrual cycle.

Early initiation of gonadotropin-releasing hormone antagonist treatment results in a more stable endocrine milieu during the mid- and late-follicular phases: a randomized controlled trial comparing gonadotropin-releasing hormone antagonist initiation on cycle day 2 or 6

OBJECTIVE

To compare the effect of initiating GnRH antagonist (GnRH-a) on cycle day (CD) 2 vs. CD 6 on LH, E₂, and P levels in the mid and late follicular phases.

DESIGN

Nested study within a multicenter randomized controlled trial.

SETTING

Reproductive medicine center in an university hospital.

PATIENT(S)

One hundred sixty patients undergoing IVF/intracytoplasmic sperm injection (ICSI).

INTERVENTION(S)

Recombinant FSH (150-225 IU) was administered daily from CD 2 onward. The study group (CD 2) started GnRH-a cotreatment on CD 2, whereas the control group (CD 6) started on CD 6.

MAIN OUTCOME MEASURE(S)

The follicular phase endocrine profile.

RESULT(S)

The LH levels on CD 6 were lower in the CD 2 group (0.6 ± 0.4 vs. 1.9 ± 1.4 IU/L). The CD 2 group demonstrated both lower E₂ levels on CD 6 (520.1 ± 429.6 pmol/L vs. 1,071.7 ± 654.2 pmol/L) and on the day of hCG administration (3,341.4 ± 1,535.3 pmol/L vs. 4,573.2 ± 2,445.4 pmol/L). The P levels did not differ on CD 6 or on the day of hCG administration.

CONCLUSION(S)

Early initiation of GnRH-a cotreatment results in a more stable endocrine profile, with more physiological levels of E2 and LH during the follicular phase. The effect on clinical outcomes must be established in larger trials.

CLINICAL TRIAL REGISTRATION NUMBER

NCT00866034.

Mechanisms contributing to low orthostatic tolerance in women: the influence of oestradiol

The impact of 17β-oestradiol (E2) exposure on autonomic control of orthostasis in young women is unclear. We tested the hypothesis that autonomic cardiovascular regulation is more sensitive to E2 exposure in women with low orthostatic tolerance. Women underwent an initial maximal lower body negative pressure (LBNP) test to place them into a low (LT, n = 7, 22 ± 1 years old, body mass index 22 ± 1 kg m(-2)) or a high orthostatic tolerance group (HT, n = 7, 22 ± 1 years old, body mass index 24 ± 1 kg m(-2)). We then suppressed endogenous reproductive hormone production using a gonadotrophin-releasing hormone antagonist (GnRHant) for 10 days, with E2 administration during the last 7 days of GnRHant. We measured R-R interval and beat-by-beat blood pressure during the modified Oxford protocol, and changes in heart rate, blood pressure and forearm vascular resistance (FVR) during submaximal LBNP. During submaximal LBNP, FVR increased in HT (ANOVA P < 0.05) but not in LT (ANOVA P > 0.05), and stroke volume was lower in LT relative to HT at all levels of LBNP (P < 0.05). Compared with GnRHant, E2 administration shifted FVR lower in LT (ANOVA P < 0.05), with no effect in HT. Administration of E2 increased baroreflex control of heart rate (derived from the modified Oxford protocol) in LT (GnRHant 10.7 ± 2.5 ms mmHg(-1) vs. E2 16.1 ± 2.4 ms mmHg(-1), P < 0.05) but not in HT (GnRHant 13.4 ± 1.9 ms mmHg(-1) vs. E2 15.3 ± 2.4 ms mmHg(-1), n.s.). In conclusion, blunted peripheral vasoconstriction and lower stroke volume contribute to compromised orthostatic tolerance in women; this inability to vasoconstrict is further exacerbated by exposure to E2. Furthermore, E2 administration increases baroreflex-mediated heart rate responses to orthostasis in low orthostatic tolerant women, which is likely to be a compensatory mechanism for the blunted peripheral vascular resistance and lower central volume.

Blood pressure and water regulation: understanding sex hormone effects within and between men and women

Cardiovascular disease remains the leading cause of death for both men and women. Hypertension is less prevalent in young women compared with young men, but menopausal women are at greater risk for hypertension compared with men of similar age. Despite these risks, women do not consistently receive first line treatment for the early stages of hypertension, and the greater morbidity in menopause reflects this neglect. This review focuses on ovarian hormone effects on the cardiovascular and water regulatory systems that are associated with blood pressure control in women. The study of ovarian hormones within young women is complex because these hormones fluctuate across the menstrual cycle, and these fluctuations can complicate conclusions regarding sex differences. To better isolate the effects of oestrogen and progesterone on the cardiovascular and water regulation systems, we developed a model to transiently suppress reproductive function followed by controlled hormone administration. Sex differences in autonomic regulation of blood pressure appear related to ovarian hormone exposure, and these hormonal differences contribute to sex differences in hypertension and orthostatic tolerance. Oestrogen and progesterone exposure are also associated with plasma volume expansion, and a leftward shift in the osmotic operating point for body fluid regulation. In young, healthy women, the shift in osmoregulation appears to have only a minor effect on overall body water balance. Our overarching conclusion is that ovarian hormone exposure is the important underlying factor contributing to differences in blood pressure and water regulation between women and men, and within women throughout the lifespan.

Low-dose GnRH antagonist protocol is as effective as the long GnRH agonist protocol in unselected patients undergoing in vitro fertilization and embryo transfer

OBJECTIVE

The present retrospective and controlled comparative study was designed to evaluate the pregnancy rate achieved using a modified, fixed, multiple-dose 0.125mg gonadotropin-releasing hormone (GnRH) antagonist protocol with the long GnRH agonist protocol as the control group.

MATERIALS AND METHODS

One hundred and twenty unselected women between 30 and 40 years of age, in their first cycle of IVF/ICSI, with a baseline follicle-stimulating hormone (FSH) <10 IU and an antral follicle count >3 were assigned into two groups: (1) the study group received 0.125mg of cetrorelix daily starting on Day 6 of stimulation; and (2) the control group received leuprolide daily starting in the mid-luteal phase of the preceding cycle. Both groups were given a flexible dose of recombinant FSH for stimulation. An ongoing pregnancy rate of more than 12 weeks was the primary outcome measure of the study.

RESULTS

Primary and secondary outcomes were comparable in both groups. A shorter duration of stimulation, a lower dosage of recombinant FSH consumption and a thinner endometrium on the day of human chorionic gonadotropin administration were all observed in the GnRH antagonist group.

CONCLUSION

A dosage of 0.125mg GnRH antagonist protocol was effective for these unselected patients during IVF/ET.

Short-term oral progesterone administration antagonizes the effect of transdermal estradiol on endothelium-dependent vasodilation in young healthy women

Very few studies have explored the cardiovascular effects of progesterone in premenopausal women. This study aimed to examine the short-term effects of oral progesterone alone, transdermal estrogen alone, and progesterone and estrogen combined on flow-mediated dilation (FMD) in healthy reproductive-aged women. We suppressed endogenous estrogens and progesterone in 17 premenopausal women for 10-12 days using a gonadotropin-releasing hormone antagonist. On day 4 (hormone suppression condition), subjects were tested (n = 17) and were then supplemented with either 200 mg micronized progesterone (n = 8) orally or 0.1 mg estradiol (n = 9) transdermally per day. On day 7 (progesterone-first or estradiol-first condition), subjects were tested and began supplementation with both hormones (n = 17) and were tested again on day 10 (combined hormone condition). FMD of the brachial artery was assessed using B-mode arterial ultrasound, combined with synchronized Doppler analysis. As a result, significant differences in FMD were observed between hormone suppression (7.85 ± 1.06%) and estrogen-first conditions (10.14 ± 1.40%; P < 0.05). The estradiol-induced increase was abolished when oral progesterone was also supplemented (6.27 ± 0.96%). In contrast, we observed a trend toward a decrease in FMD with unopposed progesterone administration, but no statistically significant differences were found between the progesterone-first (6.66 ± 1.23%), hormone suppression (7.80 ± 1.23%), and combined hormone conditions (7.40 ± 1.29%). In conclusion, these data suggest that short-term oral micronized progesterone administration antagonizes the beneficial effect of transdermal estradiol on FMD.

Administration of a gonadotropin-releasing hormone antagonist during the 3 days before the initiation of the in vitro fertilization/intracytoplasmic sperm injection treatment cycle: impact on ovarian stimulation. A pilot study

OBJECTIVE

To investigate the impact on the number of cumulus-oocyte complexes (COC) when a 3-day course of GnRH antagonist treatment precedes the initiation of controlled ovarian stimulation with gonadotropins in a GnRH antagonist protocol for IVF/intracytoplasmic sperm injection (ICSI).

DESIGN

Randomized controlled trial.

SETTING

Tertiary referral center.

PATIENT(S)

Sixty-nine women undergoing controlled ovarian hyperstimulation for IVF/ICSI.

INTERVENTION(S)

The control group (n = 36) received a standard treatment with daily injections of recombinant FSH (rFSH), starting on day 2 of the cycle at a dose of 150-225 IU/day, and GnRH antagonists from cycle day 7 onward. In the pretreatment group (n = 33), a GnRH antagonist was administered from day 2 of the menstrual cycle onward during 3 consecutive days; thereafter controlled ovarian stimulation was initiated with the same protocol as used in the control group.

MAIN OUTCOME MEASURE(S)

The primary endpoint was the number of COCs at egg retrieval.

RESULT(S)

Both groups had comparable baseline characteristics. The duration of rFSH stimulation and consumption of gonadotropins were similar in both groups. The number of COCs was higher in the pretreatment group (12.8; SD, 7.8) compared with in the control group (9.9; SD, 4.9), although this increment was not significant (between-group difference of 2.9 [95% confidence interval {CI} -0.2 to 6.0]). The ongoing pregnancy rates per started cycle of 14/33 (42%) versus 12/36 (33%) for pretreatment versus control did not differ significantly (between-group difference, 9.1%; 95% CI, -13% to 30%).

CONCLUSION(S)

Among women under 36 years old, early follicular phase GnRH antagonist pretreatment in a fixed GnRH antagonist protocol results in a trend toward a higher number of retrieved oocytes but does not yield significantly higher pregnancy rates.

Modified natural cycle for in vitro fertilization and embryo transfer in normal ovarian responders

Controlled ovarian hyperstimulation (COH) using a gonadotrophin-releasing hormone (GnRH) analogue plus gonadotrophins is used widely in in vitro fertilization (IVF), but there can be significant complications. Sixty women with a normal ovarian response participated in a comparison of COH (triptorelin [GnRH agonist] 0.1 mg/day SC from day 21 of the menstrual cycle [before the IVF cycle] and recombinant follicle-stimulating hormone (FSH) 150 - 300 IU/day from day 2 of the IVF cycle, when triptorelin was reduced to 0.05 mg/day) with a modified natural cycle (MNC) treatment (human menopausal gonado trophin [HMG] 150 IU/day IM if serum oestradiol was ≤ 50 pg/ml on day 2 or 3 of the menstrual cycle). The groups did not differ significantly in implantation rate (21.1% and 22.6%, respectively) and clinical pregnancy rate (30.0% and 30.0%, respectively). When comparing successful pregnancies, MNC patients had significantly lower values than COH patients for total amount of gonadotrophin (HMG and recombinant FSH) used, number of oocytes retrieved and medication cost. It is concluded that MNC seems to be a feasible treatment option, with low medication cost, relatively low risk of complications and, possibly, greater patient acceptability.

Progesterone enhances adrenergic control of skin blood flow in women with high but not low orthostatic tolerance

Women are more susceptible to orthostatic intolerance. Peripheral α-adrenergic responsiveness is important in orthostasis and is lower in women compared to men, and is modulated by female sex hormones. We tested the hypothesis that oestradiol attenuates peripheral cutaneous adrenergic responses in women with low orthostatic tolerance (LT), whereas progesterone enhances adrenergic responses in women with high orthostatic tolerance (HT). After completing a maximal lower body negative pressure test to determine level of orthostatic tolerance (cumulative stress index, CSI), women self administered a gonadotropin releasing hormone (GnRH) antagonist for 16 days to suppress endogenous sex hormone production. Oestradiol (E2, 0.2 mg day−1, patch; days 4–16), and progesterone (P4, 200 mg day−1, oral; days 12–16) were administered. Skin blood flow responses to graded intradermal microdialysis infusions of noradrenaline (NA) were measured during GnRH antagonist, E2, and E2+P4, in eight HT (s.e.m. = 22 ± 1 years, CSI −871 ± 86 mmHg min) and eight LT (21 ± 1 years, CSI −397 ± 65 mmHg min) women. In separate probes, NA was infused alone, and co-infused with the nitric oxide synthase inhibitor NG-monomethyl-l-arginine (l-NMMA, 10 mm), the non-selective cyclooxygenase inhibitor ketorolac tromethamine (Keto, 10 mm), and combined l-NMMA + Keto (10 mm each). Progesterone administration enhanced adrenergic responses in HT women (logEC50 GnRH −4.02 ± 0.39, E2+P4 −5.18 ± 0.31, P < 0.05); this response was reversed with Keto (E2+P4 logEC50 NA+Keto −3.82 ± 0.35, P < 0.05). In contrast, no change in adrenergic responsiveness occurred in LT women during any hormone condition. These data indicate differential regulation of cutaneous adrenergic responses by progesterone via the cyclooxygenase pathway in women with high and low orthostatic tolerance.

Greater exercise sweating in obese women with polycystic ovary syndrome compared with obese controls

PURPOSE

We examined estradiol and testosterone effects on thermoregulation in women with and without Polycystic Ovary syndrome (PCOS). We hypothesized that core temperature (Tc) threshold for sweating during exercise is delayed in women with PCOS and that testosterone delays the Tc set point for sweating during exercise.

METHODS

For 16 d, we suppressed estrogens, progesterone, and testosterone with a gonadotropin-releasing hormone antagonist (GnRHant) in seven women with and seven women without PCOS (control); we added 17[beta]-estradiol (0.2 mg.d-1, two patches) on days 4-16 (E2) and testosterone (2.5 mg.d-1, orally) on days 13-16 (E2 + T). Under each hormone condition, subjects cycled in a temperature of 35 degrees C at 60% of age-predicted HRmax for 40 min.

RESULTS

Tc sweating threshold was lower in women in the PCOS group compared with those in the control during GnRHant (37.21 degrees C +/- 0.51 degrees C vs 37.70 degrees C +/- 0.12 degrees C, P < 0.05); neither E2 nor E2 + T influenced the thermoregulatory responses in PCOS. E2 decreased Tc sweating threshold in control (37.06 degrees C +/- 0.69 degrees C, P < 0.05), but E2 + T attenuated this response (37.53 degrees C +/- 0.19 degrees C). Peak sweating rate was greater in women in the PCOS group compared with those in the control group during GnRHant (1.06 +/- 0.47 vs 0.47 +/- 0.11 mg.cm-2.min-1) and E2 + T (0.85 +/- 0.41 vs 0.44 +/- 0.10 mg.cm-2.min-1, P < 0.05). Compared with the control group, total sweat losses were greater in the PCOS group during GnRHant (0.614 +/- 0.189 vs 0.419 +/- 0.098 L) and during E2 + T (0.696 +/- 0.281 vs 0.434 +/- 0.164 L, P < 0.05) but not during E2 (0.639 +/- 0.231 and 0.505 +/- 0.214 L for PCOS and control groups, respectively, P = 0.09).

CONCLUSIONS

Thermoregulation was adequate in women with PCOS; however, the women with PCOS achieved thermoregulation at the expense of producing higher sweat volumes.

Sex hormone effects on body fluid and sodium regulation in women with and without exercise-associated hyponatremia

We hypothesized that exercise-associated hyponatremia (EAH) is a function of excess sodium loss combined with high water intake in women at risk for dysnatremias during endurance exercise. We further hypothesized that estradiol and progesterone exposure increases fluid retention and sodium loss during exercise in women at risk for EAH. For 16 days we suppressed estrogens and progesterone with a gonadotropin-releasing hormone antagonist (GnRH ant) in seven women with (Hypo) and nine women without (no Hypo) a history of hyponatremia; we added 17β-estradiol (0.2 mg/day patches) for days 4–16 (E2) and progesterone (200 mg/day) for days 13–16 (E2-P4). Under each hormone condition, subjects cycled in 35°C at 65% peak oxygen consumption (V̇o2peak) for 60 min, then at 55–60% V̇o2peak for 120 min. Subjects drank 8 ml/kg of water (and replenished urine volume) every 30 min over the final 120 min of exercise. S[Na+] fell by 4.3, 3.9, and 3.1 meq/l ( P < 0.05) with drinking during GnRH ant, E2, and E2-P4 in Hypo, with little fall in no Hypo. Under all conditions, combined urine and sweat sodium loss were similar between Hypo [−85.6 (SD 36.2), −86.4 (SD 39.2), and −112.0 (SD 30.0) meq] and no Hypo [−98.0 (SD 54.8), −80.9 (SD 57.6), and −105.1 (SD 46.4) meq, for GnRH, E2, and E2-P4], as was mass balance of electrolytes (EMB) for Hypo [−104.8 (SD 32.8), −103.6 (SD 42.1), and −132.8 (SD 34.9) meq] compared with no Hypo [−128.8 (SD 57.2), −113.5 (SD 61.1), and −143.4 (SD 49.6) meq for GnRH, E2, and E2-P4]. Mass balance of water [VMB, for Hypo, 0.42 (SD 0.10), 0.62 (SD 0.25), and −0.11 (SD 0.11) liter] compared with no Hypo [0.01 (SD 0.15), 0.03 (SD 17), and −0.16 (SD 0.13) liter for GnRH, E2, and E2-P4, P < 0.05] indicates water retention was the primary contributor to the lower S[Na+] in Hypo women.

Sex hormone effects on body fluid regulation

In young women, estradiol and progesterone primarily control reproduction, but they also affect fluid regulation. Estradiol lowers the operating point for osmoregulation of arginine vasopressin and thirst and increases plasma volume. Although total body water and sodium content are only mildly affected, data presented in this article suggest that reproductive hormones alter homeostatic set points for body fluid and tonicity.

Estrogen, medroxyprogesterone acetate, endothelial function, and biomarkers of cardiovascular risk in young women

Medroxyprogesterone acetate (MPA) is widely known for its use in combination hormone therapy for postmenopausal women. However, MPA is also commonly used in young women for contraception and treatment of a number of gynecological conditions. Despite its widespread use, the cardiovascular effects of MPA in young women are unclear. Therefore, the purpose of this study was to determine the acute effects of MPA when used in combination with estradiol on markers of cardiovascular risk in young women. We suppressed endogenous estrogens and progesterone in 10 premenopausal women using a gonadotropin-releasing hormone antagonist (GnRHa) for 10 days. On day 4 of GnRHa subjects received 0.1 mg of estradiol (GnRHa+E(2)), and on day 7 5 mg of MPA was added (GnRHa+E(2)+MPA). Endothelium-dependent vasodilation and endothelium-independent vasodilation of the brachial artery, lipids, homocysteine, high-sensitivity C-reactive protein, and endothelin-1 were assessed during treatment with GnRHa, GnRHa+E(2), and GnRHa+E(2)+MPA. Four additional subjects were tested to validate the efficacy of the GnRHa model and confirm the findings. Endothelium-dependent vasodilation was greater during GnRHa+E(2) than during GnRHa or GnRHa+E(2)+MPA (P = 0.006). Endothelin-1 was lower during GnRHa+E(2) than GnRHa alone (P = 0.039). Endothelin-1 increased with the addition of MPA and was not significantly different from GnRHa alone. There were no differences in the other markers of cardiovascular risk between hormone treatment days. These data suggest that acute MPA administration negates the beneficial effects of estradiol on endothelium-dependent vasodilation in young women. In addition, these data suggest that estradiol decreases endothelin-1 concentrations and the addition of MPA may counteract the effect of estradiol on endothelin-1.

Serum cetrorelix concentrations do not affect clinical pregnancy outcome in assisted reproduction

OBJECTIVE

To analyze the potential association between serum cetrorelix levels and clinical pregnancy outcome in patients who had undergone assisted reproduction cycles with a GnRH antagonist cetrorelix acetate 3-mg injection.

DESIGN

Retrospective case-control study.

SETTING

University-affiliated private-assisted reproduction center.

PATIENT(S)

130 IVF and intracytoplasmic sperm injection first cycles, treated with the same cetrorelix acetate protocol, in two matched groups according to whether the cycle resulted in clinical pregnancy (n = 56) or not (n = 74).

INTERVENTION(S)

Cetrorelix acetate administration at 3 mg in a sandwich protocol.

MAIN OUTCOME MEASURE(S)

Serum cetrorelix concentrations on the day of hCG administration with regard to clinical pregnancy outcome, pre- versus post-hCG percent change in serum E(2) levels and implantation rates.

RESULT(S)

The cetrorelix serum concentrations were in the range of 0.29 to 5.12 ng/mL. The comparisons between groups with and without clinical pregnancy revealed comparable serum cetrorelix levels. There was no significant correlation between the serum cetrorelix concentrations and percent change in pre- versus post-hCG serum E(2) levels. Serum cetrorelix levels were comparable among patients with various implantation rates.

CONCLUSION(S)

Although a wide range of serum cetrorelix levels could be detected during a GnRH antagonist cycle, these levels were comparable in patients with and without clinical pregnancies.

The effects of GnRH antagonist on the endometrium of normally menstruating women

PURPOSE

To study the effects of GnRH antagonist (ganirelix-Orgalutran) on the endometrium of regularly menstruating women.

MATERIALS AND METHODS

Prospective, self-controlled study. The thirty-five volunteers were studied for two cycles: one as a control and the other, GnRH antagonist-treated cycles in which ganirelix 0.25 mg/d was given daily for 3 days, starting when the largest follicle reached 15 mm. In both cycles, serum estradiol, LH and endometrial thickness were measured when the largest follicle was > or =18 mm. Endometrial biopsy was performed on day 6 after ovulation for histological dating and morphometric study.

RESULTS

No statistical differences between histological dating and the endometrial thickness in the control and GnRH antagonist-treated cycles. All morphometric parameters were also not different. Serum estradiol and LH levels were significantly lower in GnRH antagonist-treated cycles.

CONCLUSION

GnRH antagonist has no effect on the endometrium of regularly menstruating women as assessed by either histological dating or morphometric analysis.

Exogenous oestradiol and progesterone administration does not cause oedema in healthy young women

OBJECTIVE

Oedema is an increase in the extravascular component of extracellular fluid volume (ECFV). Fluid movement across the ECF is controlled by hydrostatic and oncotic pressures, which are influenced by oestradiol and progesterone. Thus we hypothesized that oestradiol decreases, while combined oestradiol + progesterone increases, protein and fluid movement out of the vasculature.

SUBJECTS

Subjects were eight healthy women (22 +/- 2 years).

DESIGN

Oestrogens and progesterone were suppressed with a gonadotropin-releasing hormone antagonist for 16 days; oestradiol (2 x 0.1 mg/day patches) was added for days 5-16 (E(2)) and progesterone (200 mg/day) was added for days 13-16 (E(2)-P(4)).

MEASUREMENTS

We estimated intravascular (plasma) volume (PV), transcapillary albumin escape rate (TER(alb)), and Starling forces (hydrostatic pressures of plasma and interstitium, plasma colloid pressure, capillary filtration coefficient) in the forearm on days 2 (GnRH antagonist), 9 (E(2)) and 16 (E(2)-P(4)).

RESULTS

In E(2), P([E2]) increased from 85 +/- 26 to 984 +/- 136 pmol/ml (P < 0.05), with no change in P([P4]). In E(2)-P(4), P([E2]) increased to 775 +/- 195 pmol/ml and P([P4]) increased from 6.4 +/- 3.2 to 43.8 +/- 16.2 nmol/l, P < 0.05). TER(alb) was lower during E(2) (5.1 +/- 0.9) and E(2)-P(4) (5.0 +/- 1.1) compared to GnRH antagonist (5.8 +/- 0.9%/h, P < 0.05). Plasma volume was unchanged by E(2), and showed a trend (P = 0.07) for an increase during E(2)-P(4) (48.2 +/- 2.9, 49.0 +/- 3.0 and 53.9 +/- 3.5 ml/kg for GnRH antagonist, E(2), E(2)-P(4), respectively). Starling forces were unaffected by hormone treatments. Plasma renin activity and serum aldosterone concentration increased during E(2)-P(4).

CONCLUSIONS

Neither E(2) nor E(2)-P(4) altered TER(alb) sufficiently to impact Starling forces indicating neither E(2) nor P(4) administration at these levels would likely cause oedema.

Preliminary report on the effect of a lower dose of gonadotropin-releasing hormone antagonist (cetrorelix) on ovarian hyperstimulation in lower-weight Asian women

OBJECTIVE

To determine the minimal effective daily dose of gonadotropin-releasing hormone (GnRH) antagonist in lower-weight Asian women undergoing controlled ovarian hyperstimulation (COH).

MATERIALS AND METHODS

A prospective randomized controlled trial of GnRH antagonist was performed. A total of 58 women with body weight of 40-50 kg accepted COH and transvaginal embryo transfer. Patients were divided into two groups: Group 1 patients (n = 28) were given a fixed cetrorelix dose of 0.2 mg/day; Group 2 patients (n = 30) were given a fixed cetrorelix dose of 0.15 mg/day. Cetrorelix was administered from menstrual day 8 until the day of human chorionic gonadotropin (hCG) administration. Serum luteinizing hormone (LH) and estradiol (E2) concentration were measured on the day of hCG administration. Gonadotropin dosages, LH and E2 concentrations, retrieved oocyte and embryo numbers, ovarian hyperstimulation syndrome (OHSS), embryo quality, and the rates of fertilization, implantation and pregnancy in both groups were compared.

RESULTS

The clinical pregnancy/implantation rates in Group 1 were higher than those in Group 2 (28.6%/10.4% vs. 20%/4.1%). The numbers of oocytes retrieved/Grade I-II embryos were higher in Group 1 than Group 2 (10.5/7.8 vs. 8.3/3.9). A lower percentage of LH surge and higher E2 levels on the day of hCG administration were observed in Group 1 compared to Group 2 (5.9%/1,610.8 pg/mL vs. 26.7%/1,023.6 pg/mL). There were no statistical differences between the two groups when comparing gonadotropin dosage and OHSS.

CONCLUSION

The lowest effective dosage of cetrorelix is 0.2 mg in COH and pituitary downregulation for lower-weight Asian women.

Precycle administration of GnRH antagonist and microdose HCG decreases clinical pregnancy rates without affecting embryo quality and blastulation

The outcome of a novel protocol utilizing precycle gonadotrophin-releasing hormone (GnRH) antagonist administration and LH activity support with microdose recombinant human chorionic gonadotrophin (HCG) was compared to GnRH agonist long protocol used in patients undergoing their first ICSI (n=707) or IVF (n=571) cycles, which had resulted in one or two blastocyst transfers. In GnRH antagonist cycles, cetrorelix acetate (3 mg) was administered s.c. 4 days before FSH stimulation and a repeat dose was given when the lead follicular diameter was 13-14 mm. LH support was provided by recombinant HCG (2.5 microg). Embryo progression and blastulation were evaluated using embryo progression indices and blastocyst quality scores. The tested protocol demonstrated reduced implantation and clinical pregnancy rates as compared with GnRH agonist long protocol, although the embryo progression and blastulation parameters and blastocyst quality were comparable among the groups. Logistic regression models further supported the significant negative impact of GnRH antagonist/microdose HCG protocol on clinical pregnancy rates in both ICSI and IVF patients. Assisted reproduction cycles with fresh blastocyst transfers utilizing precycle GnRH antagonist administration and microdose HCG support resulted in lower implantation and clinical pregnancy rates as compared with GnRH agonist cycles, although the embryo progression and blastulation parameters were comparable.

Aging attenuates both the regularity and joint synchrony of LH and testosterone secretion in normal men: analyses via a model of graded GnRH receptor blockade

Testosterone (T) secretion declines in the aging male, albeit for unknown reasons. From an ensemble perspective, repeated incremental signaling among gonadotropin-releasing hormone (GnRH), luteinizing hormone (LH), and T is required to maintain physiological androgen availability. Pattern-regularity statistics, such as univariate approximate entropy (ApEn) and bivariate cross-ApEn, provide specific and sensitive model-free measurement of altered multi-pathway control. The present study exploits partial muting of one pathway (GnRH drive) to appraise adaptive regulation of LH and T secretion in young and aging individuals. Analyses comprised 100 paired 18-h LH and T concentration time series obtained in 25 healthy men ages 20-72 yr each administered placebo and three graded doses of a specific GnRH-receptor antagonist. Graded blockade of GnRH drive increased the individual regularity of LH and T secretion and the synchrony of LH-T feedforward and T-LH feedback in the cohort as a whole (P<0.001 for each). However, age markedly attenuated ganirelix-induced enhancement of univariate T orderliness and bivariate LH-T feedback and T-LH feedback synchrony (P <or= 0.0025). In summary, the present analyses support the thesis that aging disrupts coordinate control of T secretion, LH-T feedforward, and T-LH feedback in healthy men. Thus the experimental strategy of stepwise silencing of an agonistic pathway may have utility in dissecting the bases of altered neurohormonal linkages in other systems.

Luteal hormonal profile of oocyte donors stimulated with a GnRH antagonist compared with natural cycles

The effect of gonadotrophin-releasing hormone (GnRH) antagonist treatment on luteal phase hormonal profile has not yet been fully investigated. Cycle characteristics of 23 fertile donors stimulated with recombinant FSH and the GnRH antagonist, ganirelix 0.25, for IVF and receiving no kind of luteal supplementation were compared with control, natural cycles. Luteal luteinizing hormone (LH) serum concentrations as well area under the curve (AUC) for LH were significantly higher in natural cycles. In addition, luteal phase length was longer in natural cycles compared with donor cycles. Luteinizing hormone values dropped in the luteal phase of the stimulated cycles, with the lowest values being observed in the mid-luteal phase. AUC for progesterone in the luteal phase was significantly higher in the stimulated cycles compared with natural cycles (P < 0.001). Low LH serum concentrations and shortened luteal phase indicate the need for luteal phase supplementation in GnRH antagonist IVF cycles.

LH suppression following different low doses of the GnRH antagonist ganirelix in polycystic ovary syndrome

Elevated LH concentration is a common feature in polycystic ovary syndrome (PCOS). This study was designed to establish whether elevated LH levels in PCOS might be suppressed to normal range values by the administration of different low doses of GnRH antagonist, which subsequently might reverse the anovulatory status of these patients. Twenty-four PCOS patients with elevated endogenous LH concentrations were randomized into 3 different dose groups, receiving either 0.125 mg (Group A), 0.250 mg (Group B) or 0.500 mg (Group C) ganirelix sc daily for 7 subsequent days. During the first day of treatment, LH and FSH levels were assessed at 20 min intervals, during 8 h. Thereafter LH, FSH, androgens, estradiol (E2) and inhibins were assessed daily and frequent ultrasound scans were performed for 7 days to record follicle development. Repeated GnRH antagonist administration induced a significant suppression of LH (and to a lesser extent of FSH) serum levels, which was comparable between the different doses. Six hours after ganirelix administration, endogenous LH was suppressed by 49, 69 and 75%, and endogenous FSH was suppressed by 23, 19 and 25%, respectively. The decrease in serum LH and FSH levels was transient and lasted for 12 h, after which serum levels returned to baseline levels at 24 h after drug administration. Androgen levels were not significantly suppressed using this regimen. E2 levels decreased significantly (p < 0.001) and suppression was most pronounced in Group C. Spontaneous follicle development or ovulations were not recorded during the course of treatment. In conclusion, the present study demonstrates that the GnRH antagonist ganirelix is capable of normalising elevated LH levels in PCOS patients, in doses similar to the ones previously shown to prevent a premature LH rise during ovarian hyperstimulation for in vitro fertilization (IVF). In addition, the transient suppression of elevated endogenous LH levels per se does not re-establish normal follicle development in PCOS. However, follicle development may be insufficiently supported by the accompanied subtle suppression of endogenous FSH. Similarly, a transient decline in E2 levels does not effectively restore normal pituitary ovarian feedback. Moreover, these results support the contention of a limited role of LH in the pathogenesis of PCOS.