Gonadotropin Surge-Attenuating Factor: A Nonsteroidal Ovarian Hormone Controlling GnRH-Induced LH Secretion in the Normal Menstrual Cycle

Unveiling the Neurotransmitter Symphony: Dynamic Shifts in Neurotransmitter Levels during Menstruation

The menstrual cycle is an intricate biological process governed by hormonal changes that affect different facets of a woman's reproductive system. This review provides an overview of neurotransmitter alterations during different menstrual cycle phases and their effects on physiology and psychology. During the follicular phase, rising estrogen levels increase serotonin synthesis, enhancing mood, cognition, and pain tolerance. Estrogen may also influence dopamine levels, promoting motivation and reward sensitivity. GABA, involved in anxiety regulation, may be modulated by estrogen, inducing relaxation. Ovulation involves fluctuating dopamine and serotonin levels, potentially affecting motivation and positive mood. In the luteal phase, rising estrogen and progesterone may reduce serotonin availability, contributing to mood dysregulation, while enhanced GABAergic neurotransmission promotes sedation. Menstruation is characterized by declining estrogen and progesterone, potentially leading to mood disturbances, fluctuating GABAergic and dopaminergic neurotransmitter systems, relaxation, fatigue, motivation, and pleasure variations. Understanding neurotransmitter alterations during the menstrual cycle unveils the neurobiological mechanisms behind menstrual-related symptoms and disorders, facilitating targeted interventions. Pharmacological approaches targeting neurotransmitter systems, nutritional interventions, and lifestyle modifications show promise in managing menstrual symptoms. Future research should focus on further understanding neurotransmitter dynamics, personalized medicine, unexplored neurotransmitter roles, and integrating psychosocial factors. This knowledge will enhance well-being and quality of life for individuals experiencing menstrual-related challenges.

Increasing dominant follicular proportion was associated with adverse IVF/ICSI outcomes in low-prognosis women undergoing GnRH antagonist protocol: a retrospective cohort study

PURPOSE

This study aimed to examine the correlation between different dominant follicle proportions (DFPs) and outcomes of in-vitro fertilization or intracytoplasmic sperm injection (IVF/ICSI) among patients classified under POSEIDON Groups 3 and 4, who underwent gonadotropin-releasing hormone antagonist (GnRH-ant) protocols. Additionally, it sought to determine the optimal DFP threshold for trigger timing.

METHODS

A retrospective analysis was performed on patients classified under POSEIDON Groups 3 (n = 593) and 4 (n = 563) who underwent GnRH-ant protocols for controlled ovarian hyperstimulation (COH) between 2016 and 2022. These patients were categorized into two groups based on their DFPs, defined as the ratio of ≥ 18-mm dominant follicles to ≥ 12-mm follicles on the trigger day (DFP ≤ 40% and DFP ≥ 40%). Statistical analyses, including restricted cubic spline (RCS) and multivariate logistic regression, were employed to assess the relationship between DFP and IVF/ICSI outcomes.

RESULTS

Demographic characteristics of patients were similar across groups. In POSEIDON Groups 3 and 4, DFP > 40 was associated with a significant decrease in the number (No.) of oocytes retrieved, cleaved embryos, and available embryos. Moreover, following the GnRH-ant cycle, the clinical pregnancy and live birth rates in fresh embryo transfer (ET) were notably reduced in the DFP > 40 group compared with the DFP ≤ 40 group, whereas no significant differences were observed in the pregnancy outcomes of the first frozen-thawed embryo transfer (FET) between the groups. In POSEIDON Group 3, the cumulative clinical pregnancy rate (CCPR) and cumulative live birth rate (CLRB) were significantly higher in the DFP ≤ 40 subgroup than in the DFP > 40 subgroup, with a notable decrease in CLRB observed with increasing DFP levels. However, in POSEIDON Group 4, no significant differences in CCPR and CLRB were found between the groups. Logistic regression analysis identified age and the No. of oocytes retrieved as pivotal factors influencing CLRB in Group 4.

CONCLUSION

For patients in POSEIDON Group 3, maintaining a DFP ≤ 40 mm is crucial to achieve optimal laboratory and pregnancy outcomes by avoiding delayed triggering. However, for patients in POSEIDON Group 4, age remains a critical factor influencing CLRB regardless of DFP, although a higher No. of oocytes retrieved and available embryos with DFP ≤ 40 is beneficial.

A critical signal for phenotype transition driven by negative feedback loops

The biological rhythms governed by negative feedback loops have undergone extensive investigation. However, developing reliable and versatile warning signals to predict periodic fluctuations in physiological processes and behaviors associated with these rhythms remains a challenge. Here, we monitored the heart rate and tracked ovulation dates of 91 fertile women. The finding strongly links the velocity (derivative) of heart rate with ovulation in menstrual cycles, providing a predictive warning signal. Similarly, an analysis of calcium signaling in the suprachiasmatic nucleus (SCN) of mice reveals that the maximum velocity of rising calcium signal aligns with locomotor activity offsets. To demonstrate the generality of derivative-transitions link, numerical simulations using a negative feedback loop model were conducted. Statistical analysis indicated that over 90% of the oscillations exhibited a correlation between maximum velocity and transition points. Consequently, the maximum velocity derived from oscillatory curves holds significant potential as an early warning signal for critical transitions.

The effect of luteinizing hormone changes in GnRH antagonist protocol on the outcome of controlled ovarian hyperstimulation and embryo transfer

BACKGROUD

To investigate the effect of Luteinizing hormone (LH) level changes on the outcomes of controlled ovarian hyperstimulation (COH) and embryo transfer (ET) in gonadotropin-releasing hormone antagonist (GnRH-ant) protocol.

METHODS

A total of 721 patients undergoing GnRH-ant protocol COH for the first IVF/ICSI cycles were retrospectively analyzed. COH process were divided into 2 stages, before (stage 1) and after (stage 2) the GnRH-ant initiation, and each with 5 groups basing on LH levels: LH decreased more than 50% (groups A1, A2), decreased 25-50% (groups B1, B2), change less than 25% (groups C1, C2), increased 25-50% (groups D1, D2), and increased more than 50% (groups E1, E2).

RESULTS

There were no significant differences among groups of stage1 regarding COH and ET outcomes. For stage 2, the more obvious the decrease of LH level, the more the number of oocytes retrieved, mature oocytes, fertilized oocytes, embryos cleavaged and the numbers of embryo available (P < 0.05), but without significant differences regarding ET outcomes. We also found the freeze-all rate in Group A2 was higher (P < 0.001).

CONCLUSION

LH level changes before GnRH-ant addition were not related to COH and ET outcomes. LH level changes after the addition of GnRH-ant were related to the outcome of COH, and no significant differences were found relating to ET outcomes.

Ovarian Stimulation with FSH Alone versus FSH plus a GnRH Antagonist for Elective Freezing in an Oocyte Donor/Recipient Programme: A Protocol for a Pilot Multicenter Observational Study

Preliminary data have shown that it is possible to attempt in vitro fertilization (IVF) treatment in fresh cycles without the use of a gonadotropin-releasing hormone (GnRH) antagonist or any other medication to prevent the luteinizing hormone (LH) surge during ovarian stimulation. To date, there is no information on this topic in the context of a prospective controlled trial. However, as prevention of the LH surge is an established procedure in fresh cycles, the question is whether such a study can be performed in frozen cycles. We aim to perform a pilot study in order to compare the efficacy of a protocol using FSH alone with that of a protocol using follicle-stimulating hormone (FSH) plus a GnRH antagonist for controlled ovarian hyperstimulation (COH) in cycles of elective freezing in the context of a donor/recipient program. This is a seven-center, two-arm prospective pilot cohort study conducted at the respective Assisted Reproductive Units in Greece. The hypothesis to be tested is that an ovarian stimulation protocol that includes FSH alone without any LH surge prevention regimens is not inferior to a protocol including FSH plus a GnRH antagonist in terms of the clinical outcome in a donor/recipient model. The results of the present study are expected to show whether the addition of the GnRH antagonist is necessary in terms of the frequency of LH secretory peaks and progesterone elevations >1 ng/mL during the administration of the GnRH antagonist according to the adopted frequency of blood sampling in all Units.

The effect of flexible low-dose GnRH antagonist on pregnancy outcome in the fresh embryo transfer cycle of IVF-ET: a randomized controlled trial

OBJECTIVE

To explore the practicality and effectiveness of a flexible low-dose protocol in the fresh embryo transfer cycle: reducing the total amount of antagonist by increasing the interval between administrations of Cetrotide.

METHODS

A total of 211 patients with normal ovarian reserve who accepted GnRH-ant protocol for IVF-ET were selected, and they were randomized to the flexible low-dose antagonist group (test group, n = 101) or the conventional dose antagonist group (control group, n = 110). The initial dose of Cetrotide in the test group was 0.25 mg every other day, and then the dose was adjusted to 0.25 mg every day based on the subsequent luteinizing hormone (LH) levels. The dosage of Cetrotide in the control group was 0.25 mg per day. The primary outcome was the clinical pregnancy rate. Secondary outcomes included the incidence of premature LH rise, total dosage of Cetrotide, number of oocytes retrieved, number of fertilized oocytes, number of high-quality embryos, biochemical pregnancy rate and ongoing pregnancy rate.

RESULTS

There was no significant difference in the general condition of the two groups. There was no significant difference in the clinical pregnancy rate (51.49% vs. 48.18%, p = 0.632) or the incidence of premature LH rise (18.81% vs. 15.45%, p = 0.584) between the two groups. However, the amount of Cetrotide used in the test group was significantly lower than that in the conventional dose antagonist group (1.13 ± 0.41 vs. 1.61 ± 0.59 mg, p < 0.001).

CONCLUSION

The flexible low-dose antagonist protocol and the conventional dose antagonist protocol were equally effective in people with a normal ovarian reserve in the fresh embryo transfer cycle of IVF-ET.

A flexible short protocol in women with poor ovarian response over 40 years old

BACKGROUND

Ovarian responsiveness to controlled ovarian stimulation is essential for a successful clinical outcome in assisted reproductive technology (ART) cycles. We aimed to find a suitable new ovulation stimulation protocol for poor ovarian response (POR) patients over 40 years old.

METHODS

A retrospective analysis of 488 ART cycles was evaluated from January 2015 to June 2019. Comparisons were made between the flexible short protocol (FSP), routine short protocol and mild stimulation protocol.

RESULTS

Compared with the routine short protocol, the FSP delayed the gonadotropin start time and reduced the total gonadotropin dose per stimulation cycle. At the same time, compared with the mild stimulation protocol, the FSP improved oocyte quality and embryo quality and improved embryo implantation potential after transfer. Furthermore, the use of the FSP reduced the probability of premature ovulation, as it inhibited the premature luteinizing hormone (LH) surge to a certain extent.

CONCLUSIONS

The FSP yielded better outcomes than other protocols for patients with POR over 40 years old in our study. However, further prospective studies are needed to provide more substantial evidence and to determine whether the FSP can be successful for both patients over 40 years group and younger POR patients.