Administration Of Progesterone Research Articles

Effect of duration of estradiol exposure on embryo survival and endometrial gene expression in anestrous embryo recipient mares

Previous studies indicate a positive correlation between the duration of estrus prior to ovulation and likelihood of pregnancy in embryo recipient mares. However, the mechanisms by which the duration of estrus before may affect fertility remains unclear. This study aimed to determine the effect of different durations of estradiol exposure, prior to progesterone administration, on embryo viability in anestrous recipient mares, and endometrial expression of genes thought to influence embryo survival. Three groups of anestrous recipient mares treated with different duration of estradiol were used: long (LE), short (SE) and no treatment (NE). Day 8 embryos were transferred into recipient mares four days after long-acting progesterone administration and recovered 48h later to examine embryo growth and viability. The endometrial gene expression profile of selected genes was also investigated. The likelihood of recovering an embryo 48h after transfer was 46.1% (6/13), 62.5% (5/8) and 85.7% (6/7) for recipient mares from the NE, SE and LE groups, respectively (P = .09). Embryos recovered from the different groups of recipients did not, however, differ in size, morphology or the proportion of nuclei undergoing mitosis (P > .05). Abundance of mRNA for uterocalin (P19) and insulin-like growth factor 1 (IGF1) were increased in the LE compared to the NE group, while fibroblast growth factor 2 (FGF2), progesterone receptor (PGR) and insulin-like growth factor 1 receptor (IGF1R) transcript abundances were increased (P < 0.05) in the NE group compared to both SE and LE groups. In conclusion, a longer exposure of the endometrium to estradiol before progesterone tended to improve embryo survival within 48h of transfer. However, the grade, growth rate, and proportion of mitotic cells in surviving embryos did not differ among groups. If embryos are destined to fail in a suboptimal endometrial environment, they die and disappear quickly. Moreover, a more adequately estradiol-primed uterus, before the progesterone rise, seems to create a uterine environment, in terms of P19, IGF1, FGF2 and PGR gene expression, more conducive to embryo survival and further development.

Vaginal microbiota and spontaneous preterm birth in pregnant women at high risk of recurrence

We describe vaginal microbiota, including Gardnerella species and sexually transmitted infections (STIs), during pregnancy and their associations with recurrent spontaneous preterm birth (sPTB). We performed a prospective cohort study in a tertiary referral centre in the Netherlands, among pregnant women with previous sPTB <34 weeks' gestation. Participants collected three vaginal swabs in the first and second trimester. Vaginal microbiota was profiled with 16S rDNA sequencing. Gardnerella species and STI's were tested with qPCR. Standard care was provided according to local protocol, including screening and treatment for bacterial vaginosis (BV), routine progesterone administration and screening for cervical length shortening. Of 154 participants, 26 (16.9 %) experienced recurrent sPTB <37 weeks' gestation. Microbiota composition was not associated with sPTB. During pregnancy, the share of Lactobacillus iners-dominated microbiota increased at the expense of diverse microbiota between the first and second trimester. This change coincided with treatment for BV, demonstrating a similar change in microbiota composition after treatment. In this cohort of high-risk women, we did not find an association between vaginal microbiota composition and recurrent sPTB. This should be interpreted with care, as these women were offered additional preventive therapies to reduce sPTB according to national guidelines including progesterone and BV treatment. The increase observed in L. iners dominated microbiota and the decrease in diverse microbiota mid-gestation was most likely mediated by BV treatment. Our findings suggest that in recurrent sPTB occurring despite several preventive therapies, the microbe-related etiologic contribution might be limited.

Midluteal serum estradiol levels are associated with live birth rates in hormone replacement therapy frozen embryo transfer cycles: a cohort study

ObjectiveTo study whether mid-luteal serum estradiol (E2) levels are associated with the Live Birth Rate in Hormone Replacement Therapy FET cycles in patients with optimal mid-luteal serum progesterone (P4) levels. DesignObservational prospective cohort study of 412 women having a Hormone Replacement Therapy FET single blastocyst transfer from January 2020 to November 2022. SubjectsThe Hormone Replacement Therapy FET priming regimen included oral estradiol (6mg/24h) administered in the evening, followed by vaginal progesterone (400mg/12h). Serum E2 and P4 levels were measured in a standardized manner, 2-4 hours after the latest progesterone administration and 9-14 hours after estradiol administration on the day of blastocyst transfer, day 6 of progesterone administration. Patients with serum P4 <11ng/mL (35nmol/l) on the day of transfer received additional rectal progesterone (400mg/12h). No additional estradiol was administered. Main Outcome MeasuresThe primary outcome was Live Birth Rate in relation to E2 levels at blastocyst transfer day. ResultsThe optimal serum E2 range correlating with ongoing pregnancy was ≥292pg/ml <409pg/ml (≥1070pmol/l and <1500pmol/l). The Live Birth Rate was 59% (60/102) if E2 levels were within this range, whereas a significantly lower Live Birth Rate of 39% (101/260, p=0.001) was seen in patients if E2 levels were <292pg/ml (<1070pmol/l), and of 28% (14/50, p<0.001) if E2 levels were ≥409pg/ml (≥1500pg/mL). In a logistic regression analysis, adjusting for serum progesterone level ≥11ng/mL or <11ng/mL (≥35nmol or <35nmol/l) on the day of transfer, BMI, age at oocyte retrieval, day 5 or 6 vitrified blastocyst and blastocyst score, the adjusted risk difference (RD) of a live birth was -0.21 [-0.32; -0.10] when the E2 level was <292pg/mL (<1070pmol/l) and -0.31 [-0.45; -0.18] if the E2 level was ≥409pg/ml (≥1500pmol/l) compared to E2 levels ≥292pg/ml <409pg/ml (≥1070 <1500pmol/l). Importantly, only 25% of patents had optimal levels. ConclusionThe study shows a significant association between serum E2 levels and reproductive outcomes in a Hormone Replacement Therapy FET cohort in which optimal serum progesterone levels were secured. Mid-luteal serum E2 levels are associated with Live Birth Rate in Hormone Replacement Therapy FET cycles and E2 levels should neither be too high nor too low.

Prenatal progesterone treatment modulates fetal brain transcriptome and impacts adult offspring behavior in mice

Maternal exposure to elevated levels of steroid hormones during pregnancy is associated with the development of chronic conditions in offspring that manifest in adulthood. However, the effects of progesterone (P4) administration during early pregnancy on fetal development and subsequent offspring behavior remain poorly understood. In this study, we aimed to investigate the effects of P4 treatment during early pregnancy on the transcript abundance in the fetal brain and assess the behavioral consequences in the offspring during adolescence and adulthood. Using RNA-seq analysis, we examined the impact of P4 treatment on the fetal brain transcriptome in a dosage-dependent manner. Our results revealed differential regulation of genes involved in neurotransmitter transport, synaptic transmission, and transcriptional regulation. Specifically, we observed bidirectional regulation of transcription factors (TFs) by P4 at different doses, highlighting the critical role of these TFs in neurodevelopment. To assess behavioral outcomes, we conducted open field and elevated plus maze tests. Offspring treated with low-dose P4 (LP4) displayed increased exploratory behavior during both adolescence and adulthood. In contrast, the high-dose P4 (HP4) group exhibited impaired exploration and heightened anxiety-like behaviors compared to the control mice. Moreover, in a novel object recognition test, HP4-treated offspring demonstrated impaired object recognition memory during both developmental stages. Additionally, both LP4 and HP4 groups showed reduced social interaction in the three-chamber test. These results suggest that prenatal exposure to P4 exerts a notable influence on the expression of genes associated with neurodevelopment and may induce alterations in behavioral characteristics in progeny, highlighting the need to monitor progesterone levels during pregnancy for long-term impacts on fetal brain development and behavior.

An in vitro validation system for chicken bioreactors using immortalized chicken oviductal epithelial cells

The utilization of chicken oviductal epithelial cells (OECs) as a bioreactor to produce therapeutic proteins has shown promise, but the time taken to obtain transgenic offspring impedes efficient validation of protein production. To overcome this barrier, we focused on the immortalization of chicken OECs (cOECs) using retroviral vector-mediated c-MYC oncogene expression to establish an in vitro pre-validation system for chicken bioreactors. The resulting immortalized cOECs exhibited sustained proliferation, maintained a normal diploid chicken karyotype, and expressed key oviduct-specific genes (OVA, OVM, LYZ, AVD, and ESR1). Notably, hormonal administration of diethylstilbestrol (DES) or progesterone (P4) upregulated oviduct-specific genes in these cells. To enhance the utility of these immortalized cOECs as an in vitro validation system for chicken bioreactors, clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) technology was employed to knock-in (KI) an enhanced green fluorescence protein (EGFP) gene at the ovalbumin (OVA) locus. The resulting OVA EGFP KI immortalized cOECs secreted both EGFP and OVA proteins into the culture medium, with secretion enhanced under DES treatment. This successful integration of an exogenous gene into cOECs enhances their potential as a versatile in vitro validation system for chicken bioreactors. The established immortalized cOECs overcome previous challenges associated with long-term culture and maintenance, providing a reliable platform for efficient protein production validation. This study presents a comprehensive characterization of the immortalized cOECs, addressing critical limitations associated with in vivo systems and laying a foundation for the development of a streamlined and effective chicken bioreactor model.

Antioxidative Effects of Hydro-Alcoholic Extract and Essential Oil of Quercus brantii Exerts Anti-Depressant-Like Effect and Improvement of Memory Defect in Progesterone-Induced Postpartum Depression in Rats

Background: Depression and memory disorders are known to be associated with increased oxidative stress. There is evidence suggesting that Quercus brantii (Q. brantii) possesses antioxidant properties. Objectives: This study aims to investigate the impact of Q. brantii hydro-alcoholic extract and oil on cognitive dysfunction in a postpartum depression (PPD) model and on oxidant/antioxidant activity in the hippocampus of adult female rats. Methods: Forty-two female Wistar rats (200 - 250 g) were randomly divided into six groups. PPD was induced by chronic intraperitoneal administration (5 days) of progesterone at a dose of 5 mg/kg, and three days after discontinuation, depressive behavior was assessed using a forced swimming test. Simultaneously, Quercus brantii hydro-alcoholic extract (100 mg/kg) and oil (45%) were administered. Spatial memory and locomotor activity were evaluated 24 hours after training using the Morris water maze and open field tests, respectively. The hippocampus tissue of all rats was used to evaluate oxidant-antioxidant factors, Vitamin D, and corticosterone levels. Results: Quercus brantii extract significantly reduced depression (P &lt; 0.05). Treatment with Q. brantii extract and oil improved spatial memory and learning (P &lt; 0.05). The Q. brantii extract increased levels of SOD, GSH, catalase, and vitamin D while decreasing MDA levels; additionally, Q. brantii oil increased SOD and vitamin D levels and decreased MDA levels in the brain (P &lt; 0.05). Conclusions: Quercus brantii extract and oil appear to have beneficial effects on learning and memory impairment in a PPD-induced model, which may be associated with their biochemical effects on the brain.

Does the route of administration matter? Systematic review and meta-analysis of randomized clinical trials between vaginal versus intramuscular progesterone administration in the prevention of preterm birth

Does the route of administration matter? Systematic review and meta-analysis of randomized clinical trials between vaginal versus intramuscular progesterone administration in the prevention of preterm birth

Progesterone induces neuroprotection associated with immune/inflammatory modulation in experimental traumatic brain injury.

An imbalance of immune/inflammatory reactions aggravates secondary brain injury after traumatic brain injury (TBI) and can deteriorate clinical prognosis. So far, not enough therapeutic avenues have been found to prevent such an imbalance in the clinical setting. Progesterone has been shown to regulate immune/inflammatory reactions in many diseases and conveys a potential protective role in TBI. This study was designed to investigate the neuroprotective effects of progesterone associated with immune/inflammatory modulation in experimental TBI. A TBI model in adult male C57BL/6J mice was created using a controlled contusion instrument. After injury, the mice received consecutive progesterone therapy (8 mg/kg per day, i.p.) until euthanized. Neurological deficits were assessed via Morris water maze test. Brain edema was measured via the dry-wet weight method. Immunohistochemical staining and flow cytometry were used to examine the numbers of immune/inflammatory cells, including IBA-1 + microglia, myeloperoxidase + neutrophils, and regulatory T cells (Tregs). ELISA was used to detect the concentrations of IL-1β, TNF-α, IL-10, and TGF-β. Our data showed that progesterone therapy significantly improved neurological deficits and brain edema in experimental TBI, remarkably increased regulatory T cell numbers in the spleen, and dramatically reduced the activation and infiltration of inflammatory cells (microglia and neutrophils) in injured brain tissue. In addition, progesterone therapy decreased the expression of the pro-inflammatory cytokines IL-1β and TNF-α but increased the expression of the anti-inflammatory cytokine IL-10 after TBI. These findings suggest that progesterone administration could be used to regulate immune/inflammatory reactions and improve outcomes in TBI.

Dynamic changes in AI-based analysis of endometrial cellular composition: Analysis of PCOS and RIF endometrium

BackgroundThe human endometrium undergoes a monthly cycle of tissue growth and degeneration. During the mid-secretory phase, the endometrium establishes an optimal niche for embryo implantation by regulating cellular composition (e.g., epithelial and stromal cells) and differentiation. Impaired endometrial development observed in conditions such as polycystic ovary syndrome (PCOS) and recurrent implantation failure (RIF) contributes to infertility. Surprisingly, despite the importance of the endometrial lining properly developing prior to pregnancy, precise measures of endometrial cellular composition in these two infertility-associated conditions are entirely lacking. Additionally, current methods for measuring the epithelial and stromal area have limitations, including intra- and inter-observer variability and efficiency. MethodsWe utilized a deep-learning artificial intelligence (AI) model, created on a cloud-based platform and developed in our previous study. The AI model underwent training to segment both areas populated by epithelial and stromal endometrial cells. During the training step, a total of 28.36 mm2 areas were annotated, comprising 2.56 mm2 of epithelium and 24.87 mm2 of stroma. Two experienced pathologists validated the performance of the AI model. 73 endometrial samples from healthy control women were included in the sample set to establish cycle phase-dependent dynamics of the endometrial epithelial-to-stroma ratio from the proliferative (PE) to secretory (SE) phases. In addition, 91 samples from PCOS cases, accounting for the presence or absence of ovulation and representing all menstrual cycle phases, and 29 samples from RIF patients on day 5 after progesterone administration in the hormone replacement treatment cycle were also included and analyzed in terms of cellular composition. ResultsOur AI model exhibited reliable and reproducible performance in delineating epithelial and stromal compartments, achieving an accuracy of 92.40% and 99.23%, respectively. Moreover, the performance of the AI model was comparable to the pathologists’ assessment, with F1 scores exceeding 82% for the epithelium and >96% for the stroma. Next, we compared the endometrial epithelial-to-stromal ratio during the menstrual cycle in women with PCOS and in relation to endometrial receptivity status in RIF patients. The ovulatory PCOS endometrium exhibited epithelial cell proportions similar to those of control and healthy women’s samples in every cycle phase, from the PE to the late SE, correlating with progesterone levels (control SE, r2 = 0.64, FDR < 0.001; PCOS SE, r2 = 0.52, FDR < 0.001). The mid-SE endometrium showed the highest epithelial percentage compared to both the early and late SE endometrium in both healthy women and PCOS patients. Anovulatory PCOS cases showed epithelial cellular fractions comparable to those of PCOS cases in the PE (Anovulatory, 14.54%; PCOS PE, 15.56%, p = 1.00). We did not observe significant differences in the epithelial-to-stroma ratio in the hormone-induced endometrium in RIF patients with different receptivity statuses. ConclusionThe AI model rapidly and accurately identifies endometrial histology features by calculating areas occupied by epithelial and stromal cells. The AI model demonstrates changes in epithelial cellular proportions according to the menstrual cycle phase and reveals no changes in epithelial cellular proportions based on PCOS and RIF conditions. In conclusion, the AI model can potentially improve endometrial histology assessment by accelerating the analysis of the cellular composition of the tissue and by ensuring maximal objectivity for research and clinical purposes.

Multi-faceted Anti-obesity Effects of N-Methyl-D-Aspartate (NMDA) Receptor Modulators: Central-Peripheral Crosstalk.

Hypothalamus is central to food intake and satiety. Recent data unveiled the expression of N-methyl-D-aspartate receptors (NMDAR) on hypothalamic neurons and their interaction with GABAA and serotoninergic neuronal circuits. However, the precise mechanisms governing energy homeostasis remain elusive. Notably, in females, the consumption of progesterone-containing preparations, such as hormonal replacement therapy and birth control pills, has been associated with hyperphagia and obesity-effects mediated through the hypothalamus. To elucidate this phenomenon, we employed the progesterone-induced obesity model in female Swiss albino mice. Four NMDAR modulators were selected viz. dextromethorphan (Dxt), minocycline, d-aspartate, and cycloserine. Obesity was induced in female mice by progesterone administration for 4 weeks. Mice were allocated into 7 groups, group-1 as vehicle control (arachis oil), group-2 (progesterone + arachis oil), and group-3 as positive-control (progesterone + sibutramine); other groups were treated with test drugs + progesterone. Various parameters were recorded like food intake, thermogenesis, serum lipids, insulin, AST and ALT levels, organ-to-body weight ratio, total body fat, adiposity index, brain serotonin levels, histology of liver, kidney, and sizing of fat cells. Dxt-treated group has shown a significant downturn in body weight (p < 0.05) by a decline in food intake (p < 0.01), organ-to-liver ratio (p < 0.001), adiposity index (p < 0.01), and a rise in body temperature and brain serotonin level (p < 0.001). Dxt demonstrated anti-obesity effects by multiple mechanisms including interaction with hypothalamic GABAA channels and anti-inflammatory and free radical scavenging effects, improving the brain serotonin levels, and increasing insulin release from the pancreatic β-cells.

Progesterone Hypersensitivity in Assisted Reproductive Technologies: Implications for Safety and Efficacy.

The global rise in the age of childbirth, influenced by changing sociodemographic patterns, has had a notable impact on fertility rates. Simultaneously, assisted reproductive techniques (ARTs) have become increasingly prevalent due to advancements in reproductive medicine. The paper explores the intersection between the surge in ARTs and the rising number of iatrogenic autoimmune progesterone dermatitis (APD). Autoimmune progesterone dermatitis, commonly known as progesterone hypersensitivity, manifests itself as a mucocutaneous hypersensitivity syndrome. It is characterized by a wide range of dermatological symptoms, with urticaria and maculopapular rashes being the most prominent signs. Concurrently, systemic symptoms, such as fever, angioedema, and, in severe instances, anaphylaxis, may ensue. This dermatologic condition poses a significant challenge to women of childbearing age. This intricate syndrome frequently manifests itself in conjunction with menstruation or pregnancy as a reaction to physiological fluctuations in endogenous progesterone. However, given that exposure to exogenous progesterone is an integral component of various modern therapies, secondary APD has also been described. Our findings unveil a heightened likelihood of developing secondary progesterone hypersensitivity in ART patients that is attributed to the administration of exogenous progesterone through intramuscular, intravaginal, and oral routes. The study also explores available therapeutic interventions for facilitating viable pregnancies in individuals grappling with autoimmune progesterone dermatitis within the context of ARTs. This comprehensive analysis contributes valuable insights into the intricate relationship between reproductive technologies, dermatological challenges, and successful pregnancy outcomes.

Cervical elastography in predicting spontaneous preterm birth in singleton pregnancy with a short cervix receiving progesterone treatment at 18 to 24 weeks’ gestation

Background A short cervix in the second trimester is known to increase the risk of preterm birth, which can be reduced with the administration of vaginal progesterone. However, some studies have suggested that a significant number of cases still experience preterm birth despite progesterone treatment. Objective This study was aimed to investigate the potential value of transvaginal cervical elasticity measured by E-Cervix as a predictor for spontaneous preterm birth (sPTB) in singleton pregnancies receiving progesterone treatment for a short cervix (CL ≤ 2.5 cm) diagnosed at 18 to 24 weeks’ gestation. Study design This prospective study was conducted at a single center premature high-risk clinic from January 2020 to July 2022. Singleton pregnancies with a short cervix at 18 to 24 weeks’ gestation were enrolled. Cervical elastography using E-Cervix was performed, and maternal and neonatal demographic characteristics, cervical length (CL), elasticity contrast index (ECI), cervical hardness ratio, mean internal os strain (IOS), and mean external os strain (EOS) were compared before and after progesterone treatment in sPTB and term birth groups. Multivariate logistic regression was used to analyze the association between elasticity parameters and spontaneous preterm birth. The screening performance of CL and optimal cervical elasticity parameters in predicting sPTB was evaluated using receiver-operating characteristic (ROC) curve analysis. Results A total of 228 singleton pregnant women were included in the study, among which 26 (11.4%) had sPTB. There were no significant differences in maternal characteristics and gestational age at enrollment between women with and without sPTB. At the start of progesterone treatment, there were no significant differences in cervical elasticity parameters between the two groups. After two weeks of progesterone treatment, women who had sPTB showed significantly higher levels of ECI, IOS, EOS (p = 0.0108, 0.0001, 0.016), and lower hardness ratio (p = 0.011) compared to those who had a full-term birth. Cervical length did not show significant differences between the two groups, regardless of whether progesterone treatment was administered before or after. Among the post-treatment cervical elasticity parameters, IOS and EOS were associated with a 3.38-fold and 2.29-fold increase in the risk of sPTB before 37 weeks (p = 0.032, 0.047, respectively). The AUROC of the combined model including CL, IOS, and EOS (0.761, 95% CI0.589–0.833) was significantly higher than the AUROC of CL alone (0.618, 95% CI 0.359–0.876). At a fixed false-positive of 13%, the addition of IOS and EOS in the CL model increased sensitivity from 34.6% to 57.6%, PPV from 25.7% to 36.5%, and NPV from 91.1% to 94.1%. Conclusion When assessing the risk of sPTB in singleton pregnancies with a short cervix receiving progesterone therapy, relying solely on cervical length is insufficient. It is crucial to also evaluate cervical stiffness, particularly the strain of the internal and external os, using cervical elastography.

Efficacy and prognostic factors of combined administration of progesterone and estriol valerate tablets for preventing intrauterine adhesions in patients with early missed abortion following dilation and curettage.

To investigate the therapeutic efficacy and prognostic factors of combined administration of estriol valerate tablets and progesterone for the prevention of intrauterine adhesions (IUA) in patients with early missed abortion (EMA) after dilation and curettage. Clinical data of 120 EMA patients undergoing dilation and curettage at Ganzhou People's Hospital from July 2021 to June 2023 were collected for this retrospective study. The 120 enrolled patients were divided into two groups, with 70 patients in the study group receiving both estriol valerate tablets and progesterone for the prevention of IUA, and 50 in the control group undergoing no such treatments at all. The therapeutic efficacy of IUA prevention in patients was compared between the two groups. Subsequently, patients who developed IUA were categorized into the adhesion group (n = 23) and those who did not into the non-adhesion group (n = 97). The clinical data of patients were compared between the adhesion group and the non-adhesion group. Both univariate and multivariate logistic regression analyses were performed to identify the risk factors of IUA in patients with EMA after dilation and curettage. Receiver Operating Characteristic (ROC) curves were drawn to analyze the predictive value of independent risk factors for IUA in patients with EMA after dilation and curettage. The study group showed a notably higher excellent and good response rate than the control group in IUA prevention (92.00% vs. 82.00%, P = 0.035). Logistic regression analysis revealed that a history of multiple previous miscarriages (P: 0.018; OR: 0.120; 95% CI: 0.02-2.119), relatively small endometrial volume (P: 0.001; OR: 0.026; 95% CI: 0.003-0.210), relatively thin endometrial thickness (P: 0.001; OR: 32.123; 95% CI: 4.339-237.807) and lack of preventive treatment (P: 0.051; OR: 0.211; 95% CI: 0.048-0.935) were independent risk factors for the occurrence of IUA in patients with EMA after dilation and curettage. ROC curve-based analysis showed that these risk factors; encompassing, the number of previous miscarriages, endometrial volume, endometrial thickness and preventive treatment, had a notably higher efficacy in jointly predicting the occurrence of IUA in EMA patients following dilation and curettage in comparison to an individual risk factor alone. The occurrence of IUA in patients with EMA following dilation and curettage is influenced by several factors, including the number of previous miscarriages, the volume and thickness of the endometrium, and preventive treatments. To minimize the risk of IUA, it is crucial to implement proactive interventions prior to uterine surgeries. It was found that a combination therapy involving estriol valerate tablets and progesterone could effectively prevent the development of IUA in patients with EMA after dilation and curettage.

Individualized luteal phase support in frozen-thawed embryo transfer after intramuscular progesterone administration might rectify live birth rate.

The serum P concentrations are suggested to have an impact on pregnancy outcome. However there is no consensus about the optimal progesterone cut-off during the luteal phase. Few studies evaluated the effectiveness of a "rescue protocol" for low serum P concentrations and most of these studies used vaginal progesterone administration. There is paucity of data on the effectiveness of rescue protocol using intramuscular progesterone (IM-P) in frozen-thawed embryo transfer (FET). This study is a retrospective cohort study included 637 single or double blastocyst FETs with artificially prepared endometrium receiving 100 mg IM progesterone (P) after incremental estrogen treatment. Serum P concentrations were evaluated using blood samples obtained 117-119 hours after the first IM-P administration and 21 ± 2 hours after the last IM-P administration. Patients with serum P concentrations <20.6 ng/ml on the ET day were administrated 400 mg vaginal progesterone for rescue. Demographic and cycle characteristics were similar between patients receiving rescue vaginal P (embryo transfer (ET)-day P concentration < 20.6 ng/ml) and patients who did not need rescue vaginal P (ET-day P concentration ≥ 20.6 ng/ml). Clinical pregnancy, miscarriage, and live birth rates were similar between two groups: 52.9%(45/85) vs 59.6%(326/552), p=0.287; 11.1%(5/45) vs 14.1%(46/326), p=0.583; and 47.1%(40/85) vs 50.7%(280/552), p=0.526, respectively. Logistic regression analysis revealed that the female age (p = 0.008, OR=0.942, 95% CI = 0.902-0.984) and embryo quality (ref: good quality for moderate: p=0.02, OR=0.469, 95% CI =0.269-0.760; for poor: p=0.013, OR= 0.269, 95% CI = 0.092-0.757) were independent variables for live birth. Following rescue protocol implementation, ET-day P concentration was not a significant predictor of live birth. Rescue vaginal P administration for low ET day serum P concentrations following IM-P yields comparable live birth rates.

Analysis of stressoprotective properties of progesterone on an animal model of post­traumatic stress disorder

Relevance. Sex steroid hormones play a fundamental role not only in reproductive biology, regulation of emotions and mood, but also participate in maintaining proper ho-meostasis of the nervous system, acting as trophic factors and neurotransmitters, while steroids are also synthesized de novo in both central and peripheral nervous system. One of the main neurosteroids is progesterone, and its two important metabolites, namely allopregnanolone (3a,5a-tetrahydroP4) and 3a,5a-tetrahydrodeoxycorti-costerone, which due to a combination of genomic and non-genomic effects, have a wide range impact on neural cells. Aim. To analyze the stress-protective properties of progesterone on an animal model of post-traumatic stress disorder. Materials and methods. 40 white mongrel male rats were taken for the purpose of investigation. They were divided into several investigation groups: Con — group of animals receiving intraperitoneal injection of solvent (n=10); PS — group of animals exposed to vital stress (n=10); PS+P — a group of animals exposed to vital stress and receiving an intraperitoneal oil solution of progeste-rone in a dose of 8 mg/kg (n=10) for 10 days before a stress exposure; PS+S — a group of animals exposed to vital stress receiving an intraperitoneal solution of sulpir-ide in a dose of 10 mg/kg (n=10). To simulate a psycho-traumatic event, the classical method of imaging a pred-ator was used. To record the changes in emotional-motor patterns among the control and experimental groups a battery of behavioral tests was used, Elevated Cruciform Maze, Open Field, and Porsolt test. Results. Changes in behavioral patterns were observed after administration of progesterone to animals that had been exposed to a psychotraumatic event. The impact on the “emotionali-ty” zone was characterized by a reliable increase in the number of sniffing (p≤0.05), and a significant increase of locomotor activity was also observed (p≤0.05). In the Ele-vated Cruciform Maze test, the anxiolytic effect of proges-terone was demonstrated, which consisted of a decrease in the time experimental animals spent in the closed arm of the installation and, accordingly, of an increase in the time ani mals stay in the open arm, which may indicate a decrease in the level of anxiety. Porsolt test demon-strates that the antidepressant effect of progesterone is to normalize the timing of behavioral patterns in animals exposed to a stressor. Conclusion. As a whole, the results of our study demonstrate that intraperitoneal administra-tion of an oily progesterone solution at a dose of 8 mg/kg has pronounced anxiolytic and antidepressant effects according to the results of a series of behavioral tests in the predator presentation stress model

982 Maternal and neonatal outcomes associated with route of progesterone administration in frozen embryo transfers

982 Maternal and neonatal outcomes associated with route of progesterone administration in frozen embryo transfers

A Single Administration of Progesterone during the Neonatal Period Shows No Structural Changes in Male Reproductive Tracts in Mice.

The concentration of female-dominant steroid hormones, such as progesterone and estrogen, drops after birth in neonates. We have reported that neonatal estrogen treatment results in inflammation in the epididymis after puberty in male mice. Our recent study discovered that progesterone receptor was specifically expressed in efferent ducts just before birth in male mice. Therefore, this study aimed to reveal the impact of neonatal progesterone administration on the efferent ducts after puberty. Progesterone was subcutaneously administered to neonatal mice on their birthday in three groups: high-dose (200 mg/kg), low-dose (8 mg/kg), and control (cottonseed oil). Their testis and epididymis were collected at 12 weeks old. Semi-serial paraffin sections of these tissues were prepared and evaluated through PAS-hematoxylin staining. Efferent ducts were reconstructed into a three-dimensional structure, and their length and volume were analyzed. Spermatogenesis in the testis and epithelium of the tracts appeared normal, even in individuals administered with progesterone. There were no significant differences in the length and volume of the efferent ducts among the three groups. This study suggests that progesterone treatment in neonatal mice does not cause any structural changes in the male reproductive tracts at puberty, unlike the neonatal estrogen treatment.

Phase-specific differential regulation of mechanical allodynia in a murine model of neuropathic pain by progesterone.

Progesterone has been shown to have neuroprotective capabilities against a wide range of nervous system injuries, however there are negative clinical studies that have failed to demonstrate positive effects of progesterone therapy. Specifically, we looked into whether progesterone receptors or its metabolizing enzymes, cytochrome P450c17 and 5α-reductase, are involved in the effects of progesterone on neuropathic pain after chronic constriction injury (CCI) of the sciatic nerve in mice. Intrathecal progesterone administration during the induction phase of chronic pain enhanced mechanical allodynia development and spinal glial fibrillary acidic protein (GFAP) expression, and this enhancement was inhibited by administration of ketoconazole, a P450c17 inhibitor, but not finasteride, a 5α-reductase inhibitor. Furthermore, phospho-serine levels of P450c17 in the spinal cord were elevated on day 1 after CCI operation, but not on day 17. In contrast, intrathecal progesterone administration during the maintenance phase of chronic pain decreased the acquired pain and elevated GFAP expression; this inhibition was restored by finasteride administration, but not by ketoconazole. The modification of mechanical allodynia brought on by progesterone in CCI mice was unaffected by the administration of mifepristone, a progesterone receptor antagonist. Collectively, these findings imply that progesterone suppresses spinal astrocyte activation via 5α-reductase activity during the maintenance phase of chronic pain and has an analgesic impact on the mechanical allodynia associated with the growing neuropathy. Progesterone, however, stimulates spinal astrocytes during the induction stage of peripheral neuropathy and boosts the allodynic impact caused by CCI through early spinal P450c17 activation.

Prelimbic and infralimbic responsivity to amygdala input is modified by gonadal hormones in parallel to low anxiety-like behavior in ovariectomized rats

Gonadal hormones may influence sexual activity by reducing anxiety. The basolateral amygdala (BLA) and prelimbic (PL) and infralimbic (IL) cortical regions comprise a loop that is related to fear, anxiety, and social behavior. In female ovariectomized rats, actions of estradiol, progesterone, and sequential estradiol and progesterone administration were explored in the open field test (OFT) and plus maze test (PMT) to evaluate signs of anxiety-like behavior. The three hormonal treatments reduced indicators of anxiety in the PMT but did not influence behavior in the OFT. In the same behaviorally tested rats under urethane anesthesia, single-unit extracellular recordings were obtained from the PL and IL during electrical stimulation of the BLA. The analysis of 250 ms peristimulus histograms showed that BLA stimulation produced two kinds of response. A small group of neurons increased their firing rate after BLA stimulation. Most neurons exhibited a reduction of spiking. Neurons that increased their firing rate after BLA stimulation did not show any difference with the hormonal treatments. In neurons that were inhibited by BLA stimulation, estradiol reduced the neuronal firing rate in the PL and IL, and progesterone alone and the sequential administration of estradiol followed by progesterone administration 24 h later (priming) increased the firing rate during the 240 ms before BLA stimulation. Analyses of responsivity of the PL and IL during electrical stimulation of the BLA indicated that estradiol, progesterone, and estradiol followed by progesterone administration 24 h later (priming) reduced inhibitory actions of the BLA on the PL but not IL. In the BLA-IL connection, progesterone exacerbated the inhibitory response. These findings indicate that anxiolytic actions of estradiol, progesterone, and estradiol followed by progesterone administration 24 h later (priming) correspond to lower BLA-PL responsivity. Actions of progesterone on BLA-IL responsivity appear to contribute to sexual activity by interacting with other forebrain structures that are also related to sexual receptivity.

#212 : Does Hyaluronic Acid-Containing Transfer Media Improve the Live Birth Rate in Frozen Embryo Transfer Cycles?

Background and Aims: The glue is typically composed of hyaluronan, a natural substance found in the female reproductive tract, and other nutrients that help to support the embryo. The glue is believed to improve the chances of successful implantation by helping the embryo adhere to the uterine lining and promoting communication between the embryo and the uterine environment. The effectiveness of embryo glue is still being studied, and limited evidence on its benefits is available. The objective of our study is to find the effect of hyaluronidase containing transfer media (Embryo Glue) on ART outcomes. Method: This retrospective study is based on central hospital recorded data between January 2015 and January 2022. The females aged 20-40 years and Body mass index (BMI) of 18.0 to 35 kg/m2 were included. Results: Univariate logistic regression showed that the duration of progesterone administration on (6-Days vs 7-days (OR 1.693; (1.045-2.740); P = 0.032), endometrial thickness on the day of P start (OR 1.167; (1.056-1.290); P = 0.002), Embryo Glue (ref. Standard treatment) (OR 1.700; 95% (1.364-2.118); P&lt;0.001) were independent factors for predicting live birth. Multivariate logistic regression analysis showed that female age (OR 0.927; (0.893-0.963) P &lt; 0.001), Number of blastocysts transferred (DET), (ref. SET) (OR 1.618; (1.086-2.410); P = 0.018), Endometrial thickness at the day of P start (OR 1.147; (1.014-1.298); P = 0.029) and Embryo Glue (ref. Standard treatment) (OR 1.593; (1.170-2.168); P = 0.003) were independent factors for predicting live birth. Conclusion: Embryo glue has shown significant outcomes in the present study and effectively improves IVF success and implantation rates. However, the decision to use embryo glue should be made on a case-by-case basis in consultation with a fertility specialist, and it may not be necessary or beneficial for all IVF procedures.