Luteinizing hormone (LH) and follicle-stimulating hormone (FSH), critical for reproduction, are heterodimers of a common α subunit and unique β subunits, that are limiting components in the mature hormone synthesis. GnRH from the hypothalamus regulates synthesis of LH and FSH β-subunits. Previous studies identified signaling pathways and transcription factors that mediate GnRH induction of β-subunits. However, these studies do not fully explain gonadotrope responsiveness to GnRH or mechanisms of how a single hormone can regulate two β-subunits differentially. We postulated additional transcription factors, coactivators or corepressors, that are awaiting identification. To provide novel candidates, we used discovery proteomics of protein complexes that associate with gonadotropin β promoters regions that contain GnRH-responsive elements, and protein complexes that interact with transcription factors that are activated by GnRH to induce gonadotropin β genes. Data are available via ProteomeXchange with identifier PXD075636. Using computational tools, such as Intervene and Tidyproteomics, we compare and contrast proteins in complexes to identify coactivators or corepressors that may be unique or in common for both gonadotropin β subunit transcriptional upregulation or repression, novel transcription factors, and proteins that may regulate both gonadotropin β gene expression, proteins specific to each promoter, and proteins that are recruited via interaction with intermediate GnRH-induced transcription factors. Our studies can serve as a resource to interrogate potential candidates in cell cultures and in vivo for their roles in gonadotropin β expression. Understanding the mechanisms whereby GnRH regulates gonadotropin hormone levels will provide insight into the physiology and pathophysiology of the reproductive system.

This study aimed to evaluate the effects of equine chorionic gonadotropin (eCG), Estradiol benzoate (EB) and Gonadotropin-releasing hormone (GnRH) on follicular dynamics and luteal characteristics of buffaloes (Bubalus bubalis). The animals were separated into four experimental groups: EB (n=10), EB+eCG (n=10), GnRH (n=10) and GnRH+eCG (n=10). Using B-mode and Power-Doppler ultrasound, follicular characteristics of the largest follicle, from day 9 until day 11, diameter of the preovulatory follicle, follicular area, total wall area of the preovulatory follicle, growth rate of the ovulatory follicle, vascularization in the wall area of the preovulatory follicle, percentage of vascularization in the wall area of the preovulatory follicle and moment of ovulation, were evaluated for follicular dynamics. Furthermore, on day 18 of the protocol, diameter of the corpus luteum, total area of the corpus luteum, vascularization of the corpus luteum, percentage of vascularization of the corpus luteum and the serum progesterone levels were also evaluated. Statistical analyses were performed using Tukey's test, Kruskal-Wallis and repeated measures ANOVA with a 5% significance level. Statistically significant differences were found for diameter of the corpus luteum with 1.78±0.12cm in the EB+eCG group and 1.62±0.11cm in the EB group (p=0.047), as well as in the Progesterone dosages between the treatments GnRH+eCG (4.09±0.94ng/mL) and GnRH (2.80±0.70ng/mL), p=0.017. Regarding the variables assessed by Power Doppler, no statistical differences were found between the experimental groups. Finally, the price analysis revealed that the EB+eCG protocol is 19% cheaper than the GnRH+eCG protocol. Therefore, EB offers better cost/benefit on the reproductive parameters of buffaloes subjected to pharmacological control of the estrous cycle.

Chimeras (Holocephali) occupy a pivotal phylogenetic position, being the oldest jawed vertebrate, for understanding the evolution of hypothalamic-pituitary organization in vertebrates. However, the structural organization of the hypothalamic-pituitary axis and the anatomical relationships with the buccal lobe (BL), a unique gland thought to play a role in reproduction, remains poorly characterized. We present an anatomo-histological analysis of the chimaera Callorhinchus callorynchus using classical histology, immunohistochemistry, and RT-PCR, focus on key neuropeptides related to the control of the reproductive activity in other vertebrates: gonadotropin-releasing hormone (GnRH), secretoneurin (SN), cholecystokinin (CCK), and gonadotropic hormones. The pituitary gland displays clear regionalization into the rostral pars distalis, proximal pars distalis, and neurointermediate lobe. The BL is connected to the posterior telencephalon by paired canals containing a prominent blood vessel and bundles of neuropeptidergic fibers. Gonadotropin-releasing hormone-immunoreactive nerve cell bodies and fibers were identified in the posterior telencephalon using two antisera, with fibers projecting to the proximal pars distalis of the pituitary and the BL. Secretoneurin-immunoreactive neuronal somata and fibers were observed in the posterior telencephalon and hypothalamus, and SN-immunoreactive cells were also present within the pituitary and BL. Cholecystokinin-immunoreactive neuronal elements were detected in the hypothalamus, while CCK-immunoreactive cells were present in the pituitary, and a subset of fibers extending into the BL. RT-PCR analyses revealed the presence of Fshb and Fhb transcripts in the pituitary and BL, with a stronger apparent signal in the BL. These observations provide anatomical evidence for direct neuropeptidergic innervation of both the pituitary and BL and indicate that the BL is associated with gonadotropin subunit gene expression in C. callorynchus. This new anatomical framework of the hypothalamus-pituitary-BL axis identifies two new pathways: direct GnRH and CCK innervation, and local SN-mediated autocrine/paracrine signaling.

Disorders of gonadotropin pulsatility contribute to reproductive dysfunction in humans and are often associated with metabolic dysfunction. Hypogonadotropic hypogonadism is characterized by chronically insufficient gonadotropin hormone production, leading to reproductive and metabolic impairments, such as infertility and obesity. Polycystic ovary syndrome (PCOS) is characterized by accelerated gonadotropin hormone production leading to reproductive and metabolic deficits, including oligomenorrhea, infertility, and an increased risk of type 2 diabetes mellitus. Hypothalamic kisspeptin is a key regulator of gonadotropin secretion, and disruptions in kisspeptin signaling result in abnormal gonadotropin pulsatility. Emerging evidence also implicates kisspeptin in energy metabolism. This study investigates the neuroendocrine mechanisms by which kisspeptin within KNDy neurons influences metabolic homeostasis. Using a Pdyn-Cre/Kiss1fl/fl knock-out (Kiss1Pdyn KO) mouse model, we combined diet-induced obesity, metabolic testing, and ovarian hormone depletion to assess the role of KNDy neuron kisspeptin in metabolic regulation and the interaction with sex steroids. Peripheral metabolism was more severely impacted in Kiss1Pdyn KO females than in KO males, with greater reproductive deficits observed in females. Abnormal glucose metabolism was partly attributable to the lack of ovarian steroids. Our findings indicate that loss of KNDy neuron kisspeptin in females promotes obesity through reduced energy expenditure without altering feeding behavior. Furthermore, this study identifies a female-biased role for KNDy kisspeptin as a central integrator of reproductive and metabolic signals.

Selenium (Se) is a novel addition to in vitro maturation (IVM) media, unlike the traditional gonadotropin hormone. This highlights the advancements in reproductive biology and potential strategies to enhance oocyte maturation. This research was conducted to determine the effect of Se and gonadotropin hormone supplementation into maturation medium on the in vitro oocyte maturation of Bligon goat. Ovaries from Bligon goats were obtained from a slaughterhouse in Special Region of Yogyakarta. High-quality oocytes (grades A and B) were retrieved through aspiration, washed, and cultured in medium beneath mineral oil. Three experimental conditions were established: 50 μL of unsupplemented medium (T0), 48 μL of medium + 2 μL of gonadotropin (T1), and 48 μL of medium + 2 μL of Se (T2). The culture process was conducted for 24 h at 39°C, 95% humidity, and 5% CO2. Oocyte maturation was evaluated based on cumulus cell expansion, and the data obtained were analyzed using One-Way ANOVA, followed by Tukey’s Post Hoc test. The results indicated that the inclusion of either Se (86.26±7.20%) or gonadotropin (88.13±7.85%) in the IVM medium significantly enhanced (p<0.05) the maturation rate compared with that of the unsupplemented group (50.09±11.90%). However, there was no significant difference (p>0.05) between the two supplements. In conclusion, both Se and gonadotropin hormones proved to be effective supplements for improving the maturation rate of Bligon goat oocytes.

ABSTRACTBackgroundGonadotropins are glycoprotein hormones that are often secreted from the gonadotrope cells of the pituitary gland. These hormones play an essential role in growth, reproduction and sexual function.AimsTherefore, this research was conducted to identify genetic polymorphisms of the Gonadotropin‐Releasing Hormone Receptor (GnRHR) gene on Isfahan native hen traits and their relationship with production traits.Materials & methodsFor this purpose, blood was taken from 100 Isfahan native hens that were randomly selected from the Isfahan native hen centre. DNA was extracted by the phenol‐chloroform method. Then, using the designed primers, the target fragment was amplified and directly sequenced. The sequences were blasted with the reference gene in NCBI. After analysing the sequences, the relationship between genotypes and traits was investigated.ResultsThe results showed that five single‐nucleotide polymorphisms in gene GNRHR were observed. These polymorphisms were located in nucleotides numbers 117, 123, 157, 453 and 550 of the amplified fragments and caused the change of nucleotide T to C, C to T, C to T, C to T and A to G, respectively. According to the results, the GnRHR gene has an acceptable effect on the productive traits of Isfahan native hens. Of course, its effect cannot be considered important for the entire production traits, but in the sexual maturity sections, the number of eggs plays an important role and has a significant effect on the mentioned production traits.ConclusionThese results show that the observed nucleotide changes if confirmed in other relevant studies can be used in the trait selection programme with the help of markers.

This research presents the design and modeling of a novel multifunctional plasmonic optical nanosensor for the early diagnosis of pregnancy using urine samples. The sensor features a unique architecture based on a ring resonator supercell, which generates three distinct resonance modes in the near-infrared spectrum. A key innovation is that each resonance mode operates independently, effectively tripling the device's data acquisition capability from a single measurement. The operational principle relies on detecting minute changes in the refractive index of urine caused by varying concentrations of the human chorionic gonadotropin hormone. Through rigorous simulation using the Finite-Difference Time-Domain method, the sensor demonstrates high performance, achieving a maximum sensitivity of 891.36nm/RIU and a superior figure of merit of 21.26 RIU⁻1. The study concludes that this robust, multimode platform holds significant potential for highly sensitive, non-invasive, and early-stage biomedical diagnostics.

HIF-2α expression is controlled by the progesterone receptor and regulates hCG-induced gene expression in granulosa cells during ovulation in mice.

Testicular cancer primarily affects men of reproductive age. Therefore, fertility preservation is important in managing testicular cancer. In patients with a solitary testis, oncological testicular sperm extraction (onco-TESE) is used to retrieve sperm from tumor-bearing testis. A 39-year-old man with congenital absence of the left testis presented with a 4-month history of progressive right testicular swelling. Laboratory tests showed elevated β-human chorionic gonadotropin and follicle-stimulating hormone concentrations, and ultrasonography showed a heterogeneous hypoechoic mass with microcalcifications. A seminal analysis showed azoospermia with AZFc partial deletion. Following orchiectomy, microsurgical onco-TESE was performed. Motile sperm were successfully retrieved from preserved seminiferous tubules. A pathological examination demonstrated a pure seminoma. In preserved seminiferous tubules, the Johnsen score was 9-10, andpartial tubular hyalinization and microcalcifications were observed. Microsurgical onco-TESE is for retrieving sperm in patients with testicular cancer with a solitary testis, even in the presence of impaired spermatogenesis.

This study examined the effect of Vitamin E and Selenium, compared to equine chorionic gonadotropin (eCG), on the fertility of synchronized ewes as measured by ultrasonography. The objective of this study was to use ultrasound to assess the effects of Vitamin E and Selenium compared with those of equine chorionic gonadotropin (eCG) on the reproductive performance in synchronized ewes. The aim of the study was to increase fertility or the proportion of multiple pregnancies and to compare the effects of either hormonal (eCG) or nutritional supplementation (Vitamin E and Selenium) following estrus synchronization. We used 15 healthy adult ewes, aged 2-4 years. They were divided into three groups (5 ewes in each group). The ewes were synchronized using intracervical progesterone-impregnated sponges (Chronogest CR) for 14 days. Following sponge removal, ewes in the first group were used as untreated controls, ewes in the second group were given an intramuscular injection of 500 IU eCG, and ewes in the third group were given an intramuscular injection of 5 ml of Vitamin E and Selenium. Estrus response was evaluated 24-48 hours after sponges were removed, and pregnancy was diagnosed by transabdominal ultrasonography using a 3.5-7.5 MHz probe. It was found that the estrus response was 100% in all groups. The pregnancy, lambing, and fertility rates for the control group were 60%, with a multiple lambing rate of 20%. In the eCG-treated group, pregnancy, lambing, and fertility rates increased to 80%, with a multiple lambing rate of 60%. The best reproductive performance was observed in the group treated with Vitamin E and Selenium, where pregnancy, lambing, and fertility rates reached 100%, while the multiple lambing rate was 40%. Ultrasonographic examination also demonstrated a progressive increase in gestational sac size and uterine diameter during early pregnancy. In conclusion, the findings suggest that the use of Vitamin E and Selenium after estrus synchronization may enhance reproductive performance and improve pregnancy outcomes in ewes. Transabdominal ultrasonography was also found to be useful in early pregnancy diagnosis, as well as for tracking conceptus growth in ewes.

To study the effect of low-estrogen and the menopause state upon female pituitary function, we used the 4-vinylcyclohexene diepoxide (VCD)-induced ovarian failure model to gradually reduce serum estradiol (E2) levels. We utilized single-cell RNA sequencing transcriptomics analysis (scRNA-seq) to determine how reduced E2 levels influence pituitary gonadotrope gene expression and cell state, with a focus on potential contributions from pituitary stem cells to gonadotrope population growth. VCD-treated mice were acyclic and exhibited 8-15-fold increases in serum levels of the gonadotropins follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Serum E2 levels were half those of normally cycling proestrous females. Pituitary scRNA-seq identified two gonadotrope populations based upon distinct gene expression signatures (a higher cell number primary cluster, designated here as GON1 and a smaller cell number secondary cluster, designated GON2). The GON1 population increased in number significantly in low-E2, VCD-treated mice, expressing markers indicative of contributions from pituitary stem cell activation. Both gonadotrope populations showed upregulated genes for canonical pathways supporting mRNA translation and hormone secretion, which correlated well with the high serum gonadotropin levels. Consistent with the high serum gonadotropin levels, Fshb and Lhb mRNAs were increased in whole pituitary samples (RT-qPCR). The pituitary Sox2-positive stem cell population exhibited increased expression of more mature transitional progenitors, including Sox9 mRNA, and showed upregulation of pathways involved in stem cell development and mitotic activity. This model provides insight into the cellular and molecular adaptations of the pituitary to the low-E2, menopausal state, with potential relevance for understanding human perimenopausal and menopausal physiology.

Diabetes mellitus (DM) is a metabolic disorder that impairs the body's ability to regulate blood sugar levels, leading to cellular damage and apoptosis. Metformin (Met) and glutathione (GSH) are key antioxidants that prevent damage to mitochondrial DNA and proteins by modulating oxidative stress in testicular cells. This study assessed concomitant therapy with GSH and Met to mitigate testicular apoptosis in diabetic male mice. Six- to eight-week-old male BALB/c mice were randomly divided into four groups (n=6): DM control, DM+Met (200mg/kg), DM+GSH (15mg/kg), and DM+Met (200mg/kg)+GSH (15mg/kg). Diabetes was induced by i.p. injection of 50mg/kg body weight (BW) streptozotocin for five consecutive days. The DM control group served as a baseline to evaluate the effects of treatments. GSH was administered weekly (i.p.), and Met was administered orally daily for 35 consecutive days. BW and fasting blood glucose levels were monitored on Day 0 and Day 44. The fasting blood glucose levels were reduced (P<0.05, P<0.01, P<0.001) while BW, the number of Bax-positive cells, Bax mRNA expression, and Bax : Bcl-2 ratio were restored in all treatment groups (P<0.05, P<0.01, P<0.001). In contrast, FSH, LH, testosterone, the number of Bcl-2 positive cells, Bcl-2 mRNA expression, and mitochondrial genes were increased in all treatment groups (P<0.05, P<0.01, P<0.001). These findings suggest that GSH combined with Met restores apoptotic and mitochondrial dynamics, potentially mitigating diabetes-associated testicular damage by modulating the expression of genes involved in apoptotic and mitochondrial processes, thus positioning GSH as a promising complementary therapy. Combined GSH and Met therapy may offer a novel synergistic strategy to protect male fertility in diabetes condition by targeting cellular stress pathways. Further studies are warranted to translate these findings into clinical applications.

Activin-class ligands of the transforming growth factor β family induce follicle-stimulating hormone (FSH) production by pituitary gonadotrope cells in mice via the actions of the transcription factors SMAD3, SMAD4, and FOXL2, which bind to cis-elements in the FSHβ subunit (Fshb) promoter. An enhancer region for murine Fshb transcription was identified in vitro. However, deletion of the region using CRISPR-Cas9 did not affect FSH synthesis or secretion in mice. Using single-nucleus ATAC-seq of whole murine pituitaries, we identified 3 additional open chromatin regions upstream of Fshb exclusively in gonadotropes. These regions, as well as the Fshb gene, were fully or partially closed in gonadotropes of FSH-deficient mice with genetically or pharmacologically inactivated activin type II receptors. The initially characterized enhancer region did not significantly alter basal or activin-stimulated murine Fshb promoter-reporter activity in homologous LβT2 cells. In contrast, the other 3 open chromatin regions enhanced basal and activin A-stimulated Fshb promoter-reporter activity in LβT2 cells, with the 2 most distal showing the greatest effects. These 2 regions were open, exhibited enrichment of the enhancer mark H3K27ac, and were bound by SMAD2/3 and FOXL2 in response to activin A in LβT2 cells. The most distal enhancer exhibited strong FOXL2 and weak SMAD4 binding in gel shift assays. SMAD4, but not FOXL2, directly bound the other distal enhancer. Mutation of defined FOXL2 and SMAD4 cis-elements diminished enhancer activity in reporter assays in LβT2 cells. Collectively, the data indicate that there may be as many as 4 activin-sensitive enhancers upstream of murine Fshb.

A large "gene desert" located far upstream from Fshb and Kcna4 contains several gonadotrope-specific accessible chromatin sites that were seen in chromatin conformation capture to make distinct contacts with both genes. Expression of Fshb and Kcna4 was strongly inhibited by JQ-1, which represses super-enhancer activity, and the region displays super-enhancer characteristics. The sites of open chromatin were seen, in chromatin immunoprecipitation, to bind Brd4 and Med1, most notably at a site -67 kb from the Fshb gene, as well as binding Ctcf further upstream (-123 kb), all of which were increased following activin exposure. The locus is transcribed to chromatin-associated long noncoding RNAs whose levels correlate with Fshb and Kcna4 mRNA levels in vivo and in cultured gonadotrope cells, indicating coordinated regulation. CRISPR interference confirmed distinct functions for each element and, together with the chromatin conformation capture data, indicate that the -67 kb locus mediates basal and activin-stimulated Fshb expression, whereas the site at -59 kb contributes to activin-stimulation of both genes. Single-cell multiomics revealed that the -67 kb locus is accessible in pituitary stem cells and throughout gonadotrope differentiation, preceding opening of the Fshb promoter, although it is closed in other differentiated cell types, suggesting a gonadotrope-specific factor that keeps it open at this stage. Foxl2 was found to bind this element, contributes to maintaining its chromatin accessibility, and recruits Supt16h, a component of the Facilitates Active Chromatin Transcription histone chaperone complex. These findings define a distal, Foxl2-bound super-enhancer that regulates Fshb transcription and shapes the gonadotrope regulatory landscape.

Hormonal actions of relaxin-like gonad-stimulating peptide in starfish.

Male hypogonadotropic hypogonadism is characterized by deficient secretion of luteinizing hormone and follicle-stimulating hormone, leading to low testosterone levels, impaired spermatogenesis, and often infertility. Treatment aims to normalize testosterone and induce spermatogenesis, with gonadotropin therapy as standard. Factors affecting treatment success and optimal duration remain unclear. This single-center retrospective cohort study assessed the outcomes of gonadotropin therapy in men with hypogonadotropic hypogonadism and azoospermia. Men ≥ 18 years were included. The primary outcome was the successful induction of spermatogenesis. Data on demographics, treatment regimens, semen parameters, pregnancy outcomes, and side effects were collected. Regression analyses identified factors associated with treatment success. Thirty-five men were included. Spermatogenesis was achieved in 74% of patients, with higher success rates in those receiving combined human chorionic gonadotropin and follicle-stimulating hormone therapy (78%) versus human chorionic gonadotropin monotherapy (33%). Of those producing sperm, 69% upgraded to a higher WHO semen category, with 29% reaching normospermia. The median maximum sperm concentration achieved during treatment was 8.3 million/mL (IQR: 1.9-36.3). A larger baseline testicular volume was associated with a higher success rate of spermatogenesis and a shorter time to pregnancy. Pregnancy was achieved in 68% of patients, with 39% through spontaneous conception. The median time to first spermatogenesis was 7 months and to pregnancy was 21 months. Mild side effects occurred in 16% of patients. Gonadotropin therapy is effective and well tolerated in inducing spermatogenesis and achieving pregnancy in azoospermic men with HH. These findings, based on a contemporary Western cohort, provide updated evidence that supports personalized counseling and underscore the importance of long-term treatment adherence for successful fertility restoration. Some men are infertile because their brain does not produce the hormones needed to make sperm. This condition is called hypogonadotropic hypogonadism. These men often have low testosterone and no sperm in their semen. In this study, we looked at whether hormone treatment could help these men produce sperm and have children. We studied 35 men who were given hormone injections at a Dutch university hospital. After treatment, 74% of them started producing sperm. Those who received a combination of two hormones had better results than those who received only one. Almost 70% of men with sperm had better sperm quality, and over a quarter reached normal sperm levels. Two-thirds of men who wanted children became fathers, mostly through natural conception. Our findings show that hormone treatment is safe and often successful. This can offer hope to men with this condition who want to become fathers.

Photoperiod effects on the expression of deep brain photoreceptors and gonadotrophin genes are sex- and age-dependent in Pekin ducks.

Serotonin neurons are thought to exert a modulatory influence on the secretion of the gonadotropin hormones in mammals, but their mechanism of action remains unclear. We examined here the potential role of serotonin neurons in modulating the activity of the gonadotropin-releasing hormone (GnRH) pulse generator formed by the arcuate nucleus kisspeptin (ARNKISS) neurons. Acute brain slice electrophysiology revealed that ∼60% of ARNKISS neurons in diestrous female mice were activated by serotonin while less than 10% were inhibited. Pharmacological studies indicated that combinatorial patterns of 5-HT receptor subtype activation were likely responsible for the excitatory actions. The role of serotonin in ARNKISS neuron synchronization behavior was assessed using GCaMP imaging in acute brain slices from diestrous female and male mice. In both sexes, serotonin-evoked potent recurring bouts of synchronization activity amongst ARNKISS neurons. To evaluate the impact of serotonin in vivo, we used "fluidic" GCaMP fiber photometry in which serotonin was infused directly into the ARN while recording the ARNKISS neuron population activity in freely behaving diestrous female mice. In all cases, the infusion of serotonin evoked a robust ARNKISS neuron synchronization episode. These data demonstrate that serotonin exerts a direct, predominantly stimulatory action on ARNKISS neuron pulse generator through a variety of 5-HT receptors. Serotonergic inputs appear to provide a potent synchronizing influence on the ARNKISS neuron population and suggest considerable potential for 5-HT to control the frequency of pulsatile reproductive hormone secretion in mice and likely other mammals.

Background: Severe acute respiratory syndrome coronavirus 2 (COVID-19) can result in systemic inflammatory reactions that could disrupt endocrine and placental physiology in the course of pregnancy. The presence of the key pregnancy-supportive hormones, which are critical to keep the gestation and placental activity, includes progesterone, estradiol, and 2-human chorionic gonadotropin (2-hCG), whereas cortisol and thyroid-stimulating hormone (TSH) indicates the maternal stress and thyroid-regulatory pathways. Although the evidence of COVID-19-induced changes in physiological changes is accumulating, the impact of severe infection on maternal hormonal profiles during pregnancy is not defined well enough. Aim: This research was meant to assess the effect of severe COVID-19 on chosen maternal hormonal parameters in second-trimester pregnant women. Methods: The study was a hospital-based case-control study carried out at Al -Nasiriyah Teaching Hospital in Dhi Qar Province in the year 2020. It involved 200 pregnant women between the ages of 25 and 40 years with a gestation period of 1620 weeks. The sample was split into two groups of which 100 women were confirmed to have severe COVID-19 that needed oxygen therapy and 100 healthy pregnant controls. Each of the participants was a singleton, with comparable body weight (73 75 kg), and chronic disease or thyroid disorders were excluded. Blood samples were taken to the venous blood used to measure serum progesterone, estradiol (E2), 8-hcg, cortisol and TSH concentrations in the serum by the use of enzyme linked immunosorbent assay (Elisa) kit. The levels of hormones in the infected group were measured about one month after infection and statistical comparisons with the appropriate parametric or non-parametric tests were conducted on the levels. Results: The women with the worst cases of COVID-19 had much lower progesterone, estradiol and 2-hCG levels than the controls. On the other hand, the levels of cortisol were dramatically increased in the infected group, whereas the levels of TSH have decreased slightly but significantly. Conclusions: Major endocrine changes in severe COVID-19 in the second trimester comprise low placental hormones, high cortisol, and low TSH. These results indicate possible effects of a serious case of viral infection on placental endocrine functions and maternal stress mechanisms, and hormonal surveillance of such pregnancies is critical.

Serum beta-human chorionic gonadotropin (β-hCG) hormone is a well-established biomarker used for pregnancy monitoring and prognosis in in vitro fertilization (IVF) cycles. After embryo transfer, a high serum β-hCG level with a prompt doubling time is typically reassuring, while a low initial β-hCG often leads to counselling around likely impending pregnancy loss and/or ectopic pregnancy. However, the number of patients with low β-hCG who ultimately deliver a live birth is unclear. This is a single-centre retrospective cohort study of IVF pregnancies between January 2019 and December 2022. Serum β-hCG was drawn 14 days post-fertilization. We considered an initial β-hCG ≤ 50 mIU/mL as low. A logistic mixed-effects regression model assessed the odds of live birth for every 10 mIU/mL increase in β-hCG, adjusting for patient and cycle characteristics (age, body mass index, embryo stage, number of embryos transferred, and preimplantation genetic testing for aneuploidy). Receiver operating characteristic curves were plotted to determine optimal cut-points. Among 2443 pregnancies, the prevalence of live birth was 12% for those with an initial β-hCG ≤ 50 mIU/mL. For each 10 mIU/mL difference in initial β-hCG, the odds of live birth increased significantly (aOR = 1.035 [95% CI 1.027, 1.042]). Receiver operating characteristic curve analysis showed that an initial β-hCG greater than 22.5 mIU/mL identified over 99% of patients who ultimately had a live birth (sensitivity 1, specificity 0.21, AUC 0.726). The rate of change from initial β-hCG demonstrated stronger discriminatory performance for live birth among patients with low initial β-hCG (AUC 0.876 [95% CI 0.84, 0.91]) than among those with an initial β-hCG > 50 mIU/mL (AUC 0.584 [95% CI 0.56, 0.61]). While IVF pregnancies with a low initial β-hCG can result in live birth, the likelihood is low. The rate of β-hCG rise emerged as a stronger discriminator of pregnancy outcomes when the initial β-hCG is low. Live birth was extremely rare when the initial β-hCG was below 22.5 mIU/mL. These findings offer prognostic data to guide counselling and refine expectations after IVF.