Search Results (413)

This study investigated the effects of letrozole (LE) on reproductive performance, hormones, and plasma metabolites in Turpan Black ewes. Sixty-six multiparous non-pregnant ewes were randomly assigned to a Control group or an LE group (0.2 mg/kg body weight, added to the basal diet) for 180 days, both receiving estrus synchronization. LE significantly increased the twinning rate (p < 0.05), but no significant differences were observed in estrus rate, conception rate, or lambing rate (p > 0.05). Hormone analysis revealed significant changes in Luteinizing Hormone (LH), Progesterone (P₄) (group, time, and interaction effects), Estradiol (E₂), Testosterone (T) (time effect), Gonadotropin-Releasing Hormone (GnRH) (group and interaction effects), and Follicle-Stimulating Hormone (FSH) (primarily time effect). Metabolomic analysis identified 3451 differential metabolites. L-saccharopine and 5-hydroxylysine were downregulated (p < 0.01), and estrone was decreased (p < 0.05). Lysylhistidine was upregulated (p < 0.05), while testosterone and LE showed rising trends without statistical significance (p > 0.05). These metabolites were mainly enriched in amino acid metabolism and lipid metabolism pathways related to reproduction. Significant correlations were also detected between several metabolites and reproductive hormones. LE improves the twinning rate in Turpan Black ewes, likely by modulating key reproductive hormones (LH, P₄, GnRH, FSH, E₂, T) and altering plasma metabolites involved in amino acid and lipid metabolism. These findings provide new insights into the regulatory mechanisms of letrozole on ovine reproduction. Full article

This experiment aimed to investigate the metabolism of L-Citrulline (L-Cit) in the intestinal tract of ewes and its effects on fecal microbiota composition, plasma metabolism, and reproductive hormone levels. Twelve 18-month-old non-pregnant multiparous Turpan black ewes weighing 51.65 kg ± 2.49 kg were selected and randomly assigned to a control group (Con) and an experimental group (L-Cit), with six ewes in each group. Both groups were fed identical nutrient-dense rations. In the Con group, 100 mL of saline was administered through the duodenal fistula, while the L-Cit group received an additional 0.25 g/kg BW⁻¹ of L-Cit solution. On day 7, the crude protein and amino acid concentrations in feces and urine were assessed using total feces and urine collection methods. Fecal and blood samples were collected to evaluate microbiological and reproductive hormone indices, with blood samples also collected for plasma non-targeted metabolomics analysis two hours post-infusion. Compared to the Con group, the L-Cit group exhibited a significant reduction in crude protein content in feces (p < 0.05) and a highly significant decrease in urine (p < 0.01). Nitrogen metabolism indices did not differ significantly between groups (p > 0.05), but the L-lysine content in feces was significantly higher in the L-Cit group (p < 0.05). 16S rRNA sequencing revealed no significant PCA separation between the two groups. However, the relative abundance of Lachnospiraceae_NK3A20_group, Oscillibacter, and Mogibacterium was significantly higher in the Con group (p < 0.01), while SP3-e08, Parvibacter, Anaerosporobacter, Butyricimonas, and Peptococcus were more abundant in the L-Cit group (p < 0.05). LC-MS analysis showed significant up-regulation of purine and nucleotide metabolism pathways in the L-Cit group (p < 0.05). Plasma levels of estradiol (E₂), progesterone (P₄), gonadotropin-releasing hormone (GnRH), follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were significantly elevated in the L-Cit group at both 1 and 2 h post-infusion (p < 0.01). These results suggest that duodenal infusion of L-Cit enhances intestinal nitrogen utilization, alters specific bacterial populations, promotes purine and nucleotide metabolism, and stimulates reproductive hormone secretion in ewes. Full article

Endometriosis is a long-term gynecological condition marked by the growth of endometrial-like tissue outside the uterus, which undergoes proliferation, bleeding, and regeneration. This disease is associated with disrupted steroid hormone signaling, notably progesterone (P4) resistance and estradiol (E2) dominance. P4 resistance has been associated with impaired activation of the progesterone receptor (PR) and reduced transcription of P4 target genes, while elevated E2 levels induce estrogen receptor (ER)-mediated signaling, enhancing estrogen-dependent lesion growth. This hormonal imbalance contributes to a pro-inflammatory microenvironment, chronic pelvic pain, infertility, and enhanced neuroangiogenesis. Emerging evidence indicates that the coordinated regulation of neurotrophins and sex hormones promotes nerve fibers and blood vessel growth and invasion within endometriotic lesions. P4 and E2 have been shown to modulate the expression of key neurotrophins, including nerve growth factor (NGF) and brain-derived neurotrophic factor (BDNF). This review presents current evidence on the interplay between neurotrophins and ovarian steroids in endometriosis, with a specific focus on their contribution to neuroangiogenesis and pain pathophysiology. The review includes articles in English containing the Medical Subject Headings (MeSH) terms: “endometriosis”, “neurotrophins”, “nerve growth factor”, “brain-derived neurotrophic factor”, “neuroangiogenesis”, “progesterone”, and “estradiol”, found in the PubMed database published between 2000 and 24 May 2026. This review included a range of original research articles, systematic reviews, meta-analyses, prospective observational studies, case–control studies, and review papers, for a total of 122 articles. Full article

Background/Objectives: Minipuberty represents the second phase of physiological activation of the reproductive axis and may play a role in postnatal genital development. Its course has been shown to be affected by untreated or inadequately treated maternal hypothyroidism. The aim of the present study was to investigate minipuberty in the sons of women with euthyroid autoimmune thyroiditis during pregnancy. Methods: This prospective matched cohort study included three groups of apparently healthy infant boys. Two groups comprised the male offspring of levothyroxine-naive, euthyroid women with autoimmune thyroiditis: one group was unsupplemented, and the other received vitamin D and selenium supplementation. The control group consisted of boys born to healthy women. Salivary concentrations of testosterone, androstenedione, DHEA-S, estradiol, and progesterone, along with urinary FSH and LH levels, were assessed longitudinally over the first 12 months of life. These hormonal measurements were evaluated in relation to genital development, including testicular volume and penile length, which were recorded at each study visit. Results: Compared with the offspring of healthy mothers, sons of women with autoimmune thyroiditis who did not receive supplementation exhibited lower concentrations of LH and testosterone, without a distinct peak, while the duration of hormone detectability did not differ between the groups. These hormonal alterations were accompanied by reduced penile length, with no differences observed in testicular volume. This group also exhibited lower DHEA-S concentrations, whereas levels of other hormones were comparable. In contrast, in the group receiving vitamin D and selenium supplementation, the dynamics of hormonal changes and genital organ growth did not differ from those observed in the control group. LH concentrations were inversely correlated with thyroid peroxidase antibody titers, which were lower in the supplemented group. Conclusions: The findings indicate an altered course of minipuberty in the sons of women with euthyroid autoimmune thyroiditis during pregnancy and suggest a potential benefit of exogenous vitamin D and selenium supplementation in this population. Full article

Background: Spermidine is involved in a wide range of cellular processes, including mammalian oocyte development. Wheat germ is a natural source of polyamines and contains high concentrations of spermidine. However, no studies have evaluated the effects of wheat germ-derived spermidine on the regulation of mammalian ovarian function. The present study aimed to investigate the effect and underlying mechanism of wheat germ-derived spermidine on mammalian ovarian function. Methods: A feeding trial was carried out on mice with diets supplemented with varying concentrations of spermidine. The underlying mechanism by which spermidine exerts its beneficial effects on ovarian function and fertility in mice was explored through the integration of serum metabolomics and intestinal microbiomics analyses. Results: The results showed that dietary spermidine-rich feed significantly increased spermidine absorption and affected the metabolism of spermine and putrescine in the intestines. Dietary intake of low-concentration spermidine significantly increased the number of pups per litter and the secretion levels of estradiol (E2), progesterone (P4), luteinizing hormone (LH), and anti-Müllerian hormone (AMH). Furthermore, compared with a normal diet, spermidine supplementation resulted in significantly higher ovarian reserves and fewer atretic follicles. Correspondingly, metabolomics analysis revealed that spermidine primarily affected lipid metabolism and endocrine functions related to reproduction. In addition, dietary spermidine significantly altered the structural composition of the gut microbiota. Correlation analysis demonstrated that the abundance of Oceanisphaera, Atopostipes, and Actinobacteriota was significantly positively correlated with the secretion of E2, P4, and LH. Conclusions: Overall, these findings yield phenotypic insights into spermidine’s mediation of mammalian reproductive performance and offer a potential therapeutic strategy for individuals with reproductive dysfunction. Full article

Background/Objectives: Minipuberty is a transient activation of the hypothalamic–pituitary–gonadal axis in infancy that contributes to the postnatal development of sexual organs. Its course has been shown to be influenced by maternal hypothyroidism. This study aimed to evaluate the reproductive axis and genital development in infant girls born to women with euthyroid autoimmune thyroiditis. Methods: The study involved three groups of infants: two groups were daughters of euthyroid women with autoimmune thyroiditis, while the third group (control) consisted of daughters of women without thyroid disease during pregnancy. Half of the mothers with thyroiditis received additional vitamin D and selenium supplementation during pregnancy, whereas the other half did not. During the first 18 months of life, periodic assessments were conducted of gonadotropin concentrations in urine, as well as salivary levels of estradiol, progesterone, testosterone, androstenedione, and DHEA-S. Additionally, ovarian volume, uterine length, and breast diameter were measured in the infants. Results: Daughters of women with autoimmune thyroiditis who did not receive supplementation during pregnancy exhibited lower levels of LH, estradiol, and progesterone, as well as a more rapid decline in LH and estradiol to below detectable levels, compared with daughters of healthy women. These hormonal differences were accompanied by smaller uterine length and breast diameter in this group. No differences were observed between the offspring of non-supplemented women with thyroiditis and daughters of healthy women regarding the levels of other hormones or ovarian volume. The dynamics of all assessed hormone levels and organ measurements did not differ between daughters of euthyroid women with thyroiditis who received vitamin D and selenium supplementation and daughters of healthy women. LH and progesterone levels showed inverse correlations with anti-thyroid peroxidase antibody titers, whereas uterine and breast dimensions positively correlated with estradiol levels. Conclusions: These findings suggest that maternal euthyroid autoimmune thyroiditis can affect the progression of female minipuberty, while supplementation with vitamin D and selenium during pregnancy may mitigate this effect. Full article

Silicon (Si) is an essential trace element involved in multiple physiological processes of animals. This study aimed to investigate the dose-dependent effects of dietary silica (SiO₂) supplementation on production performance and key blood parameters in laying hens. A total of 360 hens were randomly assigned to five groups (6 replicates/group, 12 hens/replicate) and fed basal diets supplemented with 0% (control), 0.1%, 0.2%, 0.4%, or 0.8% SiO₂ for 8 weeks. Laying performance, egg quality, serum immune indices, reproductive hormone levels, antioxidant status, and serum trace element concentrations were determined. The results showed that dietary SiO₂ supplementation significantly affected egg production rate (p < 0.05), with the 0.2% group achieving the highest rate compared to the control. For egg quality, yolk weight and yolk thickness were significantly reduced only in the 0.8% group (p < 0.05), while other parameters were unaffected (p > 0.05). Dietary supplementation with 0.2%, 0.4%, and 0.8% silica significantly increased serum levels of IL-2 and IL-4 (p < 0.05), whereas the 0.8% supplementation decreased IL-1 levels (p < 0.05). Compared with the control group, serum IgA and IgG levels were elevated in the 0.2%, 0.4%, 0.8% silica-supplemented groups (p < 0.05), and serum IgM levels were higher in the 0.4% and 0.8% groups (p < 0.05). Regarding reproductive hormones, dietary SiO₂ significantly increased serum concentrations of β-endorphin, estradiol, growth hormone, luteinizing hormone, and progesterone (p < 0.05), with follicle-stimulating hormone elevated in the 0.4% and 0.8% groups (p < 0.05). Dietary silica supplementation did not affect serum activities of SOD, GSH-Px, CAT, or T-AOC. Serum POD activity decreased gradually and was significantly lower in the 0.2%, 0.4%, and 0.8% groups than in the control group (p < 0.05). Furthermore, SiO₂ supplementation significantly altered serum Cu and Zn levels (p < 0.05), with the 0.8% group having the highest Ca concentration and the 0.1–0.8% groups showing increased Zn levels compared to the control; no effects on Fe and Mn were observed (p > 0.05). In conclusion, dietary supplementation with 0.2–0.4% SiO₂ effectively improves egg production rate, along with enhancing immune function, modulating reproductive hormone secretion, and regulating serum Cu/Zn homeostasis in late-phase laying hens. Full article

Background: An early menopause (by definition, menopause that occurs at a woman’s age 40 through 45) is often associated with certain changes in the body that can result in risks for health-related conditions, an extended period later. Thus, scientists have begun examining how vitamin D has been suggested to be associated with endocrine function regulating both hormones and reproductive function during this time. However, it is not yet clear as to whether or not vitamin D provides any benefit to women who have experienced an early menopause. Material and Methods: The data was collected from 272 women in this retrospective, observational study at The County Hospital, Department of Obstetrics and Gynecology, Arad. The method of grouping the sample included two stratifications into early and physiological menopause categories based on amenorrhoea for a minimum of 12 consecutive months. 25-hydroxyvitamin D (25(OH)D) levels were classified into three categories: deficiency (<20 ng/mL), insufficiency (21–29 ng/mL), or adequacy (≥30 ng/mL). Estradiol, progesterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) hormone parameters were measured using standard immunoassays. The analysis employed correlation and regression to evaluate potential relationships between 25(OH)D levels and hormone parameters. Results: A significant proportion of the study group had a vitamin D deficiency. This was supported by the fact that only 24.27% of women were identified as having adequate levels of vitamin D, while the rest (62.03%) did not. Women in the early menopause group had a statistically significant negative relationship between estradiol and FSH (i.e., r = −0.29, p = 0.0016), as well as between progesterone and LH (i.e., r = −0.207, p = 0.026). There was not a statistically significant relationship between total sample vitamin D and estradiol (i.e., r = −0.038, p = 0.686) nor between vitamin D and progesterone (i.e., r = 0.031, p = 0.744). Women with vitamin D blood levels of 30 ng/mL or more showed a strong negative relationship between vitamin D and estradiol (r = −0.780; p = 0.0016) and a moderate positive relationship with progesterone (r = 0.534; p = 0.0104). However, these relationships were inconsistent in other groups. All group comparative analyses showed that women in the early menopause group had much lower estradiol levels than those in the physiological menopause group, regardless of whether they were classified based on their vitamin D levels (p < 0.0001). Conclusions: Women experiencing early or physiological menopause are at risk of having low vitamin D levels. However, our study results do not show a consistent relationship between serum 25(OH)D concentrations and serum estradiol or progesterone concentrations among the study population, suggesting that vitamin D is not a major factor influencing hormonal changes during menopause. These findings were inconsistent across analyses and should be interpreted cautiously. Overall, the results do not support a significant association between serum 25(OH)D concentrations and reproductive hormone levels in our study population. Full article

Tissue engineering using the self-assembly approach represents a promising technology. However, age-related reductions in extracellular matrix deposition by stromal cells limit the mechanical robustness of reconstructed tissues what can be critical for midurethral sling reconstruction. Indeed, stress urinary incontinence predominantly affects women over 50 years of age and is commonly treated by implantation of midurethral slings, whose synthetic versions have raised concerns regarding safety and long-term tolerance. In this study, we investigated whether biochemical modulation could enhance collagen deposition and mechanical properties of self-assembled dermal tissues reconstructed from female donors of different ages. Dermal fibroblasts were cultured in the presence of ascorbic acid, and the effects of hormonal supplementation, metabolic and hypoxia-related stimuli, and insulin signaling activation were evaluated using collagen quantification, histological analyses, and mechanical testing. Fibroblasts derived from younger donors deposited significantly more collagen than those from older female donors. Among all tested conditions, insulin like growth factor 1 (IGF 1) markedly increased collagen deposition in a dose-dependent manner, including in fibroblasts from women over 50 years of age, whereas β-estradiol and progesterone had no significant effect on collagen content. Although β-estradiol slightly increased tissue thickness, only IGF-1 supplementation resulted in substantial improvements in perforation strength, stiffness, displacement at break, and toughness. These results demonstrate that IGF-1 is a potent enhancer of extracellular matrix production and mechanical performance in dermal tissues reconstructed by the self-assembly approach, and represents a promising strategy to improve the development of biological midurethral slings. Full article

Objectives: Oocyte pick-up (OPU) is commonly performed under propofol-based sedation during in vitro fertilization (IVF). However, considerable interindividual variability in propofol requirement has been observed. Controlled ovarian hyperstimulation results in supraphysiological levels of ovarian steroid hormones, which may influence anesthetic sensitivity. This study aimed to evaluate the relationship between preprocedural serum estradiol and progesterone levels and propofol requirement during OPU performed under bispectral index (BIS)-guided sedation. Methods: In this prospective observational study, 96 women undergoing OPU were included. Serum estradiol and progesterone levels measured on the day of the procedure were recorded. Sedation was performed using a standardized protocol with midazolam, fentanyl, and propofol titrated to maintain BIS values between 40 and 60. Propofol consumption was normalized to body weight (mg/kg) and procedure duration (μg/kg/min). Correlation analyses and multivariable linear regression models were used to evaluate associations. Results: Mean propofol consumption was 157.3 ± 53.1 mg (2.41 ± 0.83 mg/kg), corresponding to an infusion rate of 125.7 ± 69.6 μg/kg/min. In multivariable analysis, estradiol levels were independently associated with propofol requirement (β = 0.238, p = 0.014), whereas progesterone levels were not significantly associated with anesthetic dosing after adjustment. BMI (β = −0.305, p = 0.002) and procedure duration (β = 0.224, p = 0.021) were also identified as independent predictors. Conclusions: Estradiol levels were associated with propofol requirement during OPU performed under BIS-guided sedation. However, given the observational design and the modest magnitude of the observed associations, these findings should be interpreted cautiously. BMI and procedure duration appeared to be more consistent predictors of propofol administration. Full article

The weaning-to-estrus interval (WEI) is an important indicator of sow reproductive performance, yet the mechanisms underlying post-weaning anestrus in Tibetan sows remain unclear. In this study, multiparous Tibetan sows were classified into an estrus group (FQ) and an anestrus group (WQ) based on estrus status after weaning. Serum reproductive hormones, hematological parameters, gut microbiota (16S rRNA sequencing), and fecal metabolites (untargeted metabolomics) were analyzed. Compared with the FQ group, the WQ group showed significantly lower estradiol (E₂) and higher progesterone (P) levels (p < 0.01), along with a decreased proportion of neutrophils and an increased proportion of lymphocytes (p < 0.05). No significant differences in alpha diversity were observed, whereas PLS-DA revealed differences in microbial community structures between groups. LEfSe analysis indicated that Methanobrevibacter and Acinetobacter were enriched in the FQ group, whereas Muribaculaceae and Prevotella were enriched in the WQ group. Differential metabolites were mainly involved in amino acid and lipid metabolism and enriched in pathways related to steroid hormone biosynthesis, oocyte maturation, and tryptophan metabolism. These findings suggest that post-weaning anestrus may be associated with endocrine imbalances, immune changes, and gut microbiota–metabolite interactions. They may provide a basis for future studies in Tibetan pig breeding and genetic improvement. Full article

Females with iron overload suffer from follicular dysplasia, and effective therapeutic strategies for preserving fertility remain lacking. As a natural aliphatic polyamine, spermidine exerts antioxidant activity and plays an anti-ferroptosis role in the pathogenesis of various diseases. However, the role and underlying mechanism of spermidine in iron overload-induced ovarian ferroptosis remain largely elusive. This study aimed to investigate the therapeutic potential of spermidine against iron overload-induced ferroptosis in ovarian granulosa cells and elucidate its molecular mechanism. As a result, iron overload models were established in female mice (in vivo, ferrous sulfate) and porcine ovarian granulosa cells (in vitro, ferric ammonium citrate), with spermidine administered at 3 mM (in vivo) or 150 μM (in vitro). Ferritin heavy chain (FHC) and solute carrier family 7 member 11 (SLC7A11) silencing were performed via siRNA transfection, and relevant controls were set. In vivo studies showed that spermidine elevated serum estradiol and progesterone levels, enhanced ovarian catalase (CAT) and superoxide dismutase (SOD) activities, improved granulosa cell mitochondrial morphology, and increased estrous cycle regularity from 35.6% (high-iron group) to 63.1%. In vitro, spermidine improved ferric ammonium citrate (FAC)-impaired cell viability; attenuated reactive oxygen species (ROS) accumulation; upregulated FHC, Nrf2/p-Nrf2/GPX4, SLC7A11 and anti-müllerian hormone (AMH) expression; and inhibited excessive autophagy (decreased LC3BII/I ratio). Mechanistically, spermidine activated AKT-mediated autophagy, modulated iron homeostasis and glutathione (GSH) synthesis via FHC, alleviated ferroptosis-related Nrf2/p-Nrf2/HO-1 pathway overactivation, reduced lipid peroxidation and DNA damage, and restored mitochondrial function. SLC7A11 silencing disrupted glutathione metabolism, induced mitochondrial ROS accumulation, and inhibited autophagy. Proteomic analysis identified microsomal glutathione S-transferase 3 (MGST3) as a potential key downstream target of spermidine in suppressing SLC7A11-mediated ferroptosis. This study reveals a novel therapeutic strategy wherein spermidine protects against ovarian ferroptosis and preserves ovarian function by regulating iron homeostasis through the FHC/SLC7A11 axis. Full article

This study demonstrated the effects of dietary supplementation with 1% raspberry (RO) or 1% strawberry (SO) seed oil from 5 to 12 weeks of age (n = 6/group) on folliculogenesis, hormonal parameters, the ovarian fatty acid profile, and the expression of related genes in juvenile rabbits. After slaughter, ovaries and blood were collected. Ovaries were used for histology, fatty acid profiling, and gene expression analysis, while plasma was used to measure progesterone (P4), testosterone (T), estradiol-17β (E2), follicle-stimulating hormone (FSH), and anti-Müllerian hormone (AMH) concentrations. Both RO and SO reduced the number of primary follicles (p = 0.04), whereas RO increased the number of antral follicles (p = 0.04) compared with the control. In both supplemented groups, FSH (p = 0.04 and p = 0.035) and AMH (p = 0.04) concentrations were higher. RO increased P4 and E2 (p = 0.03 and p = 0.013) concentrations, while SO only increased P4 (p = 0.02) levels. SO altered the ovarian fatty acid profile, increasing selected monounsaturated fatty acids and reducing polyunsaturated fatty acids, likely by increasing the expression of the converting enzyme, stearoyl-CoA desaturase 5 (p = 0.038). Overall, both oils influenced folliculogenesis through hormonal changes, and SO modified ovarian fatty acid composition, which may affect ovarian function in juvenile rabbits. Full article

The placenta produces a variety of steroid hormones through the catalytic activity of steroidogenic enzymes, including cytochrome P450 (CYP) hydroxylases and hydroxysteroid dehydrogenases (HSD). Large amounts of progesterone produced by the placenta are essential for the maintenance of pregnancy. Although androgens and estrogens are also elevated in maternal circulation during gestation, there are conflicting reports on whether de novo synthesis of these steroids occurs in the human placenta. To address this issue, we performed a comprehensive analysis of steroidogenic gene expression in early and term placenta. While none of the genes examined showed binary expression changes, 17β-HSDs, including HSD17B1 and AKR1C3, were markedly upregulated in the term placenta. CYP19A1 and HSD11B2 genes were also markedly upregulated. In contrast, CYP17A1, CYP21A2, CYP11B1, CYP11B2, and HSD17B3 were almost undetectable. Consistent with these findings, the plasma ratios of active to precursor sex steroids (estradiol/estrone and testosterone/androstenedione) were higher in pregnant than in non-pregnant women, although concentrations of all steroids increased. In contrast, plasma levels and profiles of 11-oxygenated androgens were unchanged. These results indicate that the human placenta does not significantly contribute to circulating levels of either classical or novel classes of androgens. Therefore, this study provides new insights into the tissue of origin and the physiological significance of sex steroids during gestation. Full article

Objective: To evaluate the association of salivary progesterone and estradiol levels and the progesterone-to-estradiol ratio (P4/E2 ratio) in early pregnancy with threatened miscarriage and pregnancy outcome. Methods: This single-center prospective cohort study was conducted at the Department of Obstetrics and Gynecology, Ankara Atatürk Sanatorium Training and Research Hospital, between 10 January 2025 and 10 January 2026. Primigravid women with a confirmed live intrauterine pregnancy were included. Saliva samples were collected at 6–7 and 8–9 weeks of gestation; in pregnancies remaining viable to 12 weeks, salivary estradiol was also measured at week 12. Progesterone and estradiol levels were measured by immunoassay, and the P4/E2 ratio was calculated. Participants were classified as healthy ongoing pregnancies to 12 weeks (n = 102), threatened miscarriage with viability preserved to 12 weeks after progesterone treatment (n = 63), and miscarriage (n = 29). Group comparisons were performed using the Kruskal–Wallis test, one-way ANOVA, Mann–Whitney U test, and paired-samples t-test, as appropriate. Results: At both 6–7 and 8–9 weeks, progesterone, estradiol, and the P4/E2 ratio differed significantly among groups. Values were highest in uncomplicated ongoing pregnancies, lowest in pregnancies ending in miscarriage, and generally intermediate in progesterone-treated threatened miscarriage with preserved viability. The progesterone-to-estradiol ratio increased significantly from 6–7 to 8–9 weeks in uncomplicated ongoing pregnancies (p = 0.005), whereas no significant longitudinal change was observed in the threatened miscarriage group. Among pregnancies viable at 12 weeks, estradiol levels at week 12 remained significantly lower in women with prior vaginal bleeding (p < 0.001). Conclusions: Salivary progesterone, estradiol, and the progesterone-to-estradiol ratio were significantly associated with early pregnancy outcome in this prospective cohort. These findings suggest that salivary hormonal assessment may provide a non-invasive adjunct for characterizing early hormonal patterns in threatened miscarriage; however, it should not be interpreted as a stand-alone prognostic tool without further validation in larger cohorts. Full article