Search Results (30)

Background and Objectives: Pregnancies resulting from assisted reproductive technology (ART) have been associated with placenta-related adverse outcomes. Uterine artery Doppler pulsatility index (UtA-PI) reflects placental function. This study aimed to examine whether second-trimester UtA-PI differs according to the conception method after adjusting for potential confounding factors. Materials and Methods: In this retrospective cohort study, we included data from February 2015 to August 2024, at the third Department of Obstetrics and Gynecology, School of Medicine, Faculty of Health Sciences, Aristotle University of Thessaloniki, Greece, on singleton pregnancies presenting for their routine antenatal care, including a second-trimester anomaly scan. Pregnancies conceived via ART, including those conceived via ovulation induction/intrauterine insemination (OI/IUI) or in vitro fertilization/intracytoplasmic sperm injection (IVF/ICSI), were compared to those conceived spontaneously. Multiple linear regression was employed to investigate the association between the mode of conception and log₁₀ UtA-PI values, adjusting for various confounders, including gestational age at the time of the scan, maternal weight, height, age, parity, mode of delivery, smoking status, pre-existing diabetes mellitus (type I or II), and pre-existing thyroid disease. Results: The study included 15,552 singleton pregnancies, of which 82 (0.5%) were conceived via OI/IUI and 690 (4.4%) were conceived via IVF/ICSI. The median UtA-PI values were 0.99 (IQR: 0.85–1.17) for spontaneous conception (SC), 1.00 (IQR: 0.86–1.16) for OI/IUI, and 0.90 (IQR: 0.76–1.12) for IVF/ICSI. The Kruskal–Wallis test indicated a statistically significant difference among these groups (p < 0.001). Pairwise comparisons using the Wilcoxon rank-sum test with Bonferroni correction revealed that UtA-PI values in IVF/ICSI pregnancies were significantly lower compared to both SC and OI/IUI pregnancies (p < 0.001 for both). No significant difference was observed between the SC and OI/IUI groups. In the multivariable linear regression model, IVF/ICSI conception was independently associated with lower log₁₀ UtA-PI values (estimate = −0.076, 95% CI: −0.096, −0.056) while no association was found for OI/IUI conception. Conclusions: Although ART has been associated with placental-related complications, mid-trimester UtA flow was found to be lower in IVF/ICSI pregnancies, suggesting better utero-placental flow in ART pregnancies and other possible mechanisms in the maternal–placental interplay for the development of pregnancy complications. Full article

Cannabis sativa L. is a dioecious species known to produce over 1600 chemical constituents, including more than 180 cannabinoids classified into 11 structural groups. These bioactive compounds are predominantly synthesised in the glandular trichomes of female inflorescences. However, sex determination in C. sativa is influenced by both genetic and environmental factors, often leading to the development of male flowers on female plants. This unintended fertilisation reduces cannabinoid yield and increases genetic heterogeneity and challenges in medical cannabis production. Haploid and doubled haploid (DH) technologies offer a promising solution by rapidly generating homozygous lines from gametophytic (e.g., unpollinated ovaries and ovules) or sporophytic tissues (e.g., anthers and microspores) via in vitro culture or chromosome reduction during hybridisation. In land plants, the life cycle alternates between a diploid sporophyte and a haploid gametophyte generation, both capable of mitotic division to form multicellular bodies. A single genome regulates this phase transition and encodes the molecular, genetic, and epigenetic mechanisms that precisely control the developmental processes unique to each generation. While the application of haploid technology in C. sativa remains limited, through recent progress in haploid induction (HI) and CRISPR-based genome editing, the direct modification of haploid gametes or embryos enables the creation of null homozygous lines following chromosome doubling, improving genetic uniformity. Understanding the molecular mechanisms of spontaneous chromosome doubling may further facilitate the development of elite cannabis genotypes. Ultimately, enhancing the efficiency of DH production and optimising genome editing approaches could significantly increase the speed of genetic improvement and cultivar development in Cannabis sativa. Full article

In many vertebrates, mature ovulated eggs are arrested at metaphase II prior to fertilization. The eggs exit meiotic arrest after fertilization-induced or parthenogenetic activation, followed by embryo development or egg degradation, respectively. Calcium-dependent activation of meiotically-arrested eggs has been thoroughly investigated in various species. In addition, several recent studies have detailed the excessive activation of ovulated frog eggs, so-called overactivation. This overview highlights the major events of overactivation observed in mature ovulated eggs of the African clawed frog Xenopus laevis with a focus on similarities and differences between spontaneous, oxidative stress-induced, and mechanical stress-induced overactivation. The dramatically different cell death scenarios that unfold in activated and overactivated eggs are also exposed in the article. Full article

The prevalence of infertility is increasing worldwide; poor nutrition, increased sedentary lifestyles, obesity, stress, endocrine-disrupting chemicals, and advanced age of childbearing may contribute to the disruption of ovulation and influence oocyte and sperm quality and overall reproductive health. Historically, infertility has been primarily attributed to female factors, neglecting the importance of male fertility; this has resulted in an incomplete understanding of reproductive health. Male factors account for 40–50% of infertility cases. In half of these cases, the proximal cause for male infertility is unknown. Sperm contributes half of the nuclear DNA to the embryo, and its quality is known to impact fertilisation rates, embryo quality, pregnancy rates, risk of spontaneous miscarriage, de novo autosomal-dominant conditions, psychiatric and neurodevelopment conditions, and childhood diseases. Recent studies have suggested that both the microenvironment of the testes and diet quality may play an important role in fertility; however, there is limited research on the combination of these factors. This review summarises current known causes of male infertility and then focuses on the potential roles for diet and the seminal microbiome. Future research in this area will inform dietary interventions and health advice for men with poor semen quality, potentially alleviating the need for costly and invasive assisted reproduction treatments and allowing men to take an active role in the fertility conversation which has historically focussed on women individually. Full article

Obesity reduces nitric oxide (NO) production due to endothelial nitric oxide synthase (eNOS) dysfunction, resulting in oxidative stress, mitochondrial dysfunction, and chronic inflammation. These factors have a negative impact on reproductive health, including oocyte quality, endometrial receptivity, and embryo implantation. When oxidative stress affects eNOS function, the nitrate–nitrite–nitric oxide (NO₃-NO₂-NO) pathway provides an alternate route for NO production. Bariatric surgery has been found to restore NO production, reduce oxidative stress, and improve fertility in morbidly obese women. This review investigates the molecular mechanisms by which bariatric surgery affects eNOS activity, the NO₃-NO₂-NO pathway, and oxidative stress reduction, with an emphasis on intracellular activities including mitochondrial biogenesis and NO production. A systematic review employing PRISMA criteria included articles published between 2000 and 2024 from PubMed, Scopus, and Embase that investigated NO₃-NO₂ pathways, oxidative stress markers, hormonal alterations, and reproductive outcomes in morbidly obese women following bariatric surgery. After evaluating 1542 studies, 11 were selected for the final analysis. Results showed a 45% increase in NO₃-NO₂ levels (p < 0.001), a 35% reduction in oxidative stress indicators (p < 0.01), a 60% increase in pregnancy rates, and a 50% increase in spontaneous ovulation rates following surgery. These benefits were connected to improved mitochondrial function and endometrial receptivity as a result of reduced oxidative stress and inflammation. The NO₃-NO₂-NO route is critical in compensating for lower NO generation under oxidative stress and hypoxia, and bariatric surgery significantly improves this pathway to optimize blood flow, mitochondrial function, and reproductive results. Full article

Myo-inositol (MYO) and D-chiro-inositol (DCI) are the two most significant isomeric forms of inositol, playing a critical role in intracellular signaling. MYO is the most abundant form of inositol in nature; DCI is produced from MYO through epimerization by an insulin-dependent enzyme. Recently, it has been demonstrated that inositol may influence oocyte maturation and improve intracellular Ca²⁺ oscillation in the oocytes, and it has been proposed as a potential intervention for restoring spontaneous ovulation. The MYO concentration in human follicular fluid is considered a bioindicator of oocyte quality. In the ovary, DCI modulates the activity of aromatase, thus regulating androgen synthesis. Under physiological conditions, the MYO/DCI ratio is maintained at 40:1 in plasma. In women with PCOS, the MYO/DCI ratio is lowered to 0:2:1, contributing to elevated androgen production. By regulating FSH signaling, MYO administration increases the number of high-quality embryos available for transfer in poor responder patients. Finally, by acting downstream to insulin signaling, inositol administration during pregnancy may represent a novel strategy for counteracting gestational diabetes. These findings show that diet supplementation with inositol may be a promising strategy to address female infertility and sustain a healthy pregnancy. Full article

Plant ploidy manipulation is often required for breeding purposes. However, there is no comprehensive review covering genome doubling in vegetable crops despite the abundance of data for a large number of vegetable species. Similar to other species, genome doubling is required in vegetable crops to obtain doubled haploids (DHs). It is also utilized for the production of polyploids to overcome interspecific hybrid sterility and improve agricultural traits. Spontaneous haploid genome duplication (SHGD) occurs in many Apiaceae, Brassicaceae, Cucurbitaceae, and Solanaceae crops, allowing for the laborious treatment with antimitotic agents to be bypassed. SHGD mechanisms are not fully understood, but existing data suggest that SHGD can occur via nuclear fusion, endoreduplication, or other mechanisms during microspore or ovule early embryogenic development. Other studies show that SHGD can occur at later developmental stages during extended plant growth in vitro or ex vitro, possibly due to the presence of phytohormones in the medium and/or diploid cell competitive advantage. For unresponsive accessions and species with rare SHGD, such as onion (Allium cepa L.) and beet cultivars (Beta vulgaris subsp. vulgaris L.), antimitotic agent treatment has to be applied. Antimitotic agent application efficiency depends on the treatment conditions, especially the agent concentration and exposure time. Also, plant developmental stage is critical for agent accessibility and plant survival. The existing methods can be used to further improve genome doubling methodology for major vegetable crops and other species. Full article

Hydrogen sulfide (H₂S), previously regarded as a toxic exhaust and atmospheric pollutant, has emerged as the third gaseous signaling molecule following nitric oxide (NO) and carbon monoxide (CO). Recent research has revealed significant biological effects of H₂S in a variety of systems, such as the nervous, cardiovascular, and digestive systems. Additionally, H₂S has been found to impact reproductive system function and may have therapeutic implications for reproductive disorders. This paper explores the relationship between H₂S and male reproductive disorders, specifically erectile dysfunction, prostate cancer, male infertility, and testicular damage. Additionally, it examines the impact of H₂S regulation on the pathophysiology of the female reproductive system, including improvements in preterm birth, endometriosis, pre-eclampsia, fetal growth restriction, unexplained recurrent spontaneous abortion, placental oxidative damage, embryo implantation, recovery of myometrium post-delivery, and ovulation. The study delves into the regulatory functions of H₂S within the reproductive systems of both genders, including its impact on the NO/cGMP pathway, the activation of K⁺ channels, and the relaxation mechanism of the spongy smooth muscle through the ROCK pathway, aiming to broaden the scope of potential therapeutic strategies for treating reproductive system disorders in clinical settings. Full article

Background: Combined oral contraceptives (COCs) work mostly by preventing the pre-ovulatory gonadotropin surge, but the action of COCs on spontaneous episodic and GnRH (gonadotropin-releasing hormone)-induced LH (luteinizing hormone) release has been poorly evaluated. Oral contraceptives are known to act on the spontaneous hypothalamic–pituitary functions reducing both GnRH and gonadotropin release and blocking ovulation. Aim: To evaluate spontaneous and GnRH-induced LH release during both phases of the menstrual cycle or under the use of the contraceptive pill. Methods: A group of 12 women, subdivided into two groups, volunteered for the study. Group A (n = 6, controls) received no treatments, while Group B (n = 6) received a 21 + 7 combination of ethinyl-estradiol (EE) 30 µg + drospirenone (DRSP) 3 mg. Both groups were evaluated twice: Group A during follicular and luteal phases, Group B during pill assumption and during the suspension interval, performing a pulsatility test, GnRH stimulation test, and hormonal parameters evaluation. Spontaneous and GnRH-induced secretory pulses were evaluated, as well as the instantaneous secretory rate (ISR). Results: COC treatment lowered LH and FSH (follicle stimulating hormone) levels significantly if compared to the follicular phase of spontaneous cycles. During the suspension interval, hormone levels rapidly rose and became comparable to those of the follicular phase of the control group. The LH pulse frequency under COC administration during the suspension interval was similar to that observed during the follicular phase (2.6 ± 0.3 pulses/180 min and 2.3 ± 0.2 pulses/180 min, respectively). The GnRH-induced LH peaks were greater in amplitude and duration than those observed after ISR computation in both groups. The GnRH-induced LH release during the luteal phase of the control subjects was higher than in the follicular phase (51.2 ± 12.3 mIU/mL and 14.9 ± 1.8 mIU/mL, respectively). Conversely, subjects under COC showed a GnRH-induced LH response similar during COC and during the suspension interval. Conclusions: Our data support that the EE + DRSP preparation acts on both spontaneous pulsatile release and GnRH-induced LH release during the withdrawal period of the treatment, and that after 5–7 days from the treatment suspension, steroidal secretion from the ovary is resumed, such as that of androgens. This suggests that in hyperandrogenic patients, a suspension interval as short as 4 days might be clinically better. Full article

Cystic ovarian disease (COD) in dairy cattle is characterized by preovulatory follicles that become cysts, fail to ovulate and persist in the ovary; consequently, interfering with normal ovarian cyclicity. The intraovarian key players that orchestrate the alterations occurring in the preovulatory follicle and that culminate with cyst formation and persistence, however, remain uncertain. Interestingly, the Hippo pathway effector yes-associated protein (YAP) has been described in humans and mice as a key player of anovulatory cystic disorders. To start elucidating if YAP deregulation in ovarian follicle cells can be also involved in the pathogenesis of COD, we have generated a series of novel results using spontaneously occurring cystic follicles in cattle. We found that mRNA and protein levels of YAP are significantly higher in granulosa (GCs) and theca cells (TCs) isolated from cystic follicles (follicular structures of at least 20 mm in diameter) in comparison to respective cell types isolated from non-cystic large follicles (≥12 mm). In addition, immunohistochemistry and Western blot analyses used to determine YAP phosphorylation pattern suggest that YAP transcriptional activity is augmented is cystic GCs. These results were confirmed by a significant increase in the mRNA levels encoding for the classic YAP-TEAD transcriptional target genes CTGF, BIRC5 and ANKRD1 in GCs from follicle cysts in comparison to non-cystic large follicles. Taken together, these results provide considerable insight of a completely novel signaling pathway that seems to play an important role in ovarian cystic disease pathogenesis in dairy cattle. Full article

There is evidence that replacing the gonadotropin-releasing hormone (GnRH) with porcine luteinizing hormone (pLH) to synchronize ovulation prior to artificial insemination (AI) increased pregnancy per AI in dairy cows without affecting blood progesterone (P₄) concentrations. Whether morphologic, steroidogenic, and transcriptomic differences exist among corpora lutea (CL) formed after ovulation induced by GnRH and pLH is unclear. Our main objective, therefore, was to compare CL characteristics between GnRH- and pLH-induced CL. In 24 non-lactating Holstein cows, ovulations were spontaneous (Spont-Ov) or induced with 100 µg GnRH, 25 mg pLH, or 1 mg estradiol benzoate (EB), with CL excised 12 d after ovulation. In pLH- versus GnRH-treated cows, the duration of elevated LH (above baseline) was prolonged (10 versus 6 h, respectively, p < 0.01), but CL dimensions, pixel intensity of CL images, proportions of steroidogenic and non-steroidogenic luteal cells, and mean plasma LH did not significantly differ. Post-ovulation mean plasma P₄ (ng/mL) did not differ among Spont-Ov (3.0) pLH (3.1) or GnRH (3.0) cows but were lower in EB cows (2.0). In vitro P₄ concentration was greater in luteal explants of pLH-treated cows than in all other groups (combined means, 16.0 vs. 12.3 µg/mL, p < 0.02). Relative abundance of mRNA for oxytocin receptor (OXTR) was 2-fold higher (p < 0.01) in CL of pLH vs. GnRH cows and highest in Spont-Ov CL. In summary, pLH-treated cows had a longer LH peak, and greatest luteal tissue concentrations and in vitro production of P₄. We inferred that increased P₄ concentrations at the ovarian–uterine level in pLH-treated cows could have promoted embryo development and increased pregnancy per AI. Full article

Background: Controversy exists in the literature regarding the possible association between infertility treatments in singleton pregnancies and long-term risk for childhood malignancy. Data regarding infertility treatments in twins and long-term childhood malignancies are scarce. Objective: We sought to investigate whether twins conceived following infertility treatments are at an increased risk for childhood malignancy. Study design: A population-based retrospective cohort study, comparing the risk for future childhood malignancy in twins conceived by infertility treatments (in vitro fertilization and ovulation induction) and those who were conceived spontaneously. Deliveries occurred between the years 1991 and 2021 in a tertiary medical center. A Kaplan–Meier survival curve was used to compare the cumulative incidence of childhood malignancies, and a Cox proportional hazards model was constructed to control for confounders. Results: During the study period, 11,986 twins met the inclusion criteria; 2910 (24.3%) were born following infertility treatments. No statistically significant differences were noted between the groups comparing the rate (per 1000) of childhood malignancies (2.0 in the infertility treatments group vs. 2.2 in the comparison group, OR 1.04, 95% CI 0.41–2.62; p = 0.93). Likewise, the cumulative incidence over time was comparable between the groups (log-rank test, p = 0.87). In a Cox regression model, controlling for maternal and gestational age, no significant differences in childhood malignancies were noted between the groups (adjusted HR = 0.82, 95% CI 0.49–1.39, p = 0.47). Conclusions: In our population, twins conceived following infertility treatments are not at an increased risk for childhood malignancies. Full article

Objective: The surgical management of polycystic ovary syndrome (PCOS) represents an unclear option compared to medical therapy, and it is necessary to deepen the role of minimally invasive surgery, represented by laparoscopic ovarian drilling (LOD) and transvaginal hydrolaparoscopy (THL), for the treatment of PCOS in infertile women resistant to drug therapy and to establish its success in terms of ovulation and pregnancy rates. Methods: A search was performed in the main electronic databases (MEDLINE, EMBASE, Web of Science, PubMed, and the Cochrane Library) from 1994 to October 2022 in order to evaluate the role of surgery in patients with PCOS resistant to pharmacological treatment. Only original scientific articles in English were included. Results: Seventeen studies were analyzed in this review. In all analyzed studies, more than 50% of the population underwent spontaneous ovulation after surgical treatment without great differences between the two surgical techniques (LOD and THL). More than 40% of patients delivered, with a higher rate after LOD, although eight ectopic pregnancies and sixty-three miscarriages were reported. A lower risk of adhesion formation after THL has been reported. No clear data regarding the effect of surgery on the regularization of the menstrual cycle has been described. A reduction in LH and AMH serum levels as well as the LH/FSH ratio compared to preoperative levels for both surgical techniques has been described. Conclusions: Despite the scarcity and heterogeneity of data, surgical therapy could be considered an effective and safe approach in the management of PCOS patients with resistance to pharmacological treatment who desire to become pregnant. Full article

Cows show spontaneous estrus over 8–20 h but become refractory to the bull about 10–12 h before ovulation. This indicates that ovulation occurs 10–12 h after the end of estrus behavior, yet spermatozoa from the bull ejaculate need to undergo maturation and capacitation for 6 to 8 h in the female reproductive tract before they are capable of fertilization. Traditionally, the onset of estrus has been considered the best timing for artificial insemination (AI) in cattle, that is, 6 to 24 h from the first signs of estrus. However, recent findings suggest this interval should be reduced to 16 to 6 h before ovulation, bringing it closer to the end of estrus. In this review, the end of estrus rather than its onset is proposed as the best guide for AI timing in dairy cattle, and physiological indicators of late estrus are discussed such as relaxation of the intravaginal part of the uterus, a lower cervical mucus viscosity and a softer pre-ovulatory follicular consistency as simple cues indicating a cow is ready for service. Full article

Fritillaria aurea, unlike other Fritillaria species, is a narrowly endemic species. It has a brown checkered speckled color on each tepal and also has regular yellow intense colors on the tepals. Its large bell-shaped appearance when the flower is open is one of its most striking ornamental features. However, F. aurea plant numbers are limited in their natural habitats, and their numbers are decreasing day by day; they are even confronted with the risk of extinction owing to the damage resulting from human activities. This detailed investigation of reproductive biology plays a vital role in determining the evolutionary success and survival of F. aurea, largely in determining the effectiveness of their reproductive performance. Our results indicate that the species exhibits a very low partial dichogamy and herkogamy structure, as well as self-incompatible pollination. The flowering period ranges from March to April. Average seed viability, average seed number, and seed germination were determined as 71%, 255, and 45%, respectively. The pollen viability, pollen grains, and stigma receptivity were found as 96%, 392.000, and 85%, respectively. The pollen/ovule ratio (P/O) and self-incompatibility index (SII) in the spontaneous cross-pollination were detected as 1537 and 0, respectively. Flowers of F. aurea were visited by several insect species, mostly honeybees (Apis mellifera); Bombus sp. and Vespa sp. also played a minor role in pollination. To sum up, these results not only lay a solid foundation for further reproductive biology investigations to more broadly reveal the mechanisms of F. aurea endangerment in the future but also provide a reliable theoretical basis for hybridization breeding of parents. Full article