Approximately 50% of human pregnancies humans fail, most before or during implantation. One factor contributing to pregnancy loss is abnormal glucose metabolism in the endometrium. Glucose contributes to preimplantation embryo development, uterine receptivity, and attachment of the embryo. Across multiple species, the epithelium stores glucose as the macromolecule glycogen at estrus. This reserve is mobilized during the preimplantation period. Glucose from circulation or glycogenolysis can be secreted into the uterine lumen for use by the embryo or metabolized via glycolysis, producing ATP for the cell. The resulting pyruvate could be converted to lactate, another important nutrient for the embryo. Fructose is an important nutrient for early embryos, and the epithelium and placenta can convert glucose to fructose via the polyol pathway. The epithelium also uses glucose to glycosylate proteins, which regulates embryo attachment. In some species, decidualization of the stroma is critical to successful implantation. Formation of the decidua requires increased glucose metabolism via the pentose phosphate pathway and glycolysis. After decidualization, the cells switch to aerobic glycolysis to produce ATP. Paradoxically, the decidua also stores large amounts of glucose as glycogen. Too little glucose or an inability to take up glucose impairs embryo development and decidualization. Conversely, too much glucose inhibits these same processes. This likely contributes to the reduced pregnancy rates associated with conditions like obesity and diabetes. Collectively, precise control of glucose metabolism is important for several endometrial processes required to establish a successful pregnancy. The factors regulating these metabolic processes remain poorly understood.
Embryo implantation is vital for successful conception but remains to be fully understood. Trophoblast invasion is key for implantation, with anchorage and depth of placentation determined by its extent. There is a dearth of synchronous information regarding in vitro fertilisation (IVF), implantation site and trophoblastic thickness (TT). Our aim was to determine whether pregnancy implantation site and TT, had an impact on outcomes of IVF pregnancies. This prospective observational study was undertaken at a tertiary referral UK fertility unit over 14-months, collecting data on implantation site and TT from three-dimensional (3D) images of the uterus following early pregnancy scan. Of the 300 women recruited, 277 (92%) had live births, 20 (7%) miscarried, 2 (0.7%) had stillbirths and one (0.3%) had a termination. Significantly more pregnancies that resulted in miscarriage 7/20 (35%) were located in the lower uterine cavity when compared to ongoing pregnancies 15/277 (5%) (p<0.01). TT was significantly higher in ongoing pregnancies when compared with those who miscarried (7.2mm vs 5.5mm; p<0.01). Implantation in the lower half of the uterine cavity and decreased TT are significantly associated with an increased rate of miscarriage. Identification of those at risk should prompt increased monitoring with the aim of supporting these pregnancies.
The refinement of embryo culture media is essential in improving embryo viability and in vitro production efficiency. Our previous work demonstrated that the nutrients (carbohydrates, amino acids, and vitamins) in traditional culture media far exceed the need for an embryo and producing developmentally competent embryos in a reduced nutrient environment is feasible. Here, we aim to evaluate the impact of exogenous lipid and L-carnitine supplementation on bovine blastocyst development and refine our RN condition further. Zygotes were cultured in the control medium (100% nutrients) and reduced nutrient media containing 6.25% of the standard nutrient concentrations supplemented with L-carnitine and lipid free or lipid rich BSA. Increased blastocyst development was observed in the reduced nutrient lipid rich medium compared to the other two groups. However, in both reduced nutrient conditions, blastocyst cell numbers were lower than those obtained in the control condition. We then examined the expression level of 18 transcripts correlated with lipid metabolism, glucose metabolism, redox balance, and embryo quality, along with mitochondrial DNA copy numbers, ATP productions, and lipid profile. The results indicated lipid metabolism, embryo quality, and redox enzyme related genes were upregulated while glucose related gene was downregulated in embryos derived from reduced nutrient lipid rich condition Finally, we identified that the lipid rich BSA has enriched linoleic, stearic, oleic, palmitic, and alpha-linoleic fatty acids, a lipid profile that may contribute to the increased lipid metabolism and improved blastocyst development of the bovine embryos under the reduced nutrient condition.
Sex steroids are converted to bioactive metabolites and vice versa by endometrial steroid-metabolising enzymes. Studies indicate that alterations in this metabolism might affect endometrial receptivity. This pilot study determined whether the endometrial formation and inactivation of 17B-estradiol differed between the supposedly embryo-receptive endometrium and non-receptive endometrium of women undergoing IVF/ICSI. Endometrial biopsies were obtained from IVF/ICSI patients 5-8 days after ovulation in a natural cycle, prior to their second IVF/ICSI cycle with fresh embryo transfer (ET). Endometrial biopsies from patients who achieved clinical pregnancy after fresh ET (n=15) were compared with endometrial biopsies from patients that did not conceive after fresh ET (n=15). Formation of 17B-estradiol (oxidative 17B hydroxysteroid dehydrogenases [HSDs]), estrone (reductive HSD17Bs) and inhibition of HSD17B1 activity was determined by high-performance liquid chromatography (HPLC). The endometrial transcriptome was profiled using RNA-sequencing followed by principal component analysis and differentially expressed gene (DEG) analysis. The False Discovery Rate-adjusted p<0.05 and log FoldChange>0.5 were selected as screening threshold. Formation and inactivation of 17B-estradiol resulted similar between groups. Inhibition of HSD17B1 activity was significantly higher in the non-pregnant group when only primary infertile women (n=12) were considered (27.1%,n=5 versus 16.2%,n=7,p=0.04). Gene-expression analysis confirmed the presence of HSD17B1 (encoding HSD17B1), HSD17B2 (encoding HSD17B2) and 33 of 46 analysed steroid metabolizing enzymes in the endometrium. In the primary infertile subgroup (n=10) 12 DEGs were found including LINC02349 which has been linked to implantation. However, the exact relationship between steroid metabolizing enzyme activity, expression and implantation outcome requires further investigation in larger, well-defined patient groups.
The field of fertility preservation (FP) for oncology patients has evolved significantly in recent years, offering new possibilities for individuals with life-threatening illnesses. We commend Jones et al. for their comprehensive ethical review of offering FP to patients with poor prognoses, acknowledging the potential benefits that it may bring. ‘Poor prognosis’ in this context implies a high likelihood of death due to cancer progression. We highlight the importance of considering posthumous reproduction, involving the use of cryopreserved gametes or embryos to conceive a child after one or both partners have passed away, a topic briefly mentioned by Jones et al. Posthumous reproduction raises complex ethical, logistical, and legal questions. Distinctions between cryopreserved sperm and oocytes are discussed, with each scenario presenting unique challenges. The article also examines the complexities faced by same-sex couples in posthumous reproduction, addressing issues related to donor selection, legal parentage, and rights. Legal and regulatory aspects play a crucial role, including obtaining clear and legally valid consent, defining parental rights, navigating surrogacy laws, and addressing inheritance and estate planning. Ethical dilemmas require healthcare professionals to ensure informed decision-making, consider psychological impacts, and offer information on alternative family-building options.
Cancer treatments can have a negative impact on a person’s ability to have children, and some cancer survivors may end up being unable to conceive. Fortunately, there are currently available technologies that can help preserve fertility for these patients. These options include freezing eggs or sperm before starting cancer treatment. For patients who have been diagnosed with cancer and have a poor prognosis, meaning they are not likely to survive their illness, it is crucial to think about what happens to their frozen eggs and sperm in case of their death. This process of conceiving a child after someone's passing is known as ‘posthumous reproduction’. In our article, we explore the ethical, legal, and logistical challenges that the surviving partners of patients who may not live long enough to have a child with their frozen eggs or sperm might face. We pay particular attention to same-sex couples because their surviving partners often encounter more obstacles. In some countries, posthumous reproduction in these circumstances is even prohibited by law. There is a significant variation in the regulations related to posthumous reproduction, both between different countries and within individual countries. These differences need to be carefully considered when healthcare professionals counsel patients and their family members.
Jason AbbottSchool of Clinical Medicine, Medicine and Health, Division of Obstetrics and Gynaecology, UNSW, Sydney, NSW, Australia Gynaecological Research and Clinical Research (GRACE) Unit, Royal Hospital for Women, UNSW, Sydney NSW Australia
Cecilia NgSchool of Clinical Medicine, Medicine and Health, Division of Obstetrics and Gynaecology, UNSW, Sydney, NSW, Australia Gynaecological Research and Clinical Research (GRACE) Unit, Royal Hospital for Women, UNSW, Sydney NSW Australia The George Institute for Global Health, UNSW, Sydney, Australia
Mike ArmourNICM Health Research Institute, Western Sydney University, Sydney, Australia Translational Health Research Institute, Western Sydney University, Sydney, NSW, Australia Medical Research Institute of New Zealand (MRINZ), Wellington, New Zealand
Previous quantitative research has shown that cannabis use, mostly illicit, is used for symptom management amongst those with endometriosis living in Australia or New Zealand, but the drivers and barriers for use of legal, medicinal cannabis in this population are currently unclear. This study sought to investigate, via online focus groups, the perceptions, barriers, drivers, and experiences associated with cannabis use, whether legal or illicit, amongst 37 Australians and New Zealanders, aged 18–55, with a medical diagnosis of endometriosis. Previous cannabis usage was not required to participate. Discussion topics included strategies employed to manage symptoms, exploration of current medications, previous use of cannabis for pain management, and interest in using medicinal cannabis as a management strategy. Participants with moderate-to-severe symptoms of medically diagnosed endometriosis reported inadequacies with their current medical and self-management strategies and were inclined to try medicinal cannabis, both as part of their medical management and as part of a clinical trial. Barriers to medicinal cannabis adoption identified in this cohort included high costs of legal cannabis products, lack of clarity and fairness in current roadside drug testing laws and workplace drug testing policies, concern over the impact of stigma affecting familial, social and workplace life domains, and subsequent judgement and the lack of education/engagement from their medical providers regarding cannabis use. Given the interest in medicinal cannabis and the reported lack of effective symptom management, clinical trials are urgently required to determine the potential role that medicinal cannabis may play in reducing the symptoms of endometriosis.
Previous research has demonstrated that cannabis, either medically or illicitly obtained, is being used to manage the pain and associated symptoms of endometriosis in people across Australia and New Zealand. However, there are no clinical trials yet to determine how safe and effective medicinal cannabis might be for endometriosis symptoms. Before we design our clinical trial we wanted to get input from people in the community who have endometriosis to understand what kind of barriers there might be to both being in a clinical trial and using medicinal cannabis for their symptoms. Overall, the vast majority of participants were open to trying medicinal cannabis as a management option, driven mainly by inadequacies in their current medical and self-management strategies. Several barriers to adoption were identified, including the high costs of legal cannabis products, current drug driving laws or workplace drug testing policies, and the negative stigma around cannabis usage.
Surawich JeensukDepartment of Animal Sciences, University of Florida, Gainesville, Florida, USA Department of Livestock Development, Bureau of Biotechnology in Livestock Production, Pathum Thani, Thailand
The WNT inhibitory protein DKK1 has been shown to regulate the development of the preimplantation embryo to the blastocyst stage. In cattle, DKK1 increases the number of trophectoderm cells that are the precursor of the placenta. DKK1 can affect cells by blocking WNT signaling through its receptors KREMEN1 and KREMEN2. Here it was shown that the mRNA for KREMEN1 and KREMEN2 decline as the embryo advances in development. Nonetheless, immunoreactive KREMEN1 was identified in blastocysts using western blotting. DKK1 also decreased the amount of immunoreactive β-catenin in blastocysts, as would be expected if DKK1 was signaling through a KREMEN-mediated pathway. Thus, it is likely that KREMEN1 functions as a receptor for DKK1 in the preimplantation bovine embryo.
DKK1 is a molecule produced by the lining of the womb (uterus) that regulates the development of the early embryo. Here it was shown that a substance that responds to DKK1 called KREMEN1 is found in the embryos of cattle. In other cells, joining of DKK1 to KREMEN1 results in reduction in amounts of a protein called β-catenin. For the present study, it was shown that DKK1 treatment also reduced β-catenin in the cattle, which suggests that DKK1 can regulate the cattle embryo by attaching to KREMEN1.
Bisphenol A (BPA) is an endocrine-disrupting compound, used as the key monomer of polycarbonate plastics and epoxy resins. BPA has been detected in both humans and farm animals and has been correlated with decreased sperm counts and motility. BPS and BPF are structural analogs of BPA and are increasingly being used in manufacturing as BPA substitutes. In this study, we aim to assess the direct outcomes of BPA, bisphenol S (BPS), and bisphenol F (BPF) exposure on bovine sperm parameters in vitro to elucidate how they affect sperm quality and fertilization potential, and to assess whether BPS and/or BPF are less harmful than BPA. Sperm from three or more bulls was obtained from either fresh samples or cryopreserved straws and exposed to 0.05 mg/mL of BPA, BPS, and BPF in vitro. After 4 h incubation, motility, capacitation, apoptosis/necrosis, and mitochondrial membrane potential levels were measured by computer-assisted sperm analysis or computational flow cytometry. Results showed that BPA exposure significantly reduced both fresh and cryopreserved sperm motility, capacitation, viability and mitochondrial membrane potential levels. Furthermore, BPF significantly decreased motility, capacitation and mitochondrial membrane potential in cryopreserved sperm only. BPS did not have any significant effects on any of the parameters measured. Our results suggest that BPA is the most harmful to sperm, while BPF is toxic under certain conditions, and BPS seems to be the least detrimental. Overall, this study provides an understanding of how the ubiquitous environmental chemicals, bisphenols, may impact male fertility even after ejaculation.
Bisphenol A (BPA) is a widespread man-made compound found in plastic products and the environment, and has been detected in human and animal biological fluids. BPA has been previously investigated for its negative effects on health, including its detrimental impacts on reproductive cells. Concerns over the use of BPA has led to its ban in some countries and has introduced the use of ‘BPA-free’ products, which typically contain substitutes such as bisphenols S and F (BPS and BPF). This current study investigates the effects of bull sperm exposure to BPA, BPS, and BPF to evaluate their impacts on sperm quality. After exposure, both BPA and BPF lowered sperm mobility, organelle function (by reducing mitochondrial activity), and overall survival; while BPS had no effects. Overall, this study shows that BPA and its common replacement, BPF, can both act on sperm directly, reducing their overall quality and function.
In the context of a cancer diagnosis, fertility preservation interventions are used to mitigate the potential impact of gonadotoxic cancer treatment upon fertility. They provide patients with cancer the option to freeze their reproductive material to have their own biological child following treatment. The evidence suggests some clinicians are less likely to have fertility preservation discussions with patients who have an aggressive or metastatic cancer which has a poor prognosis. Although this is contrary to current policy recommendations, there is a lack of guidance relating to offering fertility preservation in the context of a poor prognosis to support clinicians. Controversy surrounds posthumous reproduction, and whether the wishes of the cancer patient, when living and deceased should take precedence over others’ well-being. We consider the question of whether cancer patients with a poor prognosis should be offered fertility preservation from an ethics perspective. We structure the paper around key arguments to which multiple ethical principles might pertain, first establishing a central argument in favour of offering fertility preservation based on respect for autonomy, before exploring counterarguments. We conclude by proposing that a defeasible assumption should be adopted in favour of offering fertility preservation to all cancer patients who might benefit from it. It is important to recognise that patients could benefit from fertility preservation in many ways, and these are not limited to having a parenting experience. The burden of proof rests on the clinician in collaboration with their multidisciplinary team, to show that there are good grounds for withholding the offer.
When a person is diagnosed with cancer, they may wish to consider undergoing fertility preservation procedures. These procedures give patients a chance to have their own biological child after completing cancer treatment. However, research suggests that cancer patients who have a poor prognosis are less likely to be offered fertility preservation treatment. In this paper, we consider the ethical implications of offering (or not) fertility preservation to this patient group, including using their sperm or eggs to reproduce after their death. We conclude that fertility preservation treatments should be offered to all cancer patients who might benefit from it, and we outline the many ways that benefit from this treatment can be gained. The decision to withhold the offer of fertility preservation treatment should be made between the patient’s clinician and their wider care team. They must be able to provide good reasons to explain why it was withheld.
Many parts of the animal and human body host groups of bacteria, viruses, and fungi that together are known as the microbiome. Microbiomes do not cause disease but are important for the healthy working of many systems in the body, including for reproduction and fertility. While the microbiome that lives in a reproductive tract play the most direct role, microbiomes from other areas of the body may also affect reproductive health. However, not much is known about how these groups of microorganisms regulate fertility as well as the health of parents and offspring and help animals to cope with environmental changes. Furthermore, compared to the large amount of research in laboratory species and humans, there is less information about domestic or wild animal species. This special series of Reproduction and Fertility on microbiomes is aimed at filling this gap with articles from experts highlighting important evidence in reproductive microbiomes, current research gaps, and new directions.