Reproduction & Fertility最新文献

Recently, fertility services have started resuming since COVID-19 was declared a pandemic, but there remains significant uncertainty in the way this care will be delivered in the United Kingdom. The objective of our study was to explore the impact of COVID-19 on individuals using fertility services in the United Kingdom. The study was conducted in two phases between May 2020 and July 2020: an online questionnaire involving 1212 participants and subsequent individual semi-structured telephone interviews with 15 participants. Through thematic analysis, we learned from the questionnaire findings that 74% of individuals identified as White British, 21% as Black and Minority Ethnic (BAME) and 2.6% as male. Ninety-six per cent of individuals from the questionnaire explained that COVID-19 had a 'negative impact' on their fertility treatment, namely 'delay in care'. Eighty-two per cent of participants discussed concerns about the 'uncertainty' they felt about fertility services; these included the 'unknown impact of COVID-19 on pregnancy outcomes', the 'unknown impact on general gynaecology services' and the 'unknown impact of COVID-19 on fertility success'. Through semi-structured telephone interviews with 15 participants, we learned about the 'cultural pressures' individuals from BAME backgrounds faced in relation to care. Participants were mindful about the 'pressures on the service' when reopening, and therefore 'advancing maternal age', 'socio-economic background' and 'previous unsuccessful fertility treatment' were the main factors individuals considered important when 'prioritising' fertility care. Our findings can be used by fertility service providers to appreciate the patient perspective when considering the reopening of fertility services nationally and internationally.

Lay summary: The impact of COVID-19 on patients seeking or undergoing fertility treatment is not entirely known. Many patients have had their treatment postponed during the pandemic. As fertility services begin to recommence, it is important to understand how the pandemic has affected this group of patients. In addition, it is vital to appreciate and understand the patient's voice in order to ensure services take into account the patients' concerns as they begin to offer certain fertility treatments. Our study was conducted in two phases and involved an online questionnaire and individual interviews with people. We found that people were worried about services restarting and how care would be prioritised. People also discussed some of the perceived barriers to seeking fertility healthcare. Our findings highlight the importance of understanding the patient's voice when recommencing fertility services.

Using an in vivo assay, we selected 11 genes that were highly upregulated during the induction of ovulation in zebrafish using microarray analysis and RNA sequencing. The starmaker gene (stm) was one of these genes. Although stm has been previously reported to be involved in otolith formation during the early development of zebrafish, we detected its expression in eggs and showed that stm was related to fertilization by establishing an stm gene knockout strain using the CRISPR/Cas9 system. Further phenotypic analysis of stm knockout fish was conducted in this study. With a higher nonfertilization rate, the stm mutant strain showed an extremely low survival rate. Otoliths of stm homozygous mutant zebrafish showed abnormal morphology in embryos and adult fish. However, fish did not show any abnormalities in swimming behaviour in either embryos or adults. Stm proteins were detected on the chorion of ovulated eggs before spawning. Fibre-supported knob-like structures on the fertilization envelope (FE) also showed abnormal structures in stm mutants. The Stm protein is necessary for otolith formation, and a lack of Stm causes abnormal otolith formation. The partial defect of otolith formation does not cause defects in swimming behaviour. The Stm protein is expressed in the chorion and is responsible for the formation of fibre-supported knob-like structures on the FE. It was suggested that a lack of Stm caused a lower fertilization rate due to inadequate formation of the FE.

Lay summary: In zebrafish, the protein Starmaker (Stm) was identified as having a role in ovulation. Stm is also known to be required for the formation of ear stones (otoliths) which are needed to keep the body in balance. Zebrafish lacking Stm were produced by genome editing. As expected, Stm-deficient fish formed abnormal otoliths. To investigate the role of Stm in ovulation, fertilization and early development, we tried mating of Stm mutants and observed their juveniles. Although no problem found in ovulation, we found low fertilization rate and abnormal structure of knob-like structure (small pit) on the egg membrane. Survival rate of embryos with abnormal egg membrane was extremely low. It was demonstrated that Stm protein is necessary to form the functional egg membrane to protect embryos from the outside environment.

Today periodontal health is considered as an integral part of systemic health itself and no longer as a single factor. The literature recognizes that the presence of periodontal disease can represent a risk factor for numerous systemic conditions such as heart disease and diabetes. In recent years, we have witnessed a progressive interest regarding the influence exerted by this condition on reproduction, as well as the possible repercussions on conception possibilities. Upon analyzing a limited number of studies available for the correlation between periodontal disease and female infertility, it could be inferred that this condition can be equated to the presence of a real outbreak of infection and therefore exert its influence, not only through bacterial translocation in the bloodstream, causing the systemic dissemination of pathogens, but also through the production of cytokines and immunoglobulins by inflammatory mediators. This situation limits bacterial growth, but it could cause damage to the fetus, to the reproductive system, and could hinder conception attempts. Although further research is needed to better clarify the mechanism underlying the possible correlation between periodontal disease and female infertility, the present article aims to review all the available literature on this topic.

Lay summary: In recent years, interest regarding the influence of gum disease on conception has increased. Since serious gum disease (periodontitis) can be compared to an outbreak of infection, studies suggest that the bacteria that mediate inflammation do not remain confined only to the gum tissue, but can enter the bloodstream and spread, thus spreading the infection and having a whole-body effect. This situation could cause damage to the developing baby, to the reproductive system and could hinder conception attempts. Constant maintenance of oral health is definitely necessary. It is important for the professionals involved (gynecologists, obstetricians, dentists, etc.) to communicate and collaborate on these issues. Dentists could advise on the correct hygienic maintenance not only to pregnant women, but also to those who are planning a pregnancy in order to avoid the occurrence of unfavorable conditions.

Purpose: Following reports of an increase in implantation and pregnancy continuation rates by a higher percentage of Lactobacillus in the intrauterine microbiota, it has received attention in infertility treatment. This study aimed to examine Japanese women for intrauterine microbiota.

Methods: The clinical background factors in women that influence the abundance of Lactobacillus in the bacterial microbiota were examined. We included 147 patients (31 and 116 in the follicular and luteal phase, respectively), from June 2018 to June 2020, who underwent their first intrauterine microbiota test and had not used antibiotics for at least 4 weeks before the test. In the luteal phase, we compared the background factors of women in cases with 90% or more and less than 90% of Lactobacillus. Differences in the intrauterine microbiota were examined during the follicular and luteal phases.

Results: The proportion of Lactobacillus tended to be low among women aged 36 years and older with a history of childbirth (P = 0.0631). Some bacteria were only detected during the follicular and luteal phases, and the bacterial microbiota may change during the menstrual cycle.

Conclusion: Bacterial microbiota in the uterus may differ between the follicular and luteal phases. Furthermore, it was shown that the rate of Lactobacillus may be lower in women (older than 36 years) who had given birth, indicating that intrauterine microbiological testing may be considered for these women in clinical practice.

Lay summary: Good implantation and pregnancy continuation rates have been reported when the proportion of the bacteria Lactobacillus is high in the uterus (intrauterine) bacterial population (microbiota). In this study, we assessed whether the clinical background of Japanese women (age, history of pregnancy and childbirth, and presence of gynecological or hormonal disorders) affect the proportion of intrauterine microbiota. Intrauterine samples were collected and sequenced to evaluate the intrauterine microbiota and the composition ratio of each bacterium. Comparing the percentage of Lactobacillus in the latter phase of the menstrual cycle with the clinical background, it was found that the percentage tended to be lower in women with a history of childbirth. We compared the intrauterine microbiota between the first phase and latter phase of the menstrual cycle and revealed that it may differ between the two phases. Advances in the development of criteria for assessing intrauterine microbiota are expected.

The role that lifestyle factors play in fertility issues has generated some amount of interest and questions among stakeholders. This review aims to highlight the impact of lifestyle behaviors on the fertility potential of an individual and what can be done to prevent or improve reproductive outcomes. Relevant published articles on the effect of lifestyle behaviors were obtained from Medline, Pubmed and Google scholar search engines for the study. The review of the literature indicates a negative impact of modifiable lifestyle factors such as fat-rich diets, delayed childbearing/age of starting family, smoking, alcohol misuse, sexual behavior, anxiety/depression and perception/beliefs were associated with fertility. The ensuing stress precipitates social behaviors such as excessive alcohol and caffeine consumption, tobacco smoking, misuse of recreational drugs/medications, which increases the risk of sexually transmitted diseases and infection leading to infertility. Practical recommendations to modify lifestyle behaviors and the impact of misconception of Assisted Reproductive Technology in the treatment of infertility are discussed. The need to make appropriate behavioral changes to stem the tide of infertility in Nigeria is imperative. More reproductive health education is needed to create the necessary awareness of the etiologies of infertility and the importance of in vitro fertilization treatment as a means of conceiving 'natural' babies is suggested.

Lay summary: Scientific evidence has suggested that modifiable lifestyle factors (consumption fat-rich diets, delayed childbearing/age of starting family, smoking, alcohol misuse, sexual behavior, anxiety/depression and perception/beliefs) play important roles in the general health and wellbeing of individuals including fertility. Evidence exists of an association between lifestyle behaviors and infertility in both men and women. Understanding the various processes through which modifiable lifestyle behaviors impair fertility will help to assist in the management of affected individuals. We conducted a comprehensive review of published studies to assess how lifestyle factors inhibit fertility and practical ways to ameliorate them. This review also deals with the misconception of Assisted Reproductive Technology in the treatment of infertility. The need to make appropriate behavioral changes to stem the tide of infertility in Nigeria is imperative. More reproductive health education is needed to create the necessary awareness of the causes of infertility and the importance of in vitro fertilization in the treatment of infertility.

Altered gut microbiota (dysbiosis), inflammation and weight gain are pivotal to the success of normal pregnancy. These are features of metabolic syndrome that ordinarily increase the risk of type 2 diabetes in non-pregnant individuals. Though gut microbiota influences host energy metabolism and homeostasis, the outcome (healthy or unhealthy) varies depending on pregnancy status. In a healthy pregnancy, the gut microbiota is altered to promote metabolic and immunological changes beneficial to the mother and foetus but could connote a disease state in non-pregnant individuals. During the later stages of gestation, metabolic syndrome-like features, that is, obesity-related gut dysbiotic microbiota, increased insulin resistance, and elevated pro-inflammatory cytokines, promote energy storage in adipose tissue for rapid foetal growth and development, and in preparation for energy-consuming processes such as parturition and lactation. The origin of this gestation-associated host-microbial interaction is still elusive. Therefore, this review critically examined the host-microbial interactions in the gastrointestinal tract of pregnant women at late gestation (third trimester) that shift host metabolism in favour of a diabetogenic or metabolic syndrome-like phenotype. Whether the diabetogenic effects of such interactions are indeed beneficial to both mother and foetus was also discussed with plausible mechanistic pathways and associations highlighted.

Lay summary: In non-pregnant women, increased blood glucose, fat accumulation, and prolonged immune response lead to obesity and diabetes. However, during the later stages of pregnancy, the changes in the body's metabolism described previously do not lead to disease, instead pregnancy facilitates the storage of sufficient energy in fat cells for rapid growth and development of the foetus. The excess energy stores also prepares the mother for labour and breastfeeding. This review examines the role of the normal bacteria in the digestive tract in this beneficial energy accumulation and transfer between the mother and foetus without leading to obesity, diabetes and hypertension in pregnancy.

The first attempts at generating functional human oocytes by using the transfer of patients' somatic cell nuclei, as DNA source, into donor enucleated oocytes date back to the early 2000s. After initial attempts, that gave rather encouraging results, the technique was abandoned because of adverse results with this technique in the mouse model. Priority was then given to the use of induced pluripotent stem (iPS) cells, based on excellent results in the mouse, where mature oocytes and live healthy offspring were achieved. However, these results could not be reproduced in humans, and oogenesis with human iPS cells did not continue beyond the stage of oogonium. These data suggest that the use of enucleated donor oocytes will be necessary to achieve fertilizable human oocytes with somatic cell-derived DNA. The main problem of all these techniques is that they have to meet with two, sometimes contradictory, requirements: the haploidization of somatic cell-derived DNA, on the one hand, and the remodeling/reprogramming of DNA of somatic cell origin, so as to be capable of supporting all stages of preimplantation and postimplantation development and to give rise to all cell types of the future organism. Further research is needed to determine the optimal strategy to cope with these two requirements.

Lay summary: The recourse to artificial oocytes, generated by using the patient's own DNA derived from cells of somatic origin, represents the ultimate opportunity for women who lack healthy oocytes of their own but yearn for genetically related offspring. Many different pathologies, such as ovarian cancer, premature ovarian failure, other ovarian diseases and natural, age-related ovarian decay can cause the absence of available oocytes. The demand for artificial oocytes is increasing continuously, mainly because of the tendency to postpone maternity to still more advanced ages, when the quantity and quality of oocytes is low. This minireview focuses on the generation of artificial oocytes using different strategies and scenarios, based on the accumulated experience in humans and experimental animals.

Isolation of ovarian follicles is a key step in culture systems for large mammalian species to promote the continued growth of follicles beyond the preantral stage in fertility preservation efforts. Still, mechanical isolation methods are user-skill dependent and time-consuming, whereas enzymatic strategies carry increased risk of damaging theca cell layers and the basement membranes. Here, we sought to determine an optimal method to rescue domestic cat (Felis catus) early antral and antral stage follicles from ovarian tissue and to evaluate the influence of isolation strategy on follicle development, survival, and gene expression during 14 days of in vitro culture in alginate hydrogel. Mechanical isolation was compared with 90 min digestion in 0.7 and 1.4 Wünsch units/mL Liberase blendzyme (0.7L and 1.4L, respectively). Mechanical isolation resulted in improved follicle growth and survival, and better antral cavity and theca cell maintenance in vitro, compared with 1.4L (P < 0.05) but displayed higher levels of apoptosis after incubation compared with enzymatically isolated follicles. However, differences in follicle growth and survival were not apparent until 7+ days in vitro. Expressions of CYP19A1, GDF9, LHR, or VEGFA were similar among isolation-strategies. Cultured follicles from all isolation methods displayed reduced STAR expression compared with freshly isolated follicles obtained mechanically or via 0.7L, suggesting that prolonged culture resulted in loss of theca cell presence and/or function. In sum, early antral and antral stage follicle development in vitro is significantly influenced by isolation strategy but not necessarily observable in the absence of extended culture. These results indicate that additional care must be taken in follicle isolation optimizations for genome rescue and fertility preservation efforts.

Recent studies in our laboratory have indicated that bovine embryos only use a small amount of the nutrients available to them in culture. Our objective was to evaluate the developmental and molecular response of bovine embryos when nutrient concentrations in the culture medium were significantly reduced. Following IVM and IVF, embryos were cultured in media containing 75, 50, and 25% (experiment 1) or 25, 12.5, and 6.25% (experiment 2) of the concentrations of nutrients (carbohydrates, amino acids, and vitamins) present in our control medium (100%). Blastocyst formation, hatching, and allocation of cells to the inner cell mass (ICM) and trophectoderm (TE) were evaluated on day 7. Although the number of TE cells was decreased (P < 0.05) when nutrient concentrations were ≤25% (73.8-124.1 cells), it was not until nutrient concentrations were reduced to 6.25% that blastocyst formation (18.3 ± 3.0%) and hatching (3.0 ± 1.3%) were inhibited (P < 0.05) compared to embryos cultured in the control medium (156.1 ± 14.1 cells, 40.0 ± 3.8%, 20.0 ± 3.1%, respectively). Inhibition of fatty acid oxidation (etomoxir) reduced (P < 0.05) blastocyst development, with more pronounced effects at lower nutrient concentrations (≤12.5%). Reducing nutrient concentrations was associated with increased activity of AMPK, decreased activity of mTOR, and altered abundance of transcripts for hexokinase 1 (HK1), carnitine palmitoyl transferase 2 (CPT2), lactate dehydrogenase A (LDHA), and pyruvate dehydrogenase kinase 1 (PDK1), consistent with an increase in glucose and fatty acid metabolism. Reduced nutrient conditions provide a unique perspective on embryo metabolism that may facilitate the optimization of culture media.

Lay summary: To support early embryo development in the first week after fertilisation, an appropriate mixture of nutrients (carbohydrates, amino acids, and vitamins) is needed in the culturing solution. However, refining these solutions to support optimal embryo health remains challenging. In this study, bovine (cow) embryos derived from abattoir material were used as a model for the development of other mammalian embryos, including humans. These embryos were cultured in the presence of 75, 50, 25, 12.5, or 6.25% of the nutrients present in control conditions (100%), which are similar to those reported for the fluids of the fallopian tubes and uterus. Embryo development was largely unaffected in the 75, 50, and 25% treatments, with some embryos developing in the presence of only 6.25% nutrients. Cow embryos are remarkably resilient to reduced concentrations of nutrients in their environment because they can utilize internal stores of fat as a source of energy.