Medicina Reproductiva y Embriología Clínica最新文献

Currently, many women see their reproductive potential reduced. On the one hand, socio-cultural changes have led to the postponement of motherhood with the consequent negative effects that advanced age has on the ovarian reserve. On the other hand, the increase in the incidence of cancer together with the numerous advances made in antineoplastic therapies have allowed many of the oncological patients to survive. As a result, many women show difficulties in carrying out their reproductive plans. In addition to this percentage of the female population, there are those who, for various reasons, experience early menopause. In this way, a new clinical focus is established whose common point lies in the presence of a diminished ovarian reserve which, therefore, does not respond adequately to hormonal stimulation. For this reason, and after demonstrating the existence of a residual ovarian reserve that can be recovered, new ovarian rejuvenation protocols are being developed that focus on the recovery of those sleeping follicles. Due to this alteration in ovarian function and the low follicular reserve of these patients, the application of current strategies for the preservation of fertility is not efficient. Therefore, in vitro follicular activation techniques and infusion of bone marrow-derived stem cells have been developed as new alternatives to improve follicular development in this type of patient.

The decision of a blastomere to become inner cell mass or trophectoderm relies on the integration of two types of information: position and polarity. Compaction and polarization play key roles in this first lineage decision, since they alter both the intra- and the intercellular organization of the embryo. In-depth studies of early embryogenesis using the mouse model have provided new insights into the molecular regulation of compaction, polarization and lineage specification. However, how these processes first emerge and influence subsequent molecular and cellular events remain open questions in the field. In this review, we summarize the chain of events that lead to the generation of the first two cell lineages, outlining how compaction and polarization can build cell identity. Such processes, despite running in parallel, are subjected to different regulatory pathways. Then, if under specific circumstances one of the regulatory pathways is affected, embryos may achieve compaction but may have severe problems to acquire full developmental potential.

Recommendations are made for the genetic screening of gamete donors. These recommendations are the result of the consensus reached by a work group consisting of representatives from the Spanish Fertility Society, the Spanish Association of Andrology, the Spanish Association of Medical Biopathology and Laboratory Medicine, the Association for the Study of Reproductive Biology and the Spanish Association of Human Genetics and were subsequently reviewed and approved by the executive boards of each of these associations. This document describes 2 types of genetic screening: a basic mandatory screening of all donors and an extended genetic screening for donor-recipient genetic matching. The importance of pre- and post-screening genetic counselling, the management of the occurrence of adverse reactions of a genetic nature and the use of informed consent from donors who accept the management of their DNA samples stored in the centre's bank are emphasized. The role of informed consent to find out patients’ opinions on what type of screening they want to be carried out, their desire to know the results of the screening and aptitude for future genetic data is also highlighted.

Introduction

The IVF/ICSI activity records of the National Activity Register-Spanish Fertility Society Register for 2016 and 2017 are presented.

Material and methods

An analysis was made using the data collected for cycles carried out in 240 Spanish centres in 2016, and 239 centres in 2017. The following cycles were studied: IVF/ICSI cycles with fresh own oocytes (2016: 54,024; 2017: 50,263); IVF/ICSI cycles with fresh donor oocytes (2016: 16,133; 2017: 16,774); cycles with cryopreserved embryos (2016: 27,202; 2017: 27,690); Pre-implementation Genetic Testing cycles (2016: 8,032; 2017: 9,268), and cycles with cryopreserved oocytes (2016: 7,769; 2017: 7,798).

Results

A total of 11,028 clinical gestations were obtained for IVF/ICSI with fresh own oocytes in 2016 and 9,710 in 2017, representing a pregnancy rate for fresh embryo transfers of 34.7 and 35.5%, respectively. In 2016, 18.7% of these gestations were multiple, with 16.6% in 2017. For IVF/ICSI with fresh donor oocytes, 12,616 fresh transfers were performed in 2016 and 11,440 in 2017. This resulted in 6,854 (54.3%) clinical gestations in 2016, of which 21.2% were multiple, and in 2017 there were 6,255 (54.7%) clinical gestations with 16.8% multiple gestations. In 2016, 855 (48.1%) gestations were obtained from 1,778 cryotransfers for Preimplantation Genetic Testing, and in 2017 2,953 (52.5%) gestations were obtained from 5,620 cryotransfers. The number of transfers carried out in 2016 with embryos from vitrified own oocytes was 607, and 6,166 with vitrified donated oocytes. In 2017, there were 560 transfers with vitrified own oocytes and 6,072 with vitrified donor oocytes.

Conclusions

The number of cycles with fresh and cryopreserved oocytes has come to a standstill, both for own and donated oocytes, except for Preimplantation Genetic Testing cycles, where the transfer of vitrified rather than fresh embryos is preferred.

Introduction

The data from the National Register of Activity in Assisted Human Reproduction (RNA – Register SEF), for artificial insemination during 2016 and 2017 are presented.

Material and methods

The data for conjugal and donor artificial insemination (AI-C and AI-D respectively) collected by the RNA – Register SEF during 2016 and 2017 were analysed and compared with data obtained in previous years. Participation was mandatory for Spanish assisted reproduction centres and annual aggregate data was collected by centre and in situ monitoring was carried out at random on data provided by more than 15% of the participating centres. A total of 36,463 cycles were analysed in 2016 (24,130 AI-C cycles and 12,333 AI-D cycles) and 34,964 cycles in 2017 (22,199 AI-C and 12,765 AI-D cycles).

Results

No significant differences were observed in the overall gestation rate per cycle, either for AI-C (2016: 13.0%; 2017: 12.6%) or for AI-D (2016: 20.4%; 2017: 19.6%). In 2016, 10.4% of the pregnancies obtained through AI-C were multiple pregnancies. Similar figures (10.7%) were obtained in 2017. Similar results were observed in AI-D, where the multiple gestation rate was 11.8% in 2016 and 9.9% in 2017. In pregnancies obtained with AI-C, 18.5% resulted in miscarriage in 2016, and 18.9% in 2017. With the donor technique, 17.2% resulted in miscarriage in 2016 and 17.7% in 2017.

Conclusions

Despite a slight increase in the number of participating centres, a decrease is observed in the use of AI-C, but this trend does not occur with AI-D.

Background

Nowadays, infertility is one of the most common problems in clinical medicine, as the number of couples that cannot conceive is increasing every year. The male factor contributes 40%-50% of the existing infertility and it has been observed that the seminal quality has been decreasing considerably in the last decades.

Aim

The main objective of this review focuses on the search for factors capable of affecting male fertility, determining what effects they produce in the body.

Material and methods

a bibliographic research was carried out in the main scientific journals in the field of assisted reproduction to identify the factors that alter male fertility and how they may be affecting it.

Results

It has been analysed 76 articles in this review. Among the main features that affect male fertility negatively, environmental compounds and lifestyle factors stand out. All of them can generate histomorphological, metabolic, endocrine, seminal and genetic alterations, although depending on the factor, they can affect more in some alterations than in others. Intake and environmental toxicants, health problems such as obesity or emotional disorders, as well as excessive physical exercise, act more frequently deregulating the hormonal system, decreasing testosterone levels and reducing the main sperm parameters (concentration, mobility and morphology). On the other hand, factors such as paternal age, intake toxicants, especially tobacco, and some environmental toxicants, such as bisphenol A or pesticides, act mainly generating breaks in DNA, mutations, chromosomal alterations or epigenetic changes.

Conclusion

All environmental and lifestyle factors analysed in this literature review have a negative effect on male fertility, which can be treated by improving life habits and/or through assisted reproduction techniques.

In medicine, there is a growing interest in predicting the individual risk of patients to develop a specific health problem or to predict their response to a treatment. Since in vitro fertilisation (IVF) an be physically and emotionally stressful, and as it is not free of health risks, the couples candidates for IVF should be well informed about the chances of success before each treatment cycle. A systematic review and a critical analysis of predictive models of ovarian response to stimulation and pregnancy after IVF is presented, showing, that in many cases the quality of these models is low. The inadequate methodology when developing a predictive model makes it difficult to apply in clinical practice. It is essential to develop, and to have methodologically appropriate predictive models, in order to optimise predictive capacity in assisted reproduction and achieve a true individualisation and personalisation in reproductive medicine.

Introduction

Women with poor (1-3 oocytes) or suboptimal response (4-9) to ovarian stimulation usually give immature oocytes. When this percentage is bigger than 50%, this situation is known as follicular asynchronism. We focused on women with advanced maternal age and suboptimal response to ovarian stimulation and the relevance that follicular asynchronism could have in ICSI procedure.

Material and methods

We have carried out a retrospective project, between January 2014 - December 2017, in which we have analyse 660 patients with advanced maternal age and who have been subjected to ICSI procedure with own and fresh oocytes. In this group, we found 199 patients who had a poor response and 161 patients with suboptimal response to ovarian stimulation. In the last group, 43 had follicular asynchronism and 418 patients had not this characteristic.

Results

In the group with poor response to ovarian stimulation (199), follicular asynchronism was showed in 25% of them, whereas patients with suboptimal response (461), only the 10% had this characteristic. We did not find significant differences between patients with follicular asynchronism or without this feature, related to fertilization rate or used embryos percentage. In order to obstetrical and gynaecological results, these are similar between groups. We did not realized differences in miscarriage rate (14,28 vs.35,24%) and it had not dissimilarity in labour rate / TE (27,27 vs. 22,44%; N.S.). We only found deviation in newborńs weight, which was fewer in patients without follicular asynchronism because in this group had more multiple gestation than in the group of patients with follicular asynchronism.

Conclusion

To sum up, the number of immature oocytes does not have effect on the rest of mature oocytes in the same cohort, when the patients are women with advanced maternal age and have a suboptimal response to ovarian stimulation, as long as, we only consider fresh transfer.