Embryo Transfer Technique Research Articles

Live birth rates after blastocyst transfers performed by fellows

To evaluate live birth rates following embryo transfer performed Reproductive Endocrinology and Infertility fellows compared to attending physicians. Retrospective Cohort Study. Institutional Review Board approval was obtained. Women undergoing blastocyst transfer between 1/2015 and 1/2018 were reviewed. Cycle characteristics and outcomes were compared between embryo transfers performed by fellows and attending physicians. A sample size of 750 embryo transfers was required to detect a 10% difference between groups, with 80% power and alpha of 0.05. A total of 940 blastocyst transfers were included; 254 performed by five fellows and 686 performed by ten attending physicians. There were no differences in the mean age, anti-mullerian hormone (AMH) levels or rate of preimplantation genetic testing for aneuploidy (PGT-A) testing between groups (Table). The afterload technique was utilized more frequently by fellows, 95.2% (242/254) vs. 87.8% (602/686), P=0.0004. A stylet was used less frequently by fellows, 0.4% (1/254) vs. 4.5% (31/686), P=0.0008. The pregnancy rate in the fellow group was not significantly different from the pregnancy rate in the attending group; 72.8% (185/254) among fellows versus 67.6% (461/686) among attending physicians, p= 0.27. There were also no significant differences in the live birth rate between groups, 51.6% (131/254) versus 49.4% (339/686) respectively, P=0.61. After controlling for embryo transfer technique and stylet use, there remained no difference in pregnancy outcomes. The average pregnancy rate among fellows performing their first 20 embryo transfers was 67.4% (58/86), and was no different from the average pregnancy rate among attending physicians, 67.6% (461/686) P=1.0. Embryo transfer success rates were not different between fellows and attending physicians. Barriers to fellowship training in embryo transfer should be evaluated and addressed, as there was no compromise in pregnancy rates, even in the first twenty embryo transfers performed.Table 1Group Characteristics (N=940 transfers)Fellow ET (N=254)Attending ET (N=686)p-valueAge (SD), yr34.1 (3.4)34.1 (3.6)1.00AMH (SD), ng/mL3.9 (3.1)3.8 (3.3)0.68% PGS testing22.0% (56/254)22.6% (155/686)0.93% Fresh Transfer41.3% (105/254)34.4% (236/686)0.06Afterload technique95.2% (242/254)87.8% (602/686)0.0004Stylet0.4% (1/254)4.5% (31/686)0.0008Blood on catheter tip4.3% (11/254)6.8% (47/686)0.17Embryo Retained0% (0/254)0.3% (2/686)1.0# Embryos Transferred (SD)1.2 (0.5)1.3 (0.5)0.1Pregnancy Rate72.8% (182/254)67.6% (464/686)0.27Miscarriage Rate18.9% (48/254)16.8% (115/686)0.44Live Birth Rate51.6% (131/254)49.4% (339/686)0.61 Open table in a new tab

Optimising the Outcome of Embryo Transfer

In vitro fertilisation (IVF) is a complex procedure, the success of which is dependent on several factors at every step of the process. Despite major advances, successful implantation rates in IVF remain low. Aside from the status of the embryo and endometrium, embryo transfer (ET) plays a major role in implantation. There are numerous variables in ET that are causative factors for IVF success. In this article, the authors discuss whether the stage at which (cleavage versus blastocyst) ET occurs; a fresh or frozen ET; and the technique of ET affects the results of an assisted reproductive technology cycle. Blastocysts had higher implantation potential than cleavage-stage embryos and it was also observed that extended embryo culture was not related to increased adverse obstetric and perinatal outcome. Though freezing has several advantages over fresh cycles, one must remember that evidence is still lacking for its use in all patients. Elective cryopreservation of all embryos with transfer in subsequent frozen ET cycles may be requited in cases at risk of developing ovarian hyperstimulation syndrome, women undergoing preimplantation genetic screening or preimplantation genetic diagnosis for genetic analysis, polycystic ovarian syndrome patients, and those who have high progesterone levels on the day of human chorionic gonadotropin, but to date it is debatable whether a freeze-all strategy will benefit normal and poor responders. For an optimal ET technique, the use of soft catheters and performing the process under ultrasound guidance will improve results by making it less traumatic, standardised across centres, and more technically precise.

Frequencies of genotypes and alleles of rs41256848 in the LHCGR gene in the population of black-and-white holsteinized cattle

Embryo transfer technique is one of the key in accelerated reproduction of cattle. One of the most important stages is the selection of donor cows that are most sensitive to the procedure of hormonal stimulation of ovulation. One of the promising genetic markers of the reproductive status of cattle is currently the gene encoding the luteinizing hormone / choriogonadotropin receptor (LHCGR). One of the SNP in the LHCGR gene of cattle has already been described in the literature as associated with the number of oocytes and the quality of embryos - rs41256848 (c.1401G> T, p.Trp467Cys). The purpose of this work was to estimate the frequencies of genotypes and alleles of this substitution in the population of Black-and-White holsteinized cattle (190 cows). Genotyping was performed by PCR-RFLP method. In the studied population of cattle, the frequency of the G allele associated with higher rates in the total number of oocytes and the number of embryos survived after transplantation, as well as with the least number of unfertilized oocytes, is 63.2%.

Decontamination of genetically modified mice strains by embryo transfer for obtaining SPF colonies in a Brazilian animal facility

The introduction of new strains of mice in specific pathogen-free (SPF) animal facilities should be performed carefully to avoid breaking sanitary barriers. To meet this need, animals should be rederived to reduce infection risk and thus avoid research interference caused by loss of animal health status and welfare. The objective of this study was to implement mice embryo transfer in the laboratory mouse facility of the Department of Immunology at the Institute of Biomedical Sciences/University of São Paulo, Brazil. Embryo transfers were performed to rederive genetically modified mouse strains with undefined sanitary status, received from different research and educational institutions. Fertilized eggs at two-cell stage were obtained by natural means and transferred into the oviducts of SPF pseudo-pregnant female mice. All surgical procedures were performed under aseptic conditions. A total of 625 embryos were transferred into therecipients. 148 pups were born, of which 140 were reared. Viruses, bacteria and intestinal protozoa were eliminated using this technique. The improvement in the microbiological status of mice allowed their expansion in our SPF facility. With these results, we can stimulate the use of embryo transfer technique between rodent facilities in Brazil and thus encourage the distribution of better models to our scientific community.

Minimally Invasive Embryo Transfer and Embryo Vitrification at the Optimal Embryo Stage in Rabbit Model.

Assisted reproductive techniques (ARTs), such as in vitro embryo culture or embryo cryopreservation, affect natural development patterns with perinatal and postnatal consequences. To ensure the innocuousness of ART applications, studies in animal models are necessary. In addition, as a last step, embryo development studies require evaluation of their capacity to develop full-term healthy offspring. Here, embryo transfer to the uterus is indispensable to perform any ARTs-related experiment. The rabbit has been used as a model organism to study mammalian reproduction for over a century. In addition to its phylogenetic proximity to the human species and its small size and low maintenance cost, it has important reproductive characteristics such as induced ovulation, a chronology of early embryonic development similar to humans and a short gestation that allow us to study the consequences of ART application easily. Moreover, ARTs (such as intracytoplasmic sperm injection, embryo culture, or cryopreservation) are applied with suitable efficiency in this species. Using the laparoscopic embryo transfer technique and the cryopreservation protocol presented in this article, we describe 1) how to transfer embryos through an easy, minimally invasive technique and 2) an effective protocol for long-term storage of rabbit embryos to provide time-flexible logistical capacities and the ability to transport the sample. The outcomes obtained after transferring rabbit embryos at different developmental stages indicate that morula is the ideal stage for rabbit embryo recovery and transfer. Thus, an oviductal embryo transfer is required, justifying the surgical procedure. Furthermore, rabbit morulae are successfully vitrified and laparoscopically transferred, proving the effectiveness of the described techniques.

Comparison of Embryo Transfer Techniques in Assisted Reproductive Technology (ART) Cycles [35K

INTRODUCTION: Different transfer techniques have been developed to optimize the embryo transfer process and maximize the probability of pregnancy after transfer. The purpose of this study is to compare the afterload (AL) embryo transfer technique and the post-mock (PM) embryo transfer technique. METHODS: We designed a retrospective cohort study which included women who underwent an autologous, fresh or cryopreserved embryo transfer (ET) between 01 July 2013 and 01 September 2016 at our academic center. Embryo transfer was performed with either the afterload technique (AL) or the immediate post-mock (PM) transfer technique. The primary outcome of interest was ongoing pregnancy rate (OPR) defined as fetal cardiac activity on first trimester ultrasound. This study was approved by the Tripler Army Medical Center Department of Clinical Investigation Scientific Review Committee and Institutional Review Board. RESULTS: There was no significant difference in OPR between patients that underwent AL transfers and PM transfers (AL 51%, PM 57%; P=.378). Ongoing pregnancy rate for frozen embryo transfers was superior for AL transfers compared to PM transfers (AL 68%, PM 31%; P=.005). Ongoing pregnancy rate was superior with the PM technique for fresh embryo transfers (AL 43%, PM 63%; P=.002). Ongoing pregnancy rate decreased with age in the AL cohort, but not in the PM cohort (P=.004). CONCLUSION: There appears to be no overall difference in OPR between AL and PM transfer technique. However, with vitrified embryos, the AL technique demonstrated a higher OPR, and with fresh embryos, the PM technique resulted in a superior OPR.

Sexual maturity of mares and prospects for shortening the intergenerational period in horses

The aim of the study is to present current knowledge on the mechanisms regulating puberty in mares and the possibility of shortening the intergenerational period in horses through modern animal reproduction biotechnology. The study discusses fetal sex recognition in horses by means of ultrasound, pre- and postnatal development of mare gonads, oogenesis and folliculogenesis, as well as the process of selection and elimination of oocytes. It also describes the role of gonadotropins, ovarian hormonal activity and morphological changes occurring during sexual maturation. It has been shown that about 37% of mares attain sexual maturity in the first year of life. It has also been documented that one-year and two-year-old fillies produce normal embryos that can be used for transplantation and give offspring. It has also been proved that embryos can be produced in vitro from oocytes of juvenile mares. There is hope that acquiring preantral follicles from the ovary and their in vitro culture until the oocyte reaches full maturity for fertilization will permit us to obtain embryos and offspring from mares, including those sexually immature. These methods, combined with in vitro fertilization and embryo transfer techniques, have already made it possible to obtain normal embryos and even live-born offspring in other mammals.

Training on transabdominal ultrasound guidance during embryo transfer and proficiency evaluation of training

Background: Embryo transfer (ET) is the crucial and final step in in-vitro fertilisation (IVF) process which has major impact on IVF outcome. ET technique has been standardized at present and done under ultrasound guidance. But there are no standardised steps described for the transabdominal ultrasound guidance during ET. Aims: To define the steps of transabdominal ultrasound guidance during ET using a training module; to evaluate the proficiency and learning curve of training; and to assess the impact on trial ET performance after training. Settings and design: A prospective study was conducted in a tertiary assisted reproductive technology (ART) centre, northern India between August 2018 and February 2019. Materials and methods: Ultrasound guidance during trial ET was evaluated for 12 doctors who participated in the study on 234 patients. Ultrasound guidance evaluation included scores for USG assessment of trajectory, catheter type prediction, difficulty prediction, ultrasound visualisation during trial ET and trial ET performance. Transabdominal ultrasound guidance training was given to all doctors after 10 pre-training evaluations followed by post-training evaluations. Pre- and post-training mean scores for each doctor and overall were compared using SPSS-21. Results: Mean scores showed improvement in all parameters, including trial ET performance for the doctors included in study. Overall, these differences were statistically significant. six doctors (50%) were declared trained in transabdominal ultrasound guidance during trial ET. Conclusion: The training module was effective in defining the steps of transabdominal ultrasound guidance during trial ET and improving the trial ET performance.

Developments of reproductive management and biotechnology in the pig.

This review aims to describe changes in production environment, management tools and technology to alleviate problems seen with the present hyperprolific sow model. Successful parturition in the pig includes the possibility to express adequate maternal behaviour, rapid expulsion of piglets, complete expulsion of placenta, elimination of uterine contamination and debris, neonatal activity and colostrum intake. We focus on management of large litters, including maternal behaviour, ease of parturition, colostrum production, piglet quality parameters and intermittent suckling. There are also some interesting developments in technology to assess colostrum and immune state of the piglet. These developments may be utilized to improve the success rate of reproductive management around farrowing, lactation and after weaning. We also discuss new insights in how to examine the health of the mammary gland, uterus and ovaries of hyperprolific sows. Finally, we assess the latest developments on breeding and technology of hyperprolific sows, including artificial insemination (AI), real-time ultrasound of the genital tract and embryo transfer (ET). We conclude that 1) for the sow to produce sufficient colostrum, both the behavioural and physiological needs of the sow need to be met before and after parturition. Furthermore, 2) new ultrasound and biopsy technology can be effectively applied for accurate diagnosis of inflammatory processes of the udder and uterus and timing of AI regarding ovulation to improve insemination efficiency. Finally, 3) developments in cryopreservation of germ cells and embryos appear promising but lack of valid oocyte collection techniques and nonsurgical ET techniques are a bottleneck to commercial ET. These latest developments in management of parturition and reproductive technology are necessary to cope with the increasing challenges associated with very large litter sizes.

Use of two new formulations as bovine embryo manipulation solution.

This study aimed to evaluate the effect of two Embryo Manipulation Solutions (EMS and EMS supplemented) in maintenance of the viability of embryos, initially using structures derived from mice (first phase). Next, the efficiency of these solutions in routines of bovine embryo transfer was evaluated (second stage). Mice embryos were used in the stages of early blastocyst, and compact morula grades I and II. These embryos were initially randomly distributed and maintained for four hours in three solutions: Modified phosphate buffered saline (PBS; Control); EMS (treatment 1), and EMS supplemented (treatment 2). Subsequently, they were cultured in TCM 199 medium and evaluated in terms of total number of cells, morphometric characteristics, ultra structural aspects, detection of cell apoptosis, and quantification of Hsp70.3 gene expression. In the second phase, these same solutions were tested in the transfer of quality I and II bovine embryos (excellent and good). These embryos were transferred fresh to 58 recipients. The results showed that the total number of cells in embryos expanded blastocyst (ExB), the number of apoptotic cells, the cell, nuclear, nucleolar diameter and the nucleus/nucleolus ratio was similar among the treatments. The pregnancy rate shown on second phase was also similar. However, the EMS supplemented expressed more Hsp70.3 than EMS. The expression of Hsp70.3 was also greater for embryos in EMS than that of EMS supplemented. The McII embryos, EMS and EMS supplemented samples also expressed more Hsp70.3 compared to control embryos. In conclusion, the tested solutions can be used in routine embryo transfer techniques, replacing modified PBS solution as an effective media in maintaining embryo viability.

Impact of heat stress on the reproduction of farm animals and strategies to ameliorate it

ABSTRACTAnimals are susceptible to heat stress under tropical environmental conditions. Exposure of growing male and female animals to severe heat stress during summer adversely affects their growth and reproductive traits, reduces the resistance to diseases and induces infertility in farm animals and represents a major source of economic loss to the livestock sector. During the summer season, animals usually suffer from summer sterility due to prevailing hot and humid conditions. In female animal’s age at puberty, estrous signs, ovulation time, ova quality, conception rate, embryonic development, embryo size, embryo weight and hormonal balance are affected by exposure to heat stress. The most sensitive to heat stress are growing ovarian follicles. Heat stress–induced changes in growing follicles can be expressed later as compromised maturation and developmental capacity of the ovulating oocyte. In males, sex hormone levels, spermatogenesis, temporary sterility, libido, ejaculate volume, macroscopic as well as microscopic semen characteristics in an ejaculate are affected, and sperm abnormalities and dead sperm increase by exposure to the heat stress. Various heat stress amelioration technologies have evolved to circumvent the fertility reduction in dairy cattle and other livestock animals. New breakthroughs such as estrus synchronization, embryo transfer technique, cryopreservation of gametes and genetic manipulation, nutraceuticals (feed additives, pre and probiotics) and managerial changes may exist to improve summer fertility. This review summarizes the most up-to-date information on the effects of heat stress on the male and female reproduction especially under tropical conditions.

110 First ovum pickup-in vitro-produced lidia breed calves using Lidia breed recipients: influence of age and state of the recipients and in vitro-produced embryos on pregnancy rates

We previously demonstrated the success of in vitro embryo production (IVP) in Lidia breed cattle (Gamarra Lazo et al. 2017 Reprod. Fertil. Dev. 30, 187). As in other species, the success of IVP is linked to the birth of calves from this technique. In the Lidia breed, an important factor to consider is the use of Lidia recipients in order to keep the temperament characteristic of this breed to next generations. The aim of the study was to produce ovum pickup (OPU)-IVP calves in the Lidia breed and to assess the effects of recipient and embryo related factors (status of the recipients; development stage of IVF embryos) on pregnancy rate following embryo transfer. Ovum pickup-IVP embryos from Lidia breeds were produced by a standard protocol (Gamarra Lazo et al. 2017 Reprod. Fertil. Dev. 30, 187). Numbers of blastocysts and expanded blastocysts were recorded on Day 7. A total of 27 blastocysts (B) and 34 expanded blastocysts (EB) of excellent quality (grade 1 according to IETS classification) were selected for fresh transfer. All embryos were transferred to Lidia breed recipients (heifers or cows) by a single operator under similar environmental and field conditions. Recipients were synchronized by subcutaneous insertion of an ear implant of 3.3mg of Norgestomet (Crestar®, MSD, Courbevoie, France) for 9 days. Two days before implant withdrawal, 0.5mg of Cloprostenol (Estrumate®, MSD) was injected. No oestrous detection was performed and synchronized females were selected as recipients when they presented a well developed corpus luteum at Day 9 after implant withdrawal (Day 6 to 7 after the expected oestrus). Blood samples were collected from recipients to determine pregnancy status using the bovine pregnancy associated glycoprotein (Idexx, Westbrook, ME, USA) 50-60 days after transfer. Pregnancy rates were analysed by chi-square analysis to compare results between heifers and cows and between B and EB embryo stages. The overall pregnancy rate after transfer of IVP fresh embryos from Lidia breed averaged 41.0% (n=25). A higher pregnancy rate was achieved in cows compared to heifers [51.2% (21/41) v. 20.0% (4/20) respectively, P<0.05]. There was no difference in pregnancy rate between grade 1B [37% (10/27)] and EB [44.1% (15/34)] embryos (P>0.05). Surprisingly, these results suggest that Lidia breed cows are the best recipients for OPU-IVP embryos. This may be related to the limited feasibility of manipulating the uterine horn during the embryo transfer in Lidia breed heifers, which have a low weight (less than 280kg) and present a narrow rectum diameter. It has been also observed that the cervix is very thin and difficult to cross, thus increasing the stress and potentially inflammatory and immune products secretion. Development stage of embryos did not affect pregnancy rate. To our knowledge, no OPU-IVP Lidia breed calves have been reported previously following transfer into Lidia breed recipients. In the current work, 13 OPU-IVP Lidia breed calves were born. Therefore, we confirmed the possibility of applying OPU-IVP and embryo transfer techniques in this breed within a genetic program.

Non-surgical embryo transfer technique and recipient mare pregnancy rate

Equine embryo transfer was first described by Japanese scientists in 1972, with successful embryo survival achieved by transvaginal ultrasound-guided injection of the embryo into the uterus of recipient mares.1,2 Earlier...

Prospective Randomized Trial Comparing Embryo Transfers of Cases with and without Catheter Rotation during Its Withdrawal

Objective: To compare embryo transfer (ET) technique based on catheter rotation during its withdrawal in cases with unexplained infertility in a prospective, randomized trial (NCT03097042). Methods: Two hundred intracytoplasmic sperm injection (ICSI) patients undergoing ET with cleaving or blastocyst-stage fresh embryos were randomized into 2 groups: cases with (n = 100), and without (n = 100) catheter rotation during its withdrawal. Groups were matched for age and some clinical parameters. A soft catheter was used to transfer a single embryo with catheter rotation during its withdrawal in the study group and without rotation in the control. The use of a stiff catheter or tenaculum was not needed in any case. Groups were compared in terms of cycle characteristics and clinical pregnancy rates. Results: Pregnancy rate was significantly higher in the study group (41 vs. 26%, p = 0.04). Clinical pregnancy rate was also significantly higher in the study group (39 vs. 25%, OR 1.9 [1.1–3.5], p = 0.05). On the other hand, the ongoing pregnancy rate was similar between the 2 groups (33 vs. 23%, p = 0.2). Conclusion: Catheter rotation during its withdrawal may be associated with increased pregnancy and clinical pregnancy rates; however, the difference in ongoing pregnancy rates did not reach statistical significance.

Reproduction in domestic ruminants during the past 50 yr: discovery to application.

The study of reproductive physiology in domestic ruminants has progressed from the whole animal to the molecular level in an amazingly short period of time. The volume of information on this subject is enormous; therefore, we have focused on domestic ruminants, with an emphasis on cattle. To date, artificial insemination (AI) is perhaps the most powerful technique that reproductive physiologists and geneticists have provided the livestock industry for genetic improvement. Early efforts to establish AI as a tool were initiated in Russia around 1899 and since that time major advances in methods of semen collection, evaluation of male fertility, cryopreservation of sperm, sex-sorted semen, and estrous cycle control have occurred. The preceding advances not only led to the widespread use of AI, but also contributed to our fundamental understanding of ovulation control, timing of insemination, gamete biology, and cryopreservation. In regards to anestrus, our understanding of the concept of neuroendocrine control of the pituitary gland and the role of steroid feedback led to the Gonadostat Theory, which proposes that onset of puberty is due to a decrease in the negative feedback of gonadal steroids over time. Subsequent studies in prepuberal and postpartum sheep and cattle established that a short luteal phase frequently precedes the first normal length cycle that is accompanied by estrous expression. This observation led to the common practice of treating prepuberal heifers and anestrous postpartum cows with a short-term progestin treatment (e.g., Controlled Internal Drug Release) to induce normal estrous cycles. In domestic ruminants, fertilization rate is high (85% to 95%); however, significant embryonic mortality before or around the time of maternal recognition of pregnancy (MRP) reduces the pregnancy rate to a single breeding. Significant effort has been directed at determining the time of MRP, the signal for MRP, as well as elucidating the physiological, cellular, and molecular dialogue between the conceptus and uterine environment. Advancements have now led us to the ability to edit the genome to alleviate disease and possibly improve production traits. In summary, major advancements in our understanding of reproductive biology have stemmed from efforts to establish the AI and embryo transfer technique and reduce the negative impact of anestrus and embryonic mortality in domestic ruminants.

Current perspectives on in vitro maturation and its effects on oocyte genetic and epigenetic profiles.

In vitro maturation (IVM), the maturation in culture of immature oocytes, has been used in clinic for more than 20 years. Although IVM has the specific advantages of low cost and minor side effects over controlled ovarian stimulation, the prevalence of IVM is less than 1% of routine in vitro fertilization and embryo transfer techniques in many reproductive centers. In this review, we searched the MEDLINE database for all full texts and/or abstract articles published in English with content related to oocyte IVM mainly between 2000 and 2016. Many different aspects of the IVM method may influence oocyte potential, including priming, gonadotrophin, growth factors, and culture times. The culture conditions of IVM result in alterations in the oocyte or cumulus cell transcriptome that are not observed under in vivo culture conditions. Additionally, epigenetic modifications, such as DNA methylation or acetylation, are also different between in vitro and in vivo cultured oocytes. In sum, current IVM technique is still not popular and requires more systematic and intensive research to improve its effects and applications. This review will help point our problems, supply evidence or clues for future improving IVM technique, thus assist patients for fertility treatment or preservation as an additional option.

The use of multiple ovulation, embryo cryopreservation and embryo transfer techniques to facilitate movement of genetic material between countries

The objective of the study was to evaluate the use multiple ovulation and embryo transfer techniques in an indigenous Greek dairy breed of sheep. We stimulated selected donor ewes of the Karagouniko breed to produce large numbers of embryos after the induction of multiple ovulations by gonadotropin treatment (superovulatory response). A total of 50 Greek Karagouniko ewes were synchronised into oestrus using progestagen pessaries and superovulated for embryo transfer using ovine FSH. Six days following laparoscopic insemination with fresh semen ewes were flushed surgically and embryos collected. Subsequently, the embryo recovery, along with embryo cryopreservation, embryo survival and quality were assessed. The Karagouniko donor ewes achieved a mean ovulation rate of 11.9 (SE. 0.89). The ova Recovery rate was 80,9% and 87,6% of the ova recovered being fertilised. A total of 327 (77,5%) of the viable embryos were assessed as being of sufficient quality for cryopreservation. The embryos ranged from late morulae to expanded blastocyst and were frozen via a 3-step process in 1.5 M ethylene glycol following repeated washing and trypsination. Cryopreserved embryos were frozen and then transported to Scotland, UK. There, embryos were thawed rapidly and re-hydrated via a 2 step sucrose/ethylene glycol gradient. A total of 92.4% of embryos frozen remained suitable for transfer semi-surgically into synchronized Scottish Blackface ewes. 183 embryos were transferred in total with a 66.1% survival rate. The survival rate of frozen thawed blastocysts(75%) was significantly greater than (P<0.01) that for morulae (48%). It was concluded that MOET could be successfully applied in Greek dairy breeds of sheep as a means for genetic improvement. Frozenembryos could be a successful medium for the transportation of ovine genetic material from and to Greece, however, most likely the choice of embryonic stage for cryopreservation is crucial.

Genetic variability in equine GDF9 and BMP15 genes in Arabian and Thoroughbred mares

Abstract In horses, multiple ovulation resulting in implantation of multiple embryos is adverse. However, understanding the mechanisms underlying initiation of multiple ovulation (MO) is advantageous and is related to an increase in efficiency of embryo transfer techniques. It has been postulated that MO may have a genetic background. Two major genes: bone morphogenetic protein 15 (BMP15) and growth and differentiation factor 9 (GDF9) are considered to play a crucial role in folliculogenesis and controlling the ovulation rate. Thus, the aim of the presented study was to identify the variation within equine BMP15 and GDF9 genes to verify their potential role on spontaneous, repetitive multiple ovulations in mares. In addition, variation screening of investigated genes in population of Thoroughbred and Arabian breeds was performed together with establishment of transcript abundance of BMP15 and GDF9 genes in equine ovarian tissue. Sanger sequencing of Arabian and Thoroughbred mares divided according to ovulation rate, revealed occurrence of 3 SNPs in BMP15 and STS in GDF9 genes. The PCR-RLFP and statistical analysis indicated that none of the genotype frequencies were significant in any breeds and none of them were claimed as functional according to ovulation rate. Furthermore, evaluation of transcript abundance by RT -PCR of both genes in ovarian tissues showed that expression of both genes was similar but GDF9 was significantly expressed in growing follicles with 21-30 mm diameter and in ovarian parenchyma, which suggest their potential role in folliculogenesis.

Intrauterine air impairs embryonic postimplantation development in mice

ObjectiveAlthough most embryologists load air bubbles into the catheter along with embryos during embryo transfer, the effects of these air bubbles on embryo transfer success rate are not clear. Study designAir bubbles were nonsurgically injected into unilateral uterine horns of mice to demonstrate the negative effects of intrauterine air bubbles on embryonic development. ResultsOur data showed that when air bubbles are nonsurgically injected into unilateral uterine horns of pregnant 4days mice the litter size is significantly decreased. Four days after the introduction of air, abnormal decidua and dead conceptuses were detected in the uterine horns receiving the air bubbles. In addition, intrauterine air also significantly impaired murine embryo transfer success rates, and induced an increase in endometrial capillary permeability and decidualization in mice on day 4 of pseudopregnancy. These results strongly indicated that the air bubbles loaded into embryo transfer catheters to bracket the embryo-containing medium may have negative effect on embryonic implantation and development. ConclusionsIntrauterine air impaired murine embryonic postimplantation development, and this provided some clues for improving embryo transfer techniques in human.

Training fellows to perform embryo transfers: a standard protocol giving excellent live birth rates

Embryo transfer (ET) technique plays a critical role in determining the success of an IVF cycle and should be an important component of fellow training. Yet, many REI fellows graduate performing few or no ETs. We have developed a standard protocol for fellows to perform ETs. The purpose of this study was to determine if live birth rates differ between attending physicians and fellows using a standard protocol. Retrospective analysis IVF cycles performed at an academic medical center between 7/1/2005 and 12/31/2015 were identified. Cycles without a documented pregnancy outcome or ET physician were excluded. All fellow transfers were done with a Wallace catheter using the afterload technique while the attending physician performed abdominal probe ultrasound to ensure proper embryo placement. Data were analyzed by attending physician versus fellow status. All outcomes were evaluated using t-tests, chi squared or regression analysis. A total of 2,477 cycles meeting criteria were identified. Attending physicians performed 2,001 transfers, while fellows performed 476. Attending physicians transferred a larger proportion of grade 1 embryos (62% vs. 56%, p= 0.013), while fellows transferred a larger proportion of grade 2 embryos (37% vs. 30%, p= 0.009). There were otherwise no differences in cycle characteristics between attending physicians and fellows (Table 1). Additionally, there were no differences in per cycle live birth rates between attending physicians and fellows (30% vs. 28%, p= 0.422); this relationship remained true even after adjusting for differences in morphology grading. When data were analyzed by fellowship year, there remained no differences in live birth rates between groups. In particular, the per cycle live birth rate among first year fellows was 30% compared to 32% among attending physicians (p= 0.653). Our data show that there are no differences in live birth rates associated with embryo transfers performed by attending physicians versus fellows. Furthermore, mastery of proper embryo transfer technique is a skill that can be effectively learned during one’s first year of fellowship training. We therefore demonstrate that our decade long practice of training fellows to perform embryo transfers does not compromise pregnancy or live birth rates.Tabled 1Patient Cycle CharacteristicsAttending PhysiciansFellowsAge3636BMI2423Stimulation days1010Oocytes retrieved1212Embryos transferred2.12D5 transfers14%16%Clinical Pregnancy40%42%Miscarriage8%7%Live birth30%28% Open table in a new tab