Embryo density may affect embryo quality during in vitro culture in a microwell group culture dish.

PURPOSE: Culturing embryos in groups is a common practice in mammalian embryology. Since the introduction of different microwell dishes, it is possible to identify oocytes or embryos individually. As embryo density (embryo-to-volume ratio) may affect the development and viability of the embryos, the purpose of this study was to assess the effect of different embryo densities on embryo quality. METHODS: Data of 1337 embryos from 228 in vitro fertilization treatment cycles were retrospectively analyzed. Embryos were cultured in a 25 µl microdrop in a microwell group culture dish containing 9 microwells. Three density groups were defined: Group 1 with 2-4 (6.3-12.5 µl/embryo), Group 2 with 5-6 (4.2-5.0 µl/embryo), and Group 3 with 7-9 (2.8-3.6 µl/embryo) embryos. RESULTS: Proportion of good quality embryos was higher in Group 2 on both days (D2: 18.9 vs. 31.5 vs. 24.7%; p < 0.001; D3: 19.7 vs. 27.1 vs. 21.2%; p = 0.029; Group 1. vs. Group 2. vs. Group 3). Cell number on Day 3 differed between Groups 1 and 2 (6.8 ± 2.2; 7.3 ± 2.1; p = 0.004) and Groups 2 and 3 (7.3 ± 2.1 vs. 7.0 ± 2.0; p = 0.014). CONCLUSIONS: Culturing 5-6 embryos together in a culture volume of 25 µl may benefit embryo quality. As low egg number, position, and distance of the embryos may influence embryo quality, results should be interpreted with caution.

[First attempts in the introduction of cryopreservation of ovarian tissues]. / Kezdeti tapasztalataink a petefészekszövet-fagyasztás bevezetésével.

INTRODUCTION: The oncological treatment may damage ovarian function. To prevent this, it is possible to cryopreserve the ovarian tissue, and to keep the samples for long-term storage. The frozen-thawed tissue could be retransplanted after chemo- or radiotherapy. AIM: The aim of our study was to examine the effect of cryopreservation on the viability of ovarian tissue. METHOD: We analyzed the survival of frozen-thawed donated ovarian tissues. The quality of the follicles and hormone production in fresh and frozen-thawed samples were compared. RESULTS: Histological analysis showed that the number of viable follicles was reduced by 23% in the frozen-thawed samples. However, viable follicles still presented in post thawing ovarian tissues. Maximal estradiol production in frozen-thawed tissues was 908 pg/ml and hormone production was similar to the control tissues. The maximal progesterone production was 1.95 ng/ml post thawing, but these values were lower than the progesterone production of fresh tissues. CONCLUSIONS: The method of ovarian cryopreservation used in our laboratory was able preserve the viability of follicles in frozen-thawed ovarian tissues. Orv. Hetil., 2016, 157(49), 1947-1954.

Effect of hyaluronan-enriched embryo transfer medium on IVF outcome: a prospective randomized clinical trial.

PURPOSE: This prospective randomized study reports the effect of hyaluronan-enriched embryo transfer media on the outcome of in vitro fertilization and embryo transfer (IVF-ET) treatments. METHODS: A total of 581 IVF-ET cycles were included in this study. In the Hyaluronan (HA) group (n = 290), embryos were transferred from hyaluronan-enriched transfer medium. In Control group (n = 291), a conventional embryo transfer medium was used. RESULTS: There was no significant difference in clinical pregnancy rate (42.4 vs. 39.2%), implantation rate (23.3 vs. 23.2%), and delivery rate (31.0 vs. 29.2%) between the HA group and the Control group. The number of newborns was also similar in the two groups (111 vs. 110). However, birth weight was significantly higher in the HA group than in the Control group (3,018 ± 598 g vs. 2,724 ± 698 g, P = 0.001). Clinical pregnancy, implantation and delivery rates did not differ significantly between the HA and the Control group when cycles with advanced maternal age, previous IVF failures, low oocyte number or poor embryo quality were compared. CONCLUSION: Our results suggest that hyaluronan enrichment of the embryo transfer media does not seem to have any beneficial effect on IVF outcome. However, further study is needed to clarify the role of hyaluronan in the implantation process and on the birth weight.

Giant oocytes in human in vitro fertilization treatments.

PURPOSE: Giant oocytes are potential sources of chromosomal abnormalities and should thus never be used in in vitro fertilization and embryo transfer (IVF-ET) procedures. The presence of giant oocytes may indicate the efficiency of the ovarian stimulation and can refer to the quality of sibling oocytes. METHODS: IVF cycles performed between January 2008 and November 2013 (n = 1521) were divided into two groups: Giant Oocyte Group (GO Group) contained cycles with at least one giant oocyte in the cohort of the retrieved oocytes (n = 37), Normal Group contained cycles with no giant oocytes (n = 1484). In the second part of the study, cycles from GO Group and Normal Group were matched according to patient age, number of retrieved oocytes and stimulation protocol, and thus 30 pairs were formed. Clinical and embryological data were analyzed. RESULTS: The incidence of giant oocytes was 0.3 %. The average patient age was lower (33.5 ± 3.9 vs. 35.3 ± 4.9, p = 0.02); estradiol (E2) levels (1954 ± 903 vs. 1488 ± 909 pg/l, p < 0.01) and number of retrieved oocytes (12.7 ± vs 8.1 ± 5.1, p < 0.01) were significantly higher in the GO Group. There was no difference in clinical pregnancy rates (37.8 vs. 37.4 %, p = 1.00) between the two groups. No major differences in the embryo qualities were found. In the second part of the study, fertilization rate in the matched GO Group was lower (50.6 ± 21.9 vs. 61.9 ± 22.4 %, p = 0.04). Clinical pregnancy rates (36.7 vs. 36.7 %, p = 1.00) did not differ between the matched cycles. CONCLUSIONS: Our data suggest that the stimulation protocol does not affect the incidence of giant oocytes. Giant oocytes present in cycles with higher number of retrieved oocytes in younger women. The presence of these gametes does not refer to the quality of sibling oocytes and embryos, or the outcome of the treatment.

Intracytoplasmic sperm injection does not improve the outcome of IVF treatments in patients with advanced maternal age or low oocyte number: A randomized controlled trial.

INTRODUCTION: Intracytoplasmic sperm injection (ICSI) was introduced to achieve fertilization in cases of severe male factor infertility. However, ICSI is often used in cases of non-male factor infertility, such as advanced maternal age or low oocyte number, but the clinical benefit of the method in these indications has not been proven. MATERIAL AND METHODS: A prospective randomized study was conducted in a university clinic between 2018 and 2020. Patients with ≥40 years of age and/or ≤4 oocytes with non-sever male factor infertility were randomized into conventional IVF or ICSI groups. Fertilization rate, embryo quality, implantation, clinical pregnancy and live birth rates were compared. RESULTS: A total of 336 IVF cycles (169 conventional IVF and 167 ICSI) were involved in the study. The fertilization rate was higher in the conventional IVF group compared to the ICSI group (IVF: 61.7%, ICSI: 53.4%, P=0.001). Embryo development and morphology did not show considerable difference between groups. Implantation, clinical pregnancy and live birth rate were 13.1%, 24.3% and 11.4% in the conventional IVF and 10.4%, 19.0%, 12.0% in the ICSI group. The differences were not significant. Subgroup analysis showed a significantly better clinical outcome following conventional IVF when advanced maternal age was accompanied by low oocyte number (Implantation: 11.7% vs 2.6%, P=0.027; Clinical pregnancy: 18.5% vs 4%, P=0.020). DISCUSSION: A significantly higher fertilization rate, a tendency for higher clinical pregnancy rate was found in conventional IVF treatments compared to ICSI. When advanced maternal age was associated with low oocyte number, ICSI resulted in a substantially lower chance of fertilization and clinical pregnancy. These data suggest that ICSI offers no advantage over conventional IVF in terms of fertilization, embryo quality, implantation and pregnancy rates for couples with advanced maternal age or with low oocyte number.

Prospective-randomized study comparing clinical outcomes of IVF treatments where embryos were cultured individually or in a microwell group culture dish.

Culturing embryos together in a microdrop of media may improve embryo quality, based on the results of animal studies, however individual identification of the embryos in such a system is not possible. The microwell group culture dish contains 9 or 16 microwells with a minimal well-to-well distance and a specific well morphology that facilitates paracrine and autocrine effects. The microwell group culture dish enables individual identification of the embryos while providing the environment that comes with similar benefits as group culture. Our aim was to investigate whether embryo culture in the microwell group culture dish (Primo Vision Dish, Vitrolife) improves IVF outcomes compared to individual culture in human IVF treatment. Five hundred thirty-two IVF-ET cycles were enrolled in this prospective randomized study in a university hospital. IVF cycles were randomized into microwell group culture and individual culture groups. Primary outcome measure was clinical pregnancy rate and secondary outcome measures were embryo quality, fertilization, implantation, delivery and embryo utilization rates. Fertilization rate in ICSI cycles was significantly higher in the microwell group culture group (70.6% vs. 64.9%, P = 0.001). Clinical pregnancy rate was 50.8% in the group culture and 40.6% in the individual culture (P = 0.022). Live birth rate was 41.5% in microwell and 32.9% in individual culture (P = 0.0496). Embryo utilization rate was higher in microwell group culture than in individual culture (80.6% vs. 75.0%; P < 0.001). Microwell group culture has a beneficial effect on IVF outcome and it also allows following up individual embryo development.ClinicalTrials.gov: NCT01774006.