1. Full name: Nguyen Minh Duc 2. Gender: Male
3. Date of birth: 26th Feb 1985 4. Place of birth: Hanoi
5. Admission decision number: Decision No. 3972/QD-DHKHTN dated November 24th, 2016 of the Hanoi University of Sciences, Vietnam National University, Hanoi
6. Changes during training process: Decision to extend No. 567/QD-DHKHTN dated February 14th, 2020, Decision to extend No. 3178/QD-DHKHTN dated November 18th, 2021 and Decision to return PhD students to their workplace No. 1687/QD-DHKHTN dated June 1, 2023. Document requesting to return to training dated August 24th, 2023.
7. Official thesis title: Research on the human oocyte and embryo morphology in in vitro fertilization.
8. Major: Human and Animal Physiology. 9. Code: 9420101.04
10. Scientific supervisors: Main supervisor: Prof. Nguyen Dinh Tao
Secondary supervisor: Assoc. Prof. Trinh Hong Thai
11. Summary of the new findings of the thesis
- Fourteen abnormal features of oocyte morphology were identified in 10,116 mature oocytes collected from 788 patients undergoing in vitro fertilization (IVF) including: abnormal oocyte shape, dark ZP (Zona pellucida), abnormally shaped ZP, narrow PVS (perivitelline space), large PVS, granular PVS, fragmented PB (polar body), large PB, abnormally shaped PB, CLCG (Centrally located cytoplasmic granulation), HG (heterogeneous granulation), VAC (vacuole), SER (Smooth endoplasmic reticulum) and RF (refractile body). In 10,116 oocytes, the most common oocyte morphologies included HG (36.5%), granular PVS (30.5%), and fragmented PB (29.2%). In addition, HG (24.9%), fragmented PB (14.2%) and CLCG (14.2%) oocytes were commonly found in the group of oocytes with one abnormality. Abnormal PVS oocytes combined with abnormal PB (13.3%), abnormal PVS oocytes combined with abnormal CG (cytoplasmic granulation - including CLCG and HG) (21.3%), and abnormal PB oocytes combined with abnormal CG (21.4%) accounted for a high proportion in the group of oocytes with two abnormalities. These are the first analyses conducted in Vietnam on the distribution of oocyte morphology according to the number of abnormalities.
- Factors related to oocyte morphology included: total dose of FSH (Follicle stimulating hormone), methods for inducing final oocyte maturation, number of retrieved oocytes, and the mature oocyte rate. Among these factors, the possibility of abnormal oocytes was higher in the group with a total dose of FSH above 2500IU (international unit), the group using agonist trigger, the group with 15 or less retrieved oocytes, and the group with the mature oocyte rate of 75% or less. No statistically significant association was found between maternal age and oocyte morphology (p>0.05). The factors of total dose of FSH and agonist trigger related to oocyte morphology were also reported for the first time in Vietnam.
- Fertilization rate and quality of day two embryos according to some oocyte morphological features: Fertilization rate (83.3% - 90.6%) increased compared to the control group (73.2%) in the oocyte morphology groups: Oocytes with only large PVS (90.6%), granular PVS oocytes combined with fragmented PB (90.3%), granular PVS oocytes combined with HG (89.1%), fragmented PB oocytes combined with HG (83.8%). The rate of good day two embryos (68.7% - 75.0%) increased compared to the control group (49.7%) in the groups: granular PVS oocytes combined with fragmented PB (75.0%), granular PVS oocytes combined with HG (78.0%), fragmented PB oocytes combined with HG (68.7%). In contrast, the rates of fertilization and good day two embryos decreased in the group of only large PB oocytes compared to the control group by 44.4% and 25.0%, respectively. In addition, these rates of other morphological abnormal groups were not different from those of the control group.
- Effect of oocyte morphology on the rate of fertilization and quality of day two embryos: granular PVS oocytes increased the rate of fertilization. Granular PVS, fragmented PB and HG oocytes increased the rate of good day two embryos. On the contrary, large PB and CLCG oocytes reduced the fertilization ability. Other abnormal oocyte morphological groups had no effect on the rate of fertilization and quality of day two embryos.
12. Practical applicability:
- The results can be applied to help clinicians and embryologists predict the treatment results and counseling for infertile couples after the oocyte retrieval process; not all abnormal oocytes reduce the fertilization rate and the quality of day two embryos. In addition, the predictive value of oocyte morphology will provide more information for the subsequent ovarian stimulation.
- The total dose of FSH need to be considered and individualized when using exogenous FSH for each patient.
- The quality of day two embryos is influenced by oocyte morphology, so oocyte morphology can be considered as a criterion for the embryo selection if the embryo quality is equivalent.
13. Further research directions:
- Research the influence of oocyte morphology on blastocyst quality and other obstetric
outcomes.
- Research the influence of oocyte morphology on embryo morphokinetics, thereby examining
the relationship to the embryo genetic quality through preimplantation genetic testing.
14. Thesis-related publications:
[1]. Mai AD, Harton GL, Quang VN, Van HN, Thi NH, Thuy NP, Le Thi TH, Minh DN, Quoc QT. “Development and clinical application of a preimplantation genetic testing for monogenic disease (PGT-M) for beta thalassemia in Vietnam”. J Assist Reprod Genet. 2021. Feb;38(2):365-374. doi: 10.1007/s10815-020-02006-y. Epub 2020 Nov 20. PMID: 33216308; PMCID: PMC7884556.
[2]. Nguyễn Minh Đức, Đặng Tiến Trường, Nguyễn Thanh Tùng. “Ảnh hưởng của lưới nội chất trơn (SERs - smooth endoplasmic reticulum aggregates) đối với noãn trưởng thành đến kết quả của chu kỳ IVF”. Tạp chí Y học Việt Nam. 2022; 518 trang 143 đến 146.
[3]. Nguyễn Minh Đức, Trịnh Hồng Thái, Nguyễn Phan Cẩm Trang, Nguyễn Đình Tảo. “Bất thường bào tương noãn có hạt sậm ảnh hưởng đến kết cục của thụ tinh trong ống nghiệm”. Tạp chí Y học Việt Nam. 2024; 535(1B); trang 25-29.
[4]. Nguyễn Minh Đức, Trịnh Hồng Thái, Lại Thị Tuấn Việt, Nguyễn Đình Tảo. Các dạng hình thái noãn bất thường và ảnh hưởng của một số yếu tố đến hình thái noãn trong thụ tinh ống nghiệm”. Tạp chí Y học Việt Nam. 2024; 535(1B); trang 150-154.
https://doi.org/10.51298/vmj.v535i1B.8410.
[5]. Nguyen Thanh T*, Nguyen DM*, Dinh LT, Ngoc DL, Tien NS, Nguyen MP, Nguyen VP, Minh BT, Thi BTT, Nguyen DH, Trung NK. The Relationship Between Smooth Endoplasmic Reticulum Clusters in Metaphase II Oocytes and Embryological and Birth Outcomes in Infertile Couples. Int. J. Gen. Med. 2024; 17:3269-3277.
https://doi.org/10.2147/IJGM.S469626. *These authors contributed equally to this work
