Published online Mar 6, 2022. doi: 10.12998/wjcc.v10.i7.2166
Peer-review started: July 27, 2021
First decision: December 17, 2021
Revised: December 24, 2021
Accepted: January 25, 2022
Article in press: January 25, 2022
Published online: March 6, 2022
Processing time: 217 Days and 16.2 Hours
The outcomes of the use of commercial in vitro maturation (IVM) medium to culture immature oocytes obtained from conventional ovulation induction, followed by rescue intracytoplasmic sperm injection (RICSI), are not ideal. It is thus difficult to widely adopt this approach in clinical practice. Therefore, it is necessary to explore methods for improving the clinical outcome of IVM.
To study the effect of sperm on the developmental potential of in vitro-matured oocytes in conventional culture.
This was a retrospective study of patients whose immature oocytes were harvested from conventional oocyte stimulation cycles and underwent ICSI at our hospital between June 2018 and August 2020. RICSI was performed using sperm collected on the day of oocyte harvest (old) and sperm collected on the day of RICSI (fresh) and oocytes matured in vitro after 24 h of culture in conventional medium. The rates of in vitro oocyte maturation, normal fertilization, normal cleavage, day-3 top-quality embryos, and useful blastocyst formation were compared between the two groups.
In total, 102 germinal vesicle (GV)-stage immature oocytes were cultured in the old sperm group. In the fresh sperm group, 122 GV-stage immature oocytes were collected and cultured in vitro for 24 h. There were no significant differences in the general conditions of males and females between the two groups (P > 0.05). The oocyte maturation, normal fertilization, and normal cleavage rates of the old and fresh groups were 51.0% vs 55.7%, 61.5% vs 64.7%, and 93.8% vs 93.2%, respectively. None of the rates differed significantly (P > 0.05) between the two groups. However, the day-3 top-quality embryo and useful blastocyst rates of the old and fresh sperm groups were 16.6% vs 63.4%; 6.67% vs 34.6%, respectively. The day-3 top-quality embryos and useful blastocyst rates of the old sperm group were significantly lower than those of the fresh group (P < 0.05).
In vitro maturation with conventional culture medium combined with the use of fresh sperm collected on the day of RICSI is an easy-to-implement strategy for patients whose oocytes are completely or mostly immature.
Core Tip: Owing to the low implantation rate, in vitro maturation (IVM) is difficult to widely adopt in clinical practice. Therefore, there is an urgent need to explore methods for improving the clinical outcome of IVM. We studied the effect of sperm on early embryo development from in vitro-matured oocytes. Our results show that IVM with conventional culture medium combined with the use of fresh sperm collected on the day of rescue intracytoplasmic sperm injection is an easy-to-implement strategy for patients whose oocytes are completely or mostly immature.