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
Some patients suffer from complete immaturity of all eggs from conventional ovulation induction. The outcomes of the use of commercial in vitro maturation (IVM) medium to culture these immature oocytes 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.
In early clinical work, we found that immature oocytes can achieve a better clinical outcome after being cultured in vitro and fertilized with fresh sperm. Therefore, in this study, we wanted to further confirm this result and compare the outcome of in vitro matured eggs fertilized with fresh and old sperm.
To study the effect of sperm on the developmental potential of in vitro-matured oocytes in conventional culture.
Participants: The germinal vesicle (GV)-stage oocytes were donated by 28 patients who underwent intracytoplasmic sperm injection (ICSI) treatment due to male factors. Oocytes collection: Those GV-stage oocytes with a discernable germinal vesicle were donated and collected for this study. ICSI and IVM: GV-stage oocytes were randomly distributed to the old and fresh sperm groups. They were cultured for 24 h in the G-IVF-PLUS medium. The criterion of nuclear maturation was the extrusion of the first polar body. Then the number of MII-stage oocytes were conducted rescue intracytoplasmic sperm injection (RICSI) using old or fresh sperm.
None of the oocyte maturation, normal fertilization, and normal cleavage rates differed significantly between the two groups. The day-3 top-quality embryos and useful blastocyst rates of the old sperm group were significantly lower than those of the fresh group.
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.
For patients with poor oocyte maturity due to unknown reasons, the ICSI strategy could be recommended to be modified in the next cycle to provide a chance of the maturation of immature oocytes in culture in vitro.