Objective: To compare the effects on human oocytes of in vitro maturation periods of 28 hours and 36 hours.
Design: Retrospective analysis.
Setting: University teaching hospital.
Patient(s): A total of 48 infertile patients undergoing 55 cycles who volunteered for the experimental treatments.
Intervention(s): Immature oocytes were aspirated with use of transvaginal ultrasonography. Oocytes were matured, fertilized by intracytoplasmic sperm injection, and cultured for 2.5 or 3 days before being replaced into the uterus.
Main Outcome Measure(s): Oocyte maturation, fertilization and cleavage rates, and clinical pregnancy rate.
Result(s): Maturation of oocytes for either 28 hours or 36 hours before insemination resulted in similar rates of maturation, fertilization, and cleavage. The clinical pregnancy rate was similar in both groups (14%–15%).
Conclusion(s): Shortening the in vitro maturation period does not compromise subsequent embryonic development.