Objective: To test the hypothesis that intracytoplasmic sperm injection (ICSI) overcomes a high incidence of tripronucleate zygotes resulting from standard insemination in a previous cycle.
Design: A retrospective analysis of matched-pair cycles.
Setting: Assisted reproductive technologies (ART) program of Brigham and Women's Hospital.
Patient(s): Ninety-five patients with a > or = 20% incidence of tripronucleate zygotes in an IVF cycle with use of ICSI in a subsequent attempt.
Intervention(s): Cycles with either standard insemination or ICSI.
Main outcome measure(s): Incidence of diploid (2pn) and triploid (3pn) zygotes and number and quality of embryos obtained.
Result(s): Patient age, ampules of gonadotropin used, peak E2, number of follicles at hCG trigger, and total number of oocytes were all significantly higher in the ICSI cycles, but the number of mature oocytes did not differ. After ICSI, the percentage of 2pn was higher (65.0% vs. 34.1%) and the percentage of 3pn was lower (5.0% vs. 33.9%) than after IVF, and more diploid embryos were obtained with ICSI (5.5 +/- 3.7 vs. 3.4 +/- 2.2 [mean +/- SD]). There was no difference in embryo quality between the two groups.
Conclusion(s): ICSI appears beneficial in women with a high 3pn occurrence from IVF because it increases the number of diploid zygotes without affecting embryo quality.