Fertilization after standard in vitro fertilization versus intracytoplasmic sperm injection in subfertile males using sibling oocytes

Objective: To compare conventional IVF with ICSI in the subfertile male population using sibling oocytes. Results from males with isolated severe teratozoospermia also are analyzed.

Design: Prospective experimental study.

Setting: University based IVF clinic.

Patient(s): Group A: 18 patients with one or more abnormalities in count, motility, or morphology. Group B: 20 patients with isolated severe teratozoospermia (≤4% Kruger Strict Criteria).

Intervention(s): Ovulation induction, random allocation of sibling oocytes, and IVF or ICSI.

Main Outcome Measure(s): Fertilization rates (fertilization per cycle, fertilization per oocytes, and fertilization per couple) and embryo quality.

Result(s): In group A, fertilization occurred in 13 of 18 (72%) of IVF cycles and 17 of 18 (94%) of ICSI cycles. Overall, 69 of 120 (58%) oocytes fertilized after IVF, whereas 80 of 131 (61%) fertilized after ICSI. The mean (±SEM) percent of oocytes fertilized per couple was 44.6% ± 9.0% with IVF and 62.7% ± 5.6% with ICSI (not statistically significant). In group B, fertilization occurred in 18 of 20 (90%) cycles after IVF and 20 of 20 (100%) cycles with ICSI. Overall, 54 of 113 (48%) of the oocytes fertilized after IVF, whereas 82 of 124 (66%) fertilized with ICSI. The mean (±SEM) percent of oocytes fertilized per couple was 50.9% ± 7.1% with IVF and 66.6% ± 4.7% with ICSI. No statistically significant difference in embryo quality after IVF versus ICSI was demonstrated.

Conclusion(s): With severe teratozoospermia, ICSI results in higher fertilization rates than conventional IVF, without altering embryo quality. In our subfertile male population, there is a trend toward improved fertilization with ICSI, with less failed fertilization.