Electrical activation of oocytes after intracytoplasmic sperm injection: a controlled randomized study

Objective

To evaluate the electrical activation of oocytes in patients with previously failed or limited fertilization after intracytoplasmic sperm injection (ICSI) and in patients with possible failure of fertilization.

Design

Prospective randomized study.

Setting

A private IVF center in Egypt.

Patient(s)

Two hundred forty-six patients with severe oligoasthenospermia or nonobstructive azoospermia with total teratospermia or totally immotile spermatozoa were selected for the study. Patients who previously had total failure or limited fertilization after ICSI also were included.

Intervention(s)

Sibling oocytes were randomly divided after ICSI into two groups: the study group (n = 1,640) was subjected to electroactivation, and the control group (n = 1,435), to no electroactivation. Electroactivation was performed by using a double-square direct-current pulse. Embryo transfer was performed with the best available embryos.

Main Outcome Measure(s)

Fertilization rate, degeneration rate, and pregnancy outcome.

Result(s)

Two hundred forty-one ICSI cycles were included in the study. The fertilization rate was statistically significantly higher in the electroactivated group as compared with in the control group (68% vs 60%, odds ratio = 1.397, 95% confidence interval = 1.197 to 1.629). The oocyte degeneration rate was not statistically significantly different between the two groups (5.9% vs 4.9%, odds ratio = 0.96, 95% confidence interval = 0.73 to 1.26). In total, 112 clinical pregnancies resulted (pregnancy rate = 46.5%). Total fertilization failure occurred in 5 cycles in the control group, and none failed in the study group.

Conclusion(s)

Oocyte electroactivation after ICSI significantly improved the fertilization rate in severe oligoasthenoteratospermia and nonobstructive azoospermia.

Key Words: ICSI, fertilization, electrical activation, total fertilization failure