Biological factors affecting subzonal sperm microinjection results

Abstract

One hundred and sixteen couples with severe male factor infertility underwent 139 subzonal sperm microinjection cycles. In total, 1343 oocytes were microinjected, resulting in a fertilization rate of 24%, followed by a cleavage rate of 65%. In 26% of the zygotes, fertilization was delayed and embryos derived from these zygotes demonstrated a poor capacity for further growth and implantation. In 102 of 139 cycles (73%) embryo transfer was performed, resulting in 9 pregnancies. This study followed the fate of injected oocytes and early embryo development to investigate biological factors that influence the results of subzonal injection.