Abstract: 36

IS BIOLOGICALLY DEAD SPERM REPRODUCTIVELY DEAD?

Ali Ahmady^{1 *}, Soon-Chye Ng^{1 *}
Department Obstetrics & Gynaecology, National University of Singapore, Singapore, Singapore ¹

Two main structural deficiencies occur in the infertile men's ejaculate resulting in sperm death: primary necrosis due to infectious and consequent inflammation, and apoptosis due to anatomical or hormonal disorder. The aim of this investigation is to study the developmental capacity of sperm at various levels of death. The sperm were subjected to various treatments to induce death at the different levels (cellular and molecular) prior to injection into the ooplasm. We demonstrate that with dead sperm, the key point in the fertilization process is the activation of the oocyte, by injection of cytosolic sperm factor in our experiments. Fertilisation rate was 17.5% when dead sperm were injected into the oocyte, compared to 55.0% in control group (live sperm). The fertilisation rate was increased to 62.8% in cellularly dead sperm, 65.4 % in early molecularly dead sperm, 61.3% in totally dead sperm and 57.1% in totally dead with severe DNA damage sperm when the oocyte was activated with cytosolic sperm factor. Blastocyst development and live foetuses were 58.5% and 36.4%, 56.3% and 31.4% in live-intact sperm and cellularly dead sperm groups respectively. These rates were reduced to 52.7% and 26.7% in early molecularly dead sperm, 24.6% and 18.2% in totally dead sperm groups respectively. This study contributes to a better understanding of the fertilizing ability of dead sperm. These findings can be applied clinically to patients with necrospermia or very severe oligospermia and in wildlife research where dead sperm from rare species can be used to regenerate young, and hence propagate the species. Also implied is the possible contribution of sperm DNA strand breakage resulting in early pregnancy loss.

    This abstract is being presented on Sunday, August 1 at 8:00 AM to 10:15 AM at CUB 2nd Floor Ballroom.