abstract
- Fertilisation occurs through a complex and orderly sequence of changes in both the oocyte and the spermatozoon. Although mechanisms have evolved to protect spermatozoa from recognition by the immune system, there is evidence that a breakdown in protection can occur resulting in homologous or heterologous antisperm antibodies which can immobilise or agglutinate spermatozoa leading to infertility. Antisperm antibodies may affect the reproductive process by interfering with sperm survival and motility and sperm transport through cervical mucus. Fertilisation is also affected, and those oocytes that do fertilise go on to develop poorly. Antisperm antibodies appear to inhibit sperm attachment to and penetration of the zona pellucida. Immune recognition of sperm antigens, which are normally present on the surface of the embryo once fertilisation has occurred, may lead to abortion after implantation. Despite the adverse effects of antisperm antibodies on fertilisation and embryo development, acceptable pregnancy rates can be achieved with assisted reproductive techniques using sperm-washing to remove antibody and using a protein source other than female serum. Further study is necessary to understand the mechanism of immunological infertility and to evaluate newer techniques using micromanipulation of gametes to achieve fertilisation.