Infertility and Intracytoplasmic Sperm Injection (ICSI)

Infertility is generally defined as a Time to pregnancy (TTP) of longer than 12 months among couples who engage in unprotected intercourse in the fertile days of the menstrual cycle, any specific threshold is arbitrary. The prevalence of infertility differs greatly from one country to another, being 15% globally, >30% in some developing countries, and 17-28% in industrialized countries. The term ‘implantation failure’ can be used to describe both patients who have never shown quantifiable signs of implantation such as increased levels of hCG, and those who have increased hCG production without later ultrasound evidence of a gestational sac. Intracytoplasmic sperm injection (ICSI) is a form of assisted reproductive technology in which a single sperm is injected into the cytoplasm of an egg in order to fertilize it. Complete fertilization failure following ICSI is an uncommon occurrence (1–3 percent), although it does occur even when spermatozoa appear to be normal. Furthermore, in some individuals, low to moderate fertilization (30 percent) has been reported in repeated ICSI cycles. Fertilization failure with ICSI is not the same as it is with traditional IVF technique. 60–90 percent of oocytes which showed a fertilization failure in traditional IVF are devoid of sperm nuclei, assuming that sperm ejection or penetration failure is the most common reason for the failure in fertilization process.