Intracytoplasmic sperm injection ICSI

FI 1). Besides oocyte quantity, oocyte quality is also an important factor. Although immature oocytes can be fertilized in vitro, the incidence of pregnancy per transfer of immature eggs is half that of mature eggs (P8, V5). Oocytes with cytoplasmic abnormalities can be inseminated using intracytoplasmic sperm injection (ICSI), but almost never lead to pregnancy (K3). 

These observations are important for understanding the mechanism by which fertilization triggers the onset of development, and relevant to the successful fertilization of human oocytes in cases of assisted conception, particularly since the introduction of intracytoplasmic sperm injection (ICSI). Whereas normal sperm - oocyte fusion in humans is always followed by a train of periodic Ca spikes, ICSI only sometimes elicits similar Ca oscillations (Tesarik, Sousa Testart, 1994). Much attention is focused on the function of periodic Ca spikes in successful fertilization by ICSI (Taylor, 1994 Tesarik, 1994). In some species, such as sea urchin, a single Ca spike at fertilization induces zygote development, while a larger number of spikes may be needed in mammalian species. The pattern of Ca " spiking associated with successful fertilization may thus vary from species to species. 

In extreme conditions, when no fertility of thawed sperm is maintained, intracytoplasmic sperm injection (ICSI) into a recipient oocyte can be... 

Intracytoplasmic Sperm Injection (ICSI) Procedure by which a single spermatozoa is inserted directly into an individual ovum in a laboratory. 

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