Icsi

Intracytoplasmic sperm injection (ICSI) is a laboratory technique used in assisted reproduction to fertilize an egg by injecting a single sperm directly into its cytoplasm. It is commonly performed as part of in vitro fertilization (IVF) cycles and is chosen when conventional fertilization is unlikely due to sperm quality or quantity.

The procedure begins with ovarian stimulation to produce multiple eggs, followed by egg retrieval. Sperm are prepared from the semen sample or retrieved surgically if necessary. A single healthy sperm is selected and injected into the oocyte using a microscopic needle. The resulting zygote is cultured in the laboratory and, if viable, embryos are transferred to the uterus. Extra embryos may be frozen for future use.

Indications include severe male factor infertility (low sperm count, poor motility or morphology), previous fertilization failure with conventional IVF, use of surgically retrieved sperm, or when preimplantation genetic testing or donor egg programs are involved. ICSI is also used in some cases where cryopreserved sperm are employed.

Outcomes depend largely on maternal age and the underlying infertility. When used for appropriate indications, ICSI yields pregnancy and live birth rates similar to conventional IVF, though it does not address non-male-factor infertility. Potential risks include fertilization of abnormal eggs or sperm, a small suggested increase in certain congenital anomalies or imprinting disorders in some studies, and the usual risks associated with IVF and embryo culture. Counseling and selection of good-quality embryos are important components of care.