How does intracytoplasmic sperm injection help when sperm counts are very low?

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Diagram showing the female reproductive system with labeled ovaries, fallopian tubes, uterus, and vagina, alongside hormone pathways and the process from ovulation to fertilization and early embryo development. — infertility Major structures and hormones involved in the initiation of pregnancy. Also seen, at right, is the development of an egg cell (ovum) from follicle to embryo.

Intracytoplasmic sperm injection (ICSI) is a specialized medical procedure designed to assist couples when a male partner has a very low sperm count or sperm that are otherwise unable to fertilize an egg naturally.1

The process works by bypassing the natural fertilization barriers:

Direct Injection: A single sperm is selected and injected directly into the cytoplasm of an egg that has been retrieved for in vitro fertilization (IVF).1
Sperm Retrieval: In cases where an obstruction prevents sperm from moving through the genital ducts, sperm can be collected directly from the epididymis using a technique called microsurgical epididymal sperm aspiration (MESA).1
Implantation: Once the eggs are successfully fertilized in the laboratory, they are placed into the woman’s uterus to facilitate pregnancy.1

This method, first used successfully in 1992, provides a viable path to conception for men who would otherwise be unable to fertilize an egg due to significant limitations in sperm quantity or function.1