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How can a varicocele affect male fertility?

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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.

A varicocele is a condition characterized by the presence of a varicose vein around the testicle. This anatomical abnormality is a recognized cause of male infertility because it can negatively impact both the quality and the quantity of sperm produced.1

While the spermatic cord is responsible for supporting the testes and housing the necessary blood vessels and ducts for reproductive function, the dilation of veins within this structure can lead to complications. When these veins become enlarged, they may cause pain, and in the context of fertility, they interfere with the optimal environment required for healthy sperm production. Surgical intervention, known as a varicocelectomy, may be performed to excise the dilated portions of the veins while preserving the essential blood supply to the testicle.21