Male infertility

Certain types of chemotherapy or radiation can cause low sperm count.

Heavy drinking, using marijuana or tobacco, or taking certain prescription medications can interfere with male fertility.

Sometimes, male infertility happens because of genes or a family history of low sperm count. Klinefelter syndrome, a genetic condition in which a male has an extra X chromosome, can cause infertility.

Certain health conditions, like obesity and sexually transmitted infections (STIs), can contribute to infertility.

You may have a hormonal imbalance in your testicles or pituitary gland. Your pituitary gland releases hormones that stimulate your testicles to produce the hormone testosterone. Your testicles need sufficient levels of testosterone to make sperm.

An injury to your spinal cord or testicles can cause infertility in males.

Your body may produce antibodies that attack sperm. Antibodies can develop if your immune system detects sperm outside of your testicles. This sometimes occurs after an injury to your testicles, an infection, or a vasectomy.

Structural issues in your reproductive organs or sperm can cause problems with fertility. These include:

• Abnormal sperm shape or function that prevents sperm from swimming to and fertilizing an egg
• Birth defect that causes the absence of a vas deferens, the muscular tube that connects your testicles to your urethra
• Blocked ejaculation caused by a vasectomy
• Retrograde ejaculation, where semen flows into your bladder instead of through the penis
• Varicoceles, which are large veins in your scrotum