The reasons for infertility can involve one or both partners. In general:
- In about one-third of cases, the cause of infertility involves only the male.
- In about one-third of cases, the cause of infertility involves only the female.
- In the remaining cases, the cause of infertility involves both the male and female, or no cause can be identified.
Causes of male infertility
Causes of male infertility may include:
- Abnormal sperm production or functiondue to various problems, such as undescended testicles, genetic defects, health problems including diabetes, prior infections such as mumps, trauma or prior surgeries on the testicles or inguinal region. Enlarged veins in the testes can increase blood flow and heat, affecting the number and shape of sperm.
- Problems with the delivery of spermdue to sexual problems, such as premature ejaculation, semen entering the bladder instead of emerging through the penis during orgasm (retrograde ejaculation), certain genetic diseases, such as cystic fibrosis, structural problems, such as blockage of the part of the testicle that contains sperm (epididymis), or damage or injury to the reproductive organs. Men who have previously undergone a vasectomy and desire a return of fertility will also need to either have the vasectomy reversed (see ‘vasectomy reversal’ below) or have sperm retrieved through a surgical procedure for use in assisted reproductive techniques.
- Overexposure to certain chemicals and toxins,such as pesticides, radiation, tobacco smoke, alcohol, marijuana, and steroids (including testosterone). In addition, frequent exposure to heat, such as in saunas or hot tubs, can elevate the testicular temperature, impairing sperm production.
- Damage related to cancer and its treatment,including radiation or chemotherapy. Treatment for cancer can impair sperm production, sometimes severely. Removal of one testicle due to cancer also may affect male fertility