In order for a couple to become pregnant, at least four things have to happen:
- A woman must produce and release a healthy egg from one of her ovaries (ovulation).
- A man must produce viable sperm which can successfully fertilize the woman’s egg (fertilization).
- The egg must travel through a fallopian tube toward the uterus (transportation).
- The fertilized egg must attach to the inside of the uterus (implantation).
Low sperm count or abnormal sperm function may be caused by different things. These include:
- Undescended testicles
- Genetic defects/DNA damage
- Diabetes
- Prior bacterial or viral infections such as mumps or adenovirus
- Trauma or prior surgeries on the testicles or inguinal region
- Enlarged veins (varicoceles) in the testes that can increase blood flow and heat, both of which affect the number and shape of the sperm
- Exposure to chemicals like pesticides, radiation, and chemotherapy
- Alcohol use, marijuana use, and tobacco smoke
- Steroid use
- Overexposure to heat (such as in saunas and hot tubs)
- Surgical removal of one of the testicles due to cancer
In addition, there can be problems with the delivery of sperm and subsequent fertilization due to any of the following:
- Premature ejaculation
- Damage or injury to the reproductive organs
- Semen entering the bladder instead of emerging through the penis during orgasm (retrograde ejaculation)
- Certain genetic diseases (such as cystic fibrosis)
Men who have previously had a vasectomy and wish to father a child have two choices. They either need to have the vasectomy reversed or have sperm retrieved through a surgical procedure as part of assisted reproductive techniques.
