Hesperian Health Guides

What Causes Infertility?

Infertility in a man

The main causes of infertility in a man are:
  1. He does not produce enough sperm. Or his sperm cannot swim to the woman’s tubes or to fertilize the eggs.
  2. He had mumps after puberty that harmed his testicles. He may still come (ejaculate), but the semen has no sperm in it.
  3. His sperm cannot leave his penis because he has scars in his tubes from a sexually transmitted infection (STI).
  4. He has a swelling of the veins in his scrotum (varicocele).
  5. Problems during sex because:
    • his penis does not get hard.
    • his penis gets hard but does not stay hard during sex.
    • he comes too quickly, before his penis is deep in the woman’s vagina.
  6. Illnesses such as diabetes, tuberculosis, and malaria.

Infertility in a woman

Infertility caused by infection can be prevented. See Pelvic Inflammatory Disease and How to Prevent STIs.

The main causes of infertility in a woman are:
  1. She has scarring in her tubes or inside her womb. Scarring in the tube can prevent the egg from moving through the tube, or the sperm from swimming to the egg. Scarring in the womb can prevent the fertilized egg from attaching to the wall of the womb. Sometimes a woman gets scarring but does not know it because she does not feel ill. But years later she learns she is infertile.
Infertility in the woman
1. blocked tube
a woman's reproductive parts, showing sperm that cannot reach the egg because the tube is blocked
2. ovary does not produce an egg
a woman's reproductive parts, showing no egg in the tube
3. fibroids
a woman's womb with a growth in it

Scarring can be caused by:

  • an infection from an untreated STI that goes up into the womb or tubes (pelvic inflammatory disease or PID).
  • unsafe abortion or problems in childbirth that caused damage or infection in the womb.
  • unclean conditions when an IUD is put in that caused an infection.
  • problems from an operation of the vagina, womb, tubes, or ovaries.
  1. She does not produce an egg (no ovulation). This can be because the body does not make enough of the needed hormones at the right time. If her monthly bleedings are less than 25 days apart, or more than 35 days apart, she may have a problem with ovulation. Sometimes a woman does not produce eggs if she loses weight very quickly, or if she is too fat.
  2. She has growths in her womb (fibroids). Fibroids can prevent conception or make it difficult to carry the pregnancy.
  3. Illnesses such as HIV, diabetes, tuberculosis, and malaria can also make a woman less fertile.
This page was updated:17 Apr 2019