What causes infertility in women?

Ovulation problems

Most cases of infertility are caused by problems with ovulation. Ovulation is the release of the egg from the woman’s ovary, which occurs once per month, about 12–14 days before the first day of each menstrual period. Without ovulation, a woman cannot become pregnant. Ovulation problems can be caused by hormone imbalances from a variety of causes.

Blocked fallopian tubes

Although less common, blocked fallopian tubes can also cause female infertility. To become pregnant, a woman’s egg must move from the ovary through the fallopian tube to the uterus. The fallopian tube is where the egg and sperm meet and fertilization occurs. If the fallopian tube is blocked due to infection, surgery, or other problems, then sperm cannot reach the egg to fertilize it.

Other less common causes of fertility problems in women can include physical problems with the uterus, or uterine fibroids, which are non-cancerous tumors made of fibrous tissue and muscle cells that develop on the walls of the uterus.

What decreases a woman’s chance of becoming pregnant?

  • Being age 30 or older (at age 40 there is a big drop in the chance of being able to become pregnant).
  • Smoking.
  • Heavy alcohol use (more than three to four drinks a day).
  • Stress.
  • Poor diet.
  • Diabetes.
  • Too much athletic training.
  • Being significantly overweight or underweight.
  • History of certain sexually transmitted diseases (STDs), especially ones that have caused pelvic inflammatory disease (PID).
  • History of endometriosis (growth of uterine tissue outside of the uterus).
  • Health problems that cause changes in the hormones in a woman’s body, such as thyroid problems or polycystic ovary syndrome (PCOS).
  • Radiation treatment and/or chemotherapy for cancer.