Most cases of female infertility are caused by problems with ovulation.Withoutovulation, there are no eggs to be fertilized.

Some signs that a woman is not ovulating normally include irregular or absent menstrual periods.

  • Ovulation problems are often caused by polycystic ovarian syndrome (PCOS).PCOS is a hormone imbalance problem which can interfere with normal ovulation.PCOS is the most common cause of female infertility.
  • Primary ovarian insufficiency (POI) is another cause of ovulation problems.POI occurs when a woman's ovaries stop working normally before she is 40.POI is not the same as early menopause.

Less common causes of fertility problems in women include:

  • Blocked Fallopian tubes due to pelvic inflammatory disease, endometriosis, or surgery for an ectopic pregnancy.
  • Physical problems with the uterus.
  • Uterine fibroids, which are non-cancerous clumps of tissue and muscle on the walls of the uterus.

Many things can change a woman's ability to have a baby. These include:

  • Age
  • Stress
  • Poor diet
  • Athletic training
  • Being overweight or underweight
  • Smoking
  • Excess alcohol use
  • Sexually transmitted infections(STIs)
  • Health problems that cause hormonal changes, such as polycystic ovarian syndrome and primary ovarian insufficiency

Many women are waiting until their 30s and 40s to have children. In fact, about 20 percent of women in the United States now have their first child after age 35. About one-third of couples in which the woman is over 35 have fertility problems. 

Aging decreases a woman's chances of having a baby in the following ways:

  • Her ovaries become less able to release eggs.
  • She has a smaller number of eggs left.
  • Her eggs are not as healthy.
  • She is more likely to have health conditions that can cause fertility problems.
  • She is more likely to have a miscarriage.