There are many causes of infertility in women, and this list is not exhaustive.

Here are a few examples:

• ovulation abnormalities: absence of ovulation or poor-quality ovulation
• premature menopause
• Turner's syndrome
• adrenal gland abnormality
• obstruction of the fallopian tubes (due to salpingitis or adhesions, for example)
• endometriosis
• uterin fibroids
• PCOS-polycystic ovary syndrome (cysts on the ovaries as a result of hormonal imbalance)
• poor cervical mucus (which can be caused by infection)
• certain anti-cancer drugs
• thyroid problems
• diabetes
• sexually transmitted diseases
• kidney insufficience
• hypothalamo-pituitary/hypophyseal pathologies
• obesity
• Diethylstilbestrol
• psychological blockages
• dyspareunia (painful intercourse for the woman) likely to prevent penetration
• excessive thinness (anorexia)
• one of the main causes, which is social rather than medical, is the age at which people conceive their first child. The age of conception is increasing, as a result of greater use of contraception, late marriage, the higher number of sexual partners, and the focus on achieving a personal life plan ("settling down" in life) before conceiving a child. People also take their economical situation into account, which is delaying the decision to have a child. Fertility starts to decline from the age of about 30 and drops sharply after the age of 37.