Problems with the ovaries or lack of regular ovulation, which is the development or release of a healthy egg. These may be caused by endocrine disorders such as Polycystic Ovarian Syndrome (PCOS) that can result in irregular menstrual cycles including prolonged, infrequent or lack of periods; infertility; or recurrent miscarriages.
Problems with the fallopian tubes, the uterus, or other pelvic organs.
Examples include:
Damage to the fallopian tubes that affects the movement of the egg into the uterus
Endometriosis, where tissue normally found on the inside of the uterus is found on the outside of the uterus and can cause scarring and anatomical abnormalities that disrupt the menstrual cycle.
Fibroids, or uterine tumors, forming the muscle of the uterus and distorting the uterine cavity and interfere with conception.
Hormonal abnormalities, where certain imbalances can affect the ability to produce a healthy egg.
The woman’s age. Experts now believe that a woman’s ability to conceive begins to decrease approximately 10 years before the onset of menopause, which varies from woman to woman, but in general starts at age 35.