The most common overall cause of female infertility is the failure to ovulate, which comprises in 40% of women with infertility issues. Not ovulating can result from several reasons, such as:

• polycystic ovary syndrome (PCOS)
• primary ovarian insufficiency (POI)
• advanced maternal age and poor ovarian reserve
• Endocrine disorders, such as thyroid disease or problems with the hypothalamus, which affect the hormones produced by the body so that there might be too much or too little of a hormone or group of hormones
• Lifestyle and environmental factors: overweight or underweight, excessive exercise, smoking, alcohol, caffeine amount intake, lower consumption of fruits and vegetables, body building supplements, occupational effect