Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Although causes of female infertility can be classified as acquired versus genetic, female infertility is usually more or less a combination of nature and nurture. Also, the presence of any single risk factor of female infertility (such as smoking, does not necessarily cause infertility, and even if a woman is definitely infertile then the infertility cannot definitely be blamed on any single risk factor even if the risk factor is or has been present. Age, smoking, sexually transmitted infections, and being overweight or underweight can all affect fertility. Learn more about female infertility, its causes and treatments in the following pages.