Eating disorders can have people overweight, underweight and sometimes a normal weight. Body size has been related to several gynecological disorders. Higher risks of infertility have been found in both overweight and underweight women. To what extent being excessively under or overweight increases a woman?s risk for infertility is unknown. Women who are excessively underweight or overweight may be at increased risk of amenorrhea. Women need to have a certain amount of body fat in order to menstruate and conceive children.