In the United States, it is estimated that 6 percent of married women between 15 and 44 are infertile, according to the Centers for Disease Control and Prevention. 10.9 percent of all women between the ages of 15 and 44 have impaired fecundity.
Married women are considered infertile when they have not gotten pregnant after 12 months of unprotected sex with their husbands, explains the CDC.
Impaired fecundity refers to women who have had difficulty getting pregnant or carrying their babies to term, according to the U.S. Department of Health and Human Services. Maternal age, smoking, alcohol use, weight problems and a history of sexually transmitted infections negatively impact both fertility and fecundity.