Infertility is usualy defined as not being able to get pregnant after at least one year of trying to conceive. Women who can get pregnant, but then suffer miscarrigaes are also consiered infertile. About 1 in 6 couples, about 15%, have infertility and have trouble getting pregnant or carrying a baby to term.
85% of couples trying to coneive are able to become pregant in the first 12 months of trying. After another 36 months, 50% of the remaining 15% are able to coneive spontaneously.
Many times people have no idea they are infertile until they have trouble conceiving. This is because there are very few symptoms of infertility except for lack of pregnancy. Sometimes women will notice irregular menstrual periods or men will have hormone problems that cause symptoms. The cause of infertility can vary greatly as there are so many different components of the reproductive system that must work in sync for conception and full term pregnancy to take place.