Infertility is the inability to become pregnant after one-year of unprotected intercourse. According to the Hormone Foundation, about 3 million couples in the U.S. are infertile. In 40 percent of cases, the problem is with the woman. Male factors are involved in about 30 percent of infertility. For 20 percent of couples, it is caused by a combination of problems in the woman and man. In 10 percent of couples, the cause is unknown.

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