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...refers to the inability to have a live birth even after two years or more, excluding the period of contraception after marriage. It is said to occur in about 10% of all couples, and is distinguished as follows: when a couple has never become pregnant, it is called "primary infertility," when a couple has already had a child but has never become pregnant, it is called "secondary infertility," and when a couple becomes pregnant but is unable to have a live birth, it is called "infertility." There are many different causes of infertility, and they are broadly divided into "male infertility" and "female infertility" depending on whether the problem is in the man or the woman, with the ratio said to be 2 to 3....

*Some terminology explanations that mention "infertility" are listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…結婚後の避妊期間を除いて，2年以上経過しても生児を得られない状態をいう。全夫婦の約10％にみられるといわれ，1度も妊娠していないものを〈原発性不妊〉，すでに子どもはいるが，その後妊娠しないものを〈続発性不妊〉といい，妊娠はするが生児を得られない場合を〈不育症infertility〉と呼んで区別している。不妊の原因は種々たくさんあり，男性，女性のいずれにあるかで〈男性不妊〉と〈女性不妊〉に大別され，その比率は2対3といわれている。…

※「infertility」について言及している用語解説の一部を掲載しています。

出典｜株式会社平凡社世界大百科事典 第２版について | 情報