"WHO | Infertility" infertility infertility «Infertility definitions and terminology» «Infertility definitions and terminology» infertility Definitionen «Infertility definitions and terminology» "WHO | Infertility" World Health Organization "WHO | Infertility" «Infertility definitions and terminology» 従来の「不妊」の定義 «Infertility definitions and terminology» WHO Infertility «Infertility definitions and terminology» a glossary with multiple existing definitions infertility infertility