internal fertilization

...IVF generally refers to the union of sperm and eggs, i.e. fertilization, taking place outside the animal's body, usually in the water in which the animal lives. However, in mammals (e.g. humans), IVF refers to the internal fertilization that naturally occurs in these animals, i.e., the internal fertilization that occurs inside the female's body when a male and a female mate (sexual intercourse between a man and a woman), which is artificially performed outside the body, and to the general manipulation of such fertilization. Research on IVF in this sense not only elucidates the mechanisms of fertilization and embryo development, such as the development and metabolism of fertilized eggs, but also serves clinically as a basis for the development of contraception methods and the prevention of congenital abnormalities, and has also been put to practical use as a treatment for tubal infertility (test tube babies).

*Some of the terminology that mentions "internal fertilization" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

…体外受精とは，一般には精子と卵子の合体，すなわち受精がその動物の体外，ふつうにはその動物のすむ水中で行われることをさす。しかし哺乳類など(たとえばヒト)で体外受精という場合には，これらの動物で自然に行われている体内受精internal fertilization，すなわち，雌雄の交尾(男女の性交)によって雌(女性)の体内で行われる体内受精を人為的に生体外の場で行わせること，およびそのような受精を行わせる操作一般をさす。　このような意味での体外受精の研究は，受精卵の発育，代謝など受精･胚発生の機構を明らかにするだけでなく，臨床的には避妊方法の開発や先天性異常の発現予防への土台となり，さらに卵管不妊に対する治療法(試験管ベビー)として実用化されている。…

※「internal fertilization」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