To what extent is in-vitro fertilization (IVF) legitimate in Islamic law?

Contemporary jurists have discussed the issue of artificial insemination with specialized doctors. The decision can be summarized as prohibiting all methods of artificial insemination due to the mixing of lineages involved, with the exception of two methods permitted by the Islamic Fiqh Academy when necessary. These are: taking sperm from the husband and an ovum from his wife, fertilizing them externally, and then implanting the embryo in the wife's uterus; or injecting the husband's sperm into the appropriate place in his wife's vagina or uterus for internal insemination. This is while emphasizing the necessity of taking all required precautions.