Semantics used in the nomenclature of in vitro fertilization, or let's all be more proper.
D001755:Blastocyst; D002970:Cleavage Stage, Ovum; D005307:Fertilization in Vitro; D005775:Gastrula; D006801:Humans; D009865:Oocytes; D010063:Ovum; D009626:Terminology as Topic; D015053:Zygote