Number: 368 in vitro fertilization <desc> Description: Identify documents that discuss in vitro fertilization. <narr> Narrative: A relevant document will describe any aspect of the process of in vitro fertilization: uniting two human germ cells (sperm and egg) outside of the human body and in an artificial environment. Documents that describe related techniques, such as the freezing of eggs, sperm, or embryos for future implantation are also relevant.