Different opinions.
D004622:Embryo, Mammalian / Q000502:physiology*; D005260:Female; D005307:Fertilization in Vitro; D005615:Freezing; D006801:Humans; D008297:Male; D010063:Ovum / Q000166:cytology; D011247:Pregnancy; D013094:Spermatozoa / Q000166:cytology; D014021:Tissue Preservation