The gemara acc. to our version asks a question whether a pregnant besulah (who either claims to be a besulah or is tested with the "barrel test") is permitted to a kohen gadol. But Rabbeinu Chananel explains (printed on 16 in vilna shas) the question based on the first pasuk in parshas Tazriah. The pasuk says the when a women is "mazriah" and gives birth to a male she is tameh for 7 days. R"C understands from this that she is only tameh if her pregnancy was through natural means of relations. The conclusion is that we assume she became pregnant in an ambati i.e. artificial insemination, and therefore does not have Tum'as leida. There is a tremendous nafkeh minah l'maseh from this. The halacha is that if a women does not have tumas leida then the baby is not given a milah on day 8. Meaning that if there is no tumas leida, then the bris does not push off shabbos. Therefore, any women who becomes pregnant through artificial insemination or in vitro fertilization (either from her husband or otherwise), the child would not receive his bris on the 8th day if it falls on shabbos. Obviously we do not pasken like R"C, but it is an interesting opinion.