I was listening to the news the other day when a report came up about the bill that makes abortion illegal in South Dakota and I was struck by one of the sections of that law which says that life begins when sperm fertilizes egg.  I'm having trouble finding more specifics about the law but there is text of a similar piece of legislation from May 2004 with similar language.  I guess my question is does this law effectively make certain types of birth control illegal?  If life begins when sperm meets egg but fertilized egg is unable to plant itself in the uterus due to say an IUD or the pill does that constitute medicine or an instrument that causes an abortion, and if not, why?