As far as I know, the pill doesn't make a woman temporarily infertile. While on the pill, the woman still conceives but the embryo does not get implanted in the uterus. Instead, the woman's body flushes the embryo out.Augustus_Principe said:...a pill designed to make a woman temporarily infertile will inevitably cause some sort of permanent damage...
In other words, "birth control" pills are really abortion pills. They just don't tell you that because that would cause women to think twice about using them.
The reason drug companies get away with not disclosing this is because if the woman loses the embryo before it is implanted in the uterus, she is technically not considered to have been "pregnant." Therefore, it is technically accurate (although very deceptive) to say that the pill "prevents pregnancy."