Some Catholic History

Catholic Theology Concerning Birth Control:  The Catholic conclusion that birth control is sinful and priests must be celibat follows from the Garden of Eden scripture plus the concept of "Original Sin." All decedents are punished for the sin against God by Adam and Eve and not just in the original Jewish sense of expulsion from the garden of plenty, but by having Sex cast upon humans as punishment on earth. In this view sex did not exist in the perfection before Original Sin and will not exist in heaven. Sex on earth is an "inherited sin" and therefore sinful in all forms except for procreation in marriage.

    A New Theme Concerning Birth Control:  A more common reason used today for why birth control should be avoided is that pills and IUDs prevent implantation and kill embryos (which is bad because they are endowed with soul). But there are two technical complications with this point of view. First, full-time nursing is a form of birth control using the same hormones as the pill and subject to the same condition under which it prevents implantation. Schedule must be maintained for both.
   Also, the primary actions of the pill and of IUDs are to block ovulation and kill sperm - thus preventing nature's high loss of fertilized eggs. Except for the healthy young and fertile, not using birth control causes the natural loss of about 4 to 8 times as many fertilized eggs as abortion and hundreds to thousands times more than the very few that might be lost with birth control or even the Plan B morning-after pill.
    If the objective is to save embryos, the best way to do it is to encourage birth control for those not clearly fertile.
    If the objective is to argue against birth control, a more correct way to do it is to use standard original sin Catholic theology.