Marital Act Passes Original Sin?

[Shlomo]

“Behold, I was shapen in iniquity; and in sin did my mother conceive me.”
(Psalms 51:5)

I think the real question which hides behind the scenes is whether the act itself produces sin or it is just a transport which can in principle be different.

 

[HailStarofSea]

Logically, this seems to go toward ridiculous territory. For instance, are people conceived by in-vitro fertilization free from Original Sin?

From CASTI CONNUBII, Encyclical of Pope Pius XI.

‘… the very natural process of generating life has become the way of death by which original sin is passed on to posterity …’

vatican.va/holy_father/pius_xi/encyclicals/documents/hf_p-xi_enc_31121930_casti-connubii_en.html

Is this official Church teaching? The natural process would seem to be specific reference to the conjugal act. If it is ‘the’ way that original sin is passed on to posterity (our children), would children conceived outside of the marital act not need baptism?

Likely, it comes from St. Augustine, newadvent.org/fathers/1310.htm: Of Holy Virginity. It is interesting that the saint who is the exception to the rule on chastity is also the saint who most strongly values virginity.