I know this is going to sound dumb, but — how can there be a virgin birth without an immaculate conception?
The Immaculate Conception is not the conception of Jesus. It is the conception of Mary, who Catholicism teaches was preserved from sin in preparation for the conception of Christ. No flame wars from anyone, please, I am simply clarifying what IC is.
The Immaculate part refers to the Virgin Mary having been conceived without Original Sin. It’s nothing physical.