Some thoughts from a former Protestant.
First of all, I agree that, while the larger problem is the abortion rate because it results in the death of a human being, the cause is our society’s obsession with sex, money, comfort, and generally doing what we want.
I think self identity of Catholics causes part of this problem. I think there are more Catholics in name only because being Catholic is almost cultural, like saying you are of German heritage or something. That said, once people grow up and fall away from the faith of their family, young protestants will probably call themselves athiests, agnostics, or just ignore the issue, while Catholics carry the title with them for life. Therefore, there may actually be more self-described Catholics having sex outside of marriage than of self-described Protestants.
There is also the birth control issue. Without understanding the full reasons (Theology of the Body and such) behind it, many Catholics will not use birth control because they understand it to be “bad” but continue to have sex. Non-catholics, however, see birth control as no problem and will use it. This cuts down on the number of unwanted pregnancies by non-Catholics as opposed to Catholics. However, the numbers are skewed because hormonal birth controls are abortifacients. Therefore, when these abortions of fertilized eggs are considered, I am sure the numbers begin to even out.
An unmarried Catholic woman may feel a lot more pressure to abort because she never want anyone to know she has been pregnant. She may be sexually active because she no longer believes the faith she was raised in but her parents and grandparents are strong in the faith. Or she may be a true Catholic who messed up. Either way, adoption becomes a scary option because she would have to actually go through a pregnancy and people would know she had been sexually active. This is actually a phenomenon I saw at a non-Catholic Christian college as well - there can only be one Virgin Mary.
So I think it is a combination of Catholics in name only, Catholics following church teaching on birth control but not on sex, and fear of retribution.
(By the way, I personally believe that anyone who takes the time to understand the Catholic church’s teaching on birth control, sex, abstinence, family planning, sin, grace, and redemption will find that it is not as irrational, controlling, or just plain mean as society would have you believe - why else would I be here if I thought so?)
