if abortion , like all other sins , is an act of not trusting in God, as the ultimate source of our existence and whose will sustains everything of us , then the events in the sitution mentioned by O.P are easily seen…
There is the selfcenterdness to only see things in the human , worldly way which is mostly of the enemy …
And hence the cheapening of sex as only an avenue of pleasure and not sacred…
When God, in His Mecry choose to send His eternal soul to such a situation, it could help the parents to get out of the selfcenterdness and realise what true love and mercy is - seeing each person with the God given dignity and potential …
Seems, when such teens who made mistakes turn to His ways , somehow , there is the flow of grace …those parents seem to mature up …become more disciplined …
Where as , with wrong choices , it furthur undermine their basic identity as a child of God , in whom they can trust, even when it is tough and thus to be able to see His mercy at many levels …
So, it is no wonder that they would not trust a stranger to care for the child …
There is the element of presumption - that God does not care about our lives being holy - otherwise , there would not have been the premarital sex…
The lies of these self centered fears can be used , by sharing how such a choice would damage themselves at many levels ; there is plenty of info on this topic on the internet .
Problems in relationships, depression, eating disorders (and all related problems - diabetes, high blood pressure , joint problems ) ,addictions cancers , heart attacks…who knows if even such modern plagues like attention defict, autism and such are related to such massive psychic wounds …
Good thing more persons , esp. at the political level are recognisig these truths and turning away from their misguided earlier efforts to protect women !
May God abundanly bless efforts of such groups as the Priests for Life !