Did Abortion Do In Pagan Rome?

I think my entire adult life American public culture has been in a state of moral decay that invites comparison with Weimar Germany or pagan Rome: decadent cultures in decline and about to topple over. I'm not mocking: I need to re-read City of God, because the past four years the Church has seemed to me to be in precisely the position St. Augustine was in when he informed Rome that rather than blaming Christians for her troubles, she ought to wake up and see how the Christians were holding her together with water and a little rice paste.

Be that as it may, it seems to be Overseas Correspondent Week here at the blog, and herewith a little something from everyone's favorite Yorkshireman, Rueful Red: The Role of Infanticide and Abortion in Pagan Rome's Decline.

This is fascinating:
In addition to infanticide the Romans also practiced very effective forms of birth control. Abortion too was commonplace, and caused the deaths of large numbers of women, as well as infertility in a great many others, and it has become increasingly evident that the city of Rome never, at any stage in her history, had a self-sustaining population, and numbers had continuously to be replenished by new arrivals from the countryside. (For a discussion, see Rodney Stark, The Rise of Christianity: A Sociologist Reconsiders History (Harper Collins, 1996), pp. 95-128)
In his trenchant study of Rome’s social history during these centuries sociologist Rodney Stark wondered how the Empire survived as long as it did, and came to the conclusion that it did so only through the continual importation of barbarians and semi-barbarians. Far then from being a threat, the “barbarians” were seen as a means by which Rome might make good manpower shortages. The problem was that no sooner had the latter settled within the Imperial frontiers than they adopted Roman attitudes and vices.
Quite possibly, by the end of the first century, the only groups in the Empire that was increasing by normal demographic process were the Christians and the Jews, and these two were virtually immune from the contagion of Roman attitudes.
I've never read this before:
Taking this into account, several writers over the past few decades have suggested that Rome’s adoption of Christianity in the fourth century may have had, as one of its major goals, the halting of the empire’s population decline. Christians had large families and were noted for their rejection of infanticide. In legalizing Christianity therefore Constantine may have hoped to reverse the population trend.