Catholic Priests used to perform abortions, and it was considered a lesser sin than fornication

A few years, the Irish Times' Women's Podcast looked into the historical relationships between the Catholic Church and abortion, based on extant old religious texts (mostly from Ireland). There's lots of interesting stuff here, but I found this the most fascinating:

The Penitential of Vinnian (often attributed to Finnian of Clonard) takes an even more permissive attitude to abortion.