you could also try the SOR resources here on BoS....
or do a search of the forums as this question has been asked before
for Catholic stuff (I wouldnt trust the suggested site above as its fundamental/very evangelical not Catholic and you asked for Catholic. Same principles yes, but you wont get the Catholic *specific* reasoning+resources ), try catholic.org.au and catholic.com
In a nutshell though, Catholic=a very big no to abortion due to the sanctity of life, not playing God etc etc etc