Catholics are not to circumcise: 
http://www.catholicsagainstcircumcision.org/  

Catholic Teachings on Circumcision (Printable Pamphlet)                             http://www.catholicsagainstcircumcision.org/Catholic_Brochure.pdf

The Morality of Circumcision According to the Catholic Church:
http://www.drmomma.org/2010/03/morality-of-circumcision-according-to.html