This claims are referring to Bollinger's (2010) study, which estimated approximately 117 neonatal deaths per year from circumcision in the US, and then went on to say that this is higher than the annual number of deaths due to SIDS, choking, car accidents, etc. during the NEONATAL period. As the PP pointed out, this is only referring to deaths in the first month of life, but the stat is often not phrased correctly. In addition, I do not know how true the number actually is because I read the article and did not agree with the "common-sense calculations" used to come up with this estimate.
I have a pdf version of the article, but I think this is a web copy:http://www.faqs.org/periodicals/201004/2026622071.html
ETA: Yes, I'm quite sure that is the same article I read. It is an interesting read.