Complications of circumcision are rare in large series. It has been reported at 1–2%.
Most of the patients in these series are under one month old (neonates). Neonates have a lower complication rate after circumcision compared to older children.
Complications in circumcision for children older than one year have been reported at more than 6% in recent series.
What is the Best Age to Circumcise?
BMC Pediatrics 2012 DOI: 10.1186/1471-2431-12-20
Infancy presents the best age for circumcision. It is associated with substantially lower costs, lower risk of complications when performed by an experienced operator in a clinical or other appropriate setting, and lower lifetime risk of a variety of adverse conditions and infections.
Complications of Circumcision in Males: A Systematic Review
BMC Urol. 2010 Feb 16;10:2. doi: 10.1186/1471-2490-10-2
The review found a median complication frequency of 1.5% among studies of neonatal or infant circumcision, compared to 6% among studies of children aged one year or older.