Circumcision is the surgical removal of the foreskin, the tissue covering the head of the penis. It is an ancient practice that has its origin in religious rites. Today, many parents have their sons circumcised for religious or other reasons. A circumcision is usually performed within 48 hours of birth by an obstetrician or pediatrician in the hospital, or on the eighth day after birth for the Jewish ritual. The most clear-cut medical benefits of circumcision are a four-to-tenfold decrease in the risk of urinary tract infections during the first year of life, and a threefold reduction in the risk of penile cancer among adult men. However, UTIs and cancer of the penis are rare. Studies also show a somewhat higher incidence among uncircumcised men of sexually transmitted diseases, including syphilis and HIV.