Benefits
There are some real benefits for circumcision. The debate centers on whether the benefits are significant enough to warrant routine neonatal circumcision. Various professional groups have come down on either side of the issue.
Potential benefits include:
1. Decrease risk of urinary tract infections (UTIs).
This has been documented that neonatal circumcision reduces the incidence of UTIs in boys by 1/5 to 1/8 from ~1% to 0.2-0.12%. The Number Needed to Treat (NNT), i.e., circumcise would be 43-195 newborn boys to prevent one UTI.
Note: Special case. Infant boys with vesicoureteral reflux or hydronephrosis (documented postnatally, but suspected from fetal ultrasound showing ureteral or renal pelvic dilation) the incidence of UTI is eight times higher. A prophylactic neonatal circumcision is medically justifiable (but not absolutely necessary) if the parents so desire after informed consent.
2. Probable decrease risk for certain sexually transmitted diseases (STDs), including HIV, HPV, and syphilis.
As of 2007, there are three randomized controlled trials (RCTs) showing ~50% decrease incidence of HIV in adult African men, with a high prevalence of HIV in the population, if they are circumcised as an adult. It is controversial whether these data apply to neonatal circumcision in the U.S. and other countries with a low prevalence of HIV. There is non-RCT evidence of possible decrease of HPV (for men and women) and syphilis. No good evidence for benefit against herpes simplex and chancroid.
3. Prevents pathologic phimosis and paraphimosis.
Phimosis is a narrowed opening of the prepuce, preventing retraction of prepuce over and proximal to the glans, outside the normal developmental period of physiologic phimosis.
Paraphimosis is a painful constriction of the glans penis by phimotic band(s) that has been retracted proximal to the corona. Both are rare events and can often be treated by non-circumcision measures. See reference 5. Brown, MR, et al., Common office problems in pediatric urology and gynecology. Pediatric Clinics of North America. Oct 1997;44 (5):1091-1115 Figs. 3 and 4.
There is no good evidence that posthitis (inflammation of the prepuce) and balanitis (inflammation of the glans penis) are less frequent in circumcised vs. uncircumcised penises.