CHICAGO -- Circumcising newborns causes virtually no medical harm, but offers practically no benefit, either, according to a study that tries to put solid numbers on the risks.
Researchers found that infants who undergo the procedure have only a 1-in-476 chance of complications.
By comparison, there is a 1-in-20 chance of complications from refractive eye surgery, an increasingly common elective procedure, according to the American Academy of Ophthalmology.
Circumcision is thought to prevent urinary tract infections and penile cancer. But the researchers found that for every complication from circumcision, only six urinary tract infections are prevented. And for every two complications, only one case of penile cancer is prevented.
The study does not judge whether the routine but increasingly controversial procedure is appropriate, but simply provides more information for parents and physicians, said the lead researcher, Dr. Dimitri A. Christakis, a pediatrician at the University of Washington Child Health Institute.
"When parents ask me for input, I wanted to be able to present them with the risks and benefits," Christakis said. "I think different parents could look at the data and come to different conclusions."
Most complications were minor and easily treated, such as bleeding and local infection, he said. Rarer serious complications can require such things as reconstruction of the penis, he said.
The study was published in the January issue of the journal Pediatrics.
The findings came from a review of 354,297 boys born in hospitals throughout Washington state from 1987 through 1996. The study found that 37 percent were circumcised during their newborn hospital stay. That number may be low because some infants could have been circumcised later.
Circumcision of newborn boys has been routine in the United States since the 1940s because of medical, religious and social beliefs. By 1970, more than 90 percent of newborn boys were circumcised.
But it is becoming less common amid new information that its benefits are not as significant as previously believed. Today, about 65 percent of boys are circumcised in this country, the only industrialized nation where it still is routine.
Christakis said the study was prompted by the influential American Academy of Pediatrics' announcement last year that it no longer recommended routine circumcision because of questionable benefits and medical and anecdotal evidence that circumcised men have less penile sensitivity.
An estimated 1 in 100 uncircumcised boys will get a urinary tract infection in their first year, compared with 1 in 1,000 circumcised boys. Despite evidence showing penile cancer is more prevalent among uncircumcised males, the disease is so rare -- striking just 1 in 100,000 American males a year -- that researchers said the added risk is insignificant.
Christakis said the most important thing for parents to remember is that, for the vast majority of children, there is no benefit or harm from circumcision.
The leader of a national group that opposes circumcision applauded the study.
"In most countries, people don't even think about this, but here we have to educate people about a normal part of the body," said Marilyn Milos, director of the Organization of Circumcision Information Resource Centers, based in San Anselmo, Calif.