written by Tara Haelle

[Note: I wrote this fairly quickly because the study was just released, but I hope to update it with more details soon.]

A new study today from JAMA Pediatrics is sure to stir up some controversy – it’s about one of those hot button topics that requires but a brief passing mention before an all-out throw-down ensues. The study reports on the rates of adverse events following circumcision, both among infants and among older children, adolescents and adults. The study is actually long overdue and is valuable because the impetus behind it centers on one of the arguments of those who oppose circumcision: that the procedure is conducted without a child’s consent and so should be postponed until the child is an adult and able to decide for themselves whether they want the procedure.

This is a reasonable argument based in fundamental principles of bioethics – those of consent and bodily integrity. However, as anyone who has observed those debates knows, the case is not so simple with circumcision, a procedure imbued with a long, complicated cultural and religious history and one which does, in fact, confer some medical benefits, albeit very small in most cases for Western, developed countries.

I do not take a public “stance” on circumcision, choosing instead to report on what we know from the research literature and analyzing the studies on it, so that’s what I’ll do here. The overall finding of this study is that adverse events resulting from the procedure occur in less than 0.5% of circumcisions, but the complication rate is far higher in older males – 20 times higher among prepubescent boys and 10 times higher in adults and boys 10 and older. The study is a solid one, but it does have a couple important weaknesses.

One of the strengths of the study is its size: the authors analyzed data from medical claims between 2001 and 2010 for 1.4 million circumcised males – about the same number who are circumcised annually in the US. The vast majority of these, 93 percent, were newborn circumcisions. Two percent included circumcisions among non-newborn infants (under 1 year old), 2% (just over 28,000) included circumcisions among boys aged 1 to 9, and 2.7% were circumcisions among males aged 10 and older (most of which were adults circumcisions). This is by far one of the largest, if not the largest, studies looking specifically at complications resulting from circumcision.

Another strength is how the researchers determined what adverse events were likely caused by the circumcision procedure. Just as adverse events following vaccination may or may not be caused by the vaccine, an adverse event following circumcision may or may not be caused by the circumcision. So the researchers set up 28-day and 1,200-day risk windows to compare the adverse events in the circumcised males with the same ones reported among approximately 1 million uncircumcised males. Out of 41 different adverse events identified by searching the medical literature, the researchers used the risk-window analysis to identify the 16 which were “probable,” that is, the ones likely caused by the circumcision.

Among newborns, these “probable” adverse events occurred with 4,059 boys, or 0.31% of circumcised newborns. (Those same probable adverse events occurred among 865 uncircumcised newborns, and we’ll get to one possible reason a bit later.) When the researchers adjusted this calculation to take into account the background rate – the rate of these adverse events that occur independently of circumcision – the rate was even lower: 0.23%.

Yet among boys aged 1 to 9, the rate of adverse events was 9.1%, and among males aged 10 and older, the rate was 5.3%. The most common complication among boys was division of penile adhesions, which occurred at a rate of 67.6 per 100,000 boys. Among males aged 10 and older, the most common complication was “inflammatory disorders of the penis,” which can include infections, cellulitis, abscess, boils, etc. These occurred at a rate of 112 per 100,000.

The stark difference in complications rates will be the source of conflict as this study is discussed because it reveals that the risk of circumcision is undoubtedly greater after infancy. However, one thing this study could not take into account were the reasons males older than 1 year old got circumcised since the study relied on medical billing codes. If the reasons for circumcision among the males were due to medical conditions that indicated circumcision, that could account at least in part for a higher risk of complications. Of course, if that is the case, it’s also possible that some of those conditions may have resulted because the boys were not circumcised as infants. It’s also unlikely that ALL of the circumcisions among adults and older boys were due to conditions medically requiring circumcision (especially given the cultural and religious reasons some individuals get circumcised), and the increased risk of complications is great enough that I would expect it still to exceed the risk of complications among newborns even after preexisting conditions were taken into account, just not by as much perhaps. Unfortunately, however, we just don’t have enough information on this. [Updated 4:20pm, starting from “However”]

This finding does not, however, mean that newborns should be circumcised – that’s still a separate risk/benefit calculation – but it does mean that the argument that a person should wait to be circumcised until old enough to give consent inherently carries more risk. The question then becomes how many men not circumcised will choose to be circumcised, something I’ve yet to research but will not doubt be brought up in discussions.

Another source of conflict may be the numbers of newborn complications themselves since they are lower than what is often cited by those who oppose circumcision. In raw number, terms, the serious complications for newborns ranged from just under 1 in a million to several hundred out of a million circumcisions. There was one case of “stricture of the male genital organs,” which means an abnormal narrowing of the urethra. On the high side, the rate of repair of incomplete circumcisions was 703 per 1 million.

I’m working on a chart that will show the rate for all the adverse events they looked at, but here are a few that particularly caught my attention. Out of 1.3 million newborns, in the 28 days following circumcision, there were the following serious probable adverse events:

3 partial amputations of the penis

293 suture laceration of the penis

4 replantation of the penis

919 repair of incomplete circumcisions

557 division of penile adhesions

757 lysis or excision of penile postcircumcision adhesions

173 cases of hemorrhage control

16 cases of suture artery

Compared to uncircumcised newborns, circumcised newborns had a higher risk for wounds, correctional procedures, inflammation and bleeding. However, the risk for surgical procedures, penile disorders and gangrene, collapsed lung and infections was higher among uncircumcised newborns.

The collapsed lung data point is interesting because it points to one possible reason for the higher risks among uncircumcised males, something called a “healthy infant bias: those newborns who undergo male circumcision are more likely to be healthier (and without such disorders) compared with their uncircumcised counterparts. (There are many possible reasons for this – not necessarily related to being circumcised or not – that we won’t go into here.)

However, this healthy bias also reveals one of the weaknesses of the study. Because the researchers relied on medical claims data, they cannot establish whether all the adverse events reported were directly related to being circumcised, directly related to being uncircumcised, or not related to circumcision status at all.

A related weakness is the fact that several of the adverse events are situations that actually might medically require a circumcision. The authors note that some of the adverse events occurred on the same day as the circumcision procedure itself, but it’s impossible to know from the data set which happened first. Obviously, a “repair of incomplete circumcision” would occur after an attempted circumcision, but other types of adverse events, they note, may have been the reason a circumcision was indicated in the first place.

Next, remember how some adverse events occurred among uncircumcised boys? In some cases, they simply experienced a medical problem with the penis that can occur regardless of circumcision status. But in other cases, those “uncircumcised” boys may actually have been circumcised outside the hospital but labeled as “uncircumcised” in the study because their record did not include a billing for circumcision. The authors attempted to make adjustments for this by reclassifying “uncircumcised” infants with a clearly circumcision-related adverse event as circumcised, but they could have missed some, which they calculated to be about 0.01% and therefore unlikely to affect the big picture.

Finally, the biggest weakness for some who read this may be this: the study was unable to report on the rate of deaths resulting from circumcision since a death doesn’t require a medical billing code. This is one of the most disputed figures in circumcision debates. I’ve been unable to find a reliable, confirmed rate because death appears to be so rare that a rate is hard to calculate. Several sources cited “no deaths” among more than 100,000 or 500,000 circumcisions. Meanwhile, the much higher rates cited on many intactivist sites (often about 2-5% and higher) are not backed up by reliable sources.

Though what I’m about to say is sure to earn me the ire of self-described intactivists, the science on circumcision’s risks and benefits is pretty equivocal. That is, the evidence does not clearly point in one direction that parents should follow. Intactivists will debate me on this point, and in doing so, they tend to betray confirmation bias because the research literature taken as a whole reveals pretty clearly that there are definite but very small medical benefits for the procedure, definite but very small risks to the procedure, and definite but very small risks to not being circumcised.

Therefore, the decision is not a scientific one. It’s an ethical and moral one. That’s not to denigrate the importance of the decision and the issues surrounding it, but using science to justify circumcising or not circumcising – excepting those cases where circumcision is actually medically indicated – is inappropriate in most cases.