A recently released report from the Centers for Disease Control and Prevention’s National Center for Health Statistics finds that the rate of newborn male circumcision has varied over the past three decades but that overall it’s down by about 10 percent. The report does not posit reasons for this trend, but public health experts have suggested it may be a result of changes in medical opinions, public opinions, and insurance coverage.

The report is based on data collected from 450 hospitals across the country between 1979 and 2010. It found that in 2010, 58.3 percent of newborn males were circumcised in the hospital compared to 64.5 percent of newborn males in 1979. Circumcision rates were highest in 1981, at 64.9 percent, and lowest in 2007, at 55.4 percent.

It is important to note that the report only includes those circumcisions that were performed during an infant’s newborn stay in the hospital. It does not include any procedures conducted by pediatricians or clinic staff after the baby is released from the hospital, nor does it include any circumcisions performed as part of religious ceremonies, which are common in both the Jewish and Muslim communities. Some experts suggest that the numbers in the report may be lower than the actual rates because as hospital stays after birth have become shorter, offsite circumcisions are more common. Douglas Diekema of the Treuman Katz Center for Pediatric Bioethics at Seattle Children’s Research Institute told USA Today, “Often they’re going home within 24 hours, so in some places, these procedures are increasingly being done by the pediatrician during the follow-up period in the doctor’s office or clinic as opposed to the hospital.”

The authors of the report did not try to explain the trends but did note that the rates may correspond with the official medical recommendations from the American Academy of Pediatrics (AAP), which have changed five times in the last 32 years. In 1971, an AAP task force released a report saying there was no evidence that routine circumcision of newborn males was necessary. A 1975 report came to a similar conclusion. But the AAP began revising its opinion in 1989 when it published a report citing some health benefits of the procedure. A 1999 report again concluded that there was evidence of health benefits—including lower rates of urinary tract infections and sexually transmitted diseases—but seemed hesitant to even appear to be promoting the procedure. The authors of that report wrote, “As in any circumstance in which there are potential benefits and risks, yet the procedure is not essential to the child’s current well-being, parents should determine what is in the best interest of the child.”

The AAP did not revisit the issue until August of 2012, when it again compiled the current evidence about health benefits of circumcision. In a 23-page report, the task force examined a number of studies conducted between 1995 and 2010, which found that circumcision could prevent urinary tract infections, HIV, human papillomavirus (HPV), genital herpes, and penile cancer. This most recent opinion is much more supportive of circumcision. As Rewire reported at the time, some even called it an endorsement of the procedure. Still, the AAP stopped short of recommending routine circumcision for newborn males, saying instead, “Evaluation of current evidence indicates that the health benefits of newborn male circumcision outweigh the risks and that the procedure’s benefits justify access to this procedure for families who choose it.”

Parents may be following this medical advice or they be swayed by public opinion and standard practice in their area. The data also shows wide variations between regions in the United States. Newborn circumcision rates were flat in the Northeast, where they were at their highest in 1994 (69.6 percent) and lowest in 2007 (60.7 percent), but fell by more than 37 percent in the West, where only 40.2 percent of newborns were circumcised in 2010. Most of this drop occurred in the 1980s as the rates dropped from 63.9 percent in 1979 to 41.0 percent in 1989; but the lowest circumcision rates in the West were actually seen in 2003, when just 31.4 percent of newborn males were circumcised. In the South, rates of newborn circumcision went in the opposite direction in 1980s—increasing between 1979 and 1998 and then declining. In 2010, 58.4 percent of newborn males in the South were circumcised. Finally, rates in the Midwest were ranged from a high of 82.9 percent of males in 1998 to a low of 68.8 percent in 2009.

Some of this variation may be explained by the religious and cultural makeup of various areas. For example, seven of the eight “most Jewish” states (those in which more than 0.6 percent of the population identifies as Jewish) are in the Northeast where circumcision rates have remained consistently higher than elsewhere. Similarly, some note that an influx of immigrants to the West Coast from countries that don’t practice circumcision may explain the diminishing rates in that area. Politics and activism may also be at play on the West Coast. Led by opponents of circumcision, who refer to themselves as “intactivists,” two California cities (San Francisco and Santa Monica) went as far as to consider ballot measures to ban the procedure altogether. Such ballot measures, however, are no longer a possibility; Gov. Jerry Brown signed a “ban on bans” in 2011.

Another explanation for dropping circumcision rates has to do with insurance coverage. As Rewire reported last summer, coverage by private insurers varies widely, and there is a trend among state Medicaid programs to stop paying for the procedure. To date, at least 18 state Medicaid programs have stopped covering it, and there is strong evidence that this does affect how many newborns are circumcised in a state. For example, Arizona decided to eliminate coverage for the procedure in 2002 in order to save the state approximately $400,000 per year. The circumcision rate in that state dropped from 41 percent in 2002 to 21 percent in 2004. In fact, a report by the Healthcare Cost and Utilization Project found that circumcision rates are 24 percent higher in states where Medicaid covers the procedure.

A 2012 study, published by Archives of Pediatric and Adolescent Medicine, suggests that cutting coverage for circumcision is not cost effective in the long run. Conducted by public health experts and economists at the Johns Hopkins University School of Medicine, the study found that if circumcision rates in the United States were to fall to the same levels as in Europe (where only about 10 percent of newborn males are circumcised), we could face more than $4 billion in increased health-care costs over a decade to pay for treatment of urinary tract infections, syphilis, herpes, penile cancer, and HIV.

The data presented in the new report only goes through 2010, which is before the AAP released its most recent recommendations on the subject. As explained earlier, these new recommendations are much more supportive of the procedure. Moreover, the AAP Task Force specifically called on insurers to make the procedure available to parents. Douglas Diekema, who is a member of the task force, explained at the time of the report’s release, “The tone of the policy certainly shifts somewhat in favor of circumcision in that it recognizes that there are clear medical benefits that outweigh the risks of the procedure, and that those benefits are sufficient to justify coverage by insurance.”

It will be interesting to see if the new support from the AAP reverses the trend both in Medicaid coverage and in newborn circumcision itself.