But a survey of pediatricians finds that they often fail to recognize the extra risks facing these babies.
"The trouble is that babies in this age group can have serious infections and you may not know it," says Dr. Thomas Newman, professor of pediatrics at the University of California at San Francisco and co-author of a new study into how doctors treat fever in newborns.
Pediatricians have argued for decades about the proper treatment protocol for a baby who has a temperature above 100.3 degrees Fahrenheit. Some doctors think all young babies with high fevers should undergo an extensive examination that includes urine tests and spinal taps.
The infants are especially prone to serious blood infections because their immune systems are not developed enough to limit the spread of germs to one part of the body, Newman says. For example, a urinary tract infection could spread to other organs and the bloodstream, potentially causing death.
The problem is that many babies with fevers simply have colds, he says. In those cases, full examinations aren't necessary.
"That's why this is such a hot topic," Newman says. "We're trying to figure out how can we avoid missing babies with serious infections without doing a lot of unnecessary things to everybody else."
In recent years, studies have shown that uncircumcised boys are more prone to urinary tract infections than circumcised boys, apparently because germs gather under the foreskin and make their way into the urethra and on up to the bladder, he says. It is sometimes impossible to retract the foreskin of a newborn. Girls are also more prone to infections, but not as much.
Newman and colleagues surveyed 573 pediatricians from 44 states and received reports about more than 3,000 young babies with fevers. The findings appear in the Jan. 14 issue of the Archives of Pediatrics andAdolescent Medicine.
Eighteen percent of uncircumcised boys had urinary tract infections, compared to 11 percent of the girls and 2 percent of the circumcised boys. Infections that spread to the blood were found in 2 percent of the uncircumcised boys, compared to 1.4 percent of girls and 0.3 percent of the circumcised boys. Yet only 1,775 of the babies had had their urine tested, the study says.
"The higher the fever, the more likely they are to have a urinary tract infection," Newman says. Younger babies were more prone to serious infections.
Despite the increased rates for uncircumcised boys and girls, doctors weren't more likely to test their urine, Newman says. "It apparently hadn't filtered out to pediatricians in practice."
Parents should ask about urine tests if a doctor declines to order one in the case of a baby at special risk, he says.
Dr. Paul Stricker, a pediatrician with Scripps Clinic in San Diego, says doctors may make different decisions about tests depending on the family who brings in the infant.
In a teaching hospital where he formerly worked, "it was appropriate to do more tests because we didn't know if we could rely on them coming back the next day," he says. "In the private setting, where families have a better relationship with their pediatrician they have used for years, then doing a few limited tests and following the child closely also seems to work."
What To Do
If you suspect your baby has more than a cold, ask about getting his or her urine tested -- especially if you have a son who wasn't circumcised.
According to federal statistics from 1999, an estimated 65 percent of newborn males were circumcised. For more numbers, see the National Center for Health Statistics.
Learn more about urinary tract infections and babies in this fact sheet from the UrologyChannel.