A new sub-specialty of doctors — child abuse pediatricians — are certified as experts in determining whether a broken bone or a bruise is accidental or intentional.

Emma Lee/Life File / Photodisc / Getty Images

Child abuse is a persistent problem in this country. Research published in February in Pediatrics found that child abuse kills 300 kids under 18 each year and accounts for 58.2 hospitalizations of babies per 100,000 births — more than the annual rate of SIDS. Another recent study made the case that child abuse sets the stage for future mental illness.

For a pediatrician, it can be dicey sussing out whether a child came by a broken bone or a bruise naturally or whether the injury was inflicted by an adult. As of 2009, there is an entirely new specialty devoted to making those types of assessments: the board-certified child abuse pediatrician, who focuses on identifying child maltreatment and neglect.

(MORE: How Child Abuse Primes the Brain for Future Mental Illness)

The small but growing specialty is getting a promotional boost this month — which is Child Abuse Prevention Month — from Dr. Robert Block, president of the American Academy of Pediatrics (AAP). Block was part of a group of pediatricians who first started talking about the need for a sub-specialty about 20 years ago. It took about a decade to gather enough supporting evidence to present a proposal to the American Board of Pediatrics, which wasn’t sufficiently persuaded. In 2006, after supporters collected more data, the Board changed its no to a yes, and child abuse pediatrics became an official sub-specialty.

The first certification exam was administered in 2009, and about 180 pediatricians passed. Part of their mission is to advocate for better parenting education initiatives, such as parenting-skills classes in high schools. But with limited resources, schools haven’t been lining up to teach how to soothe a crying baby — though, arguably, the skill will be far more relevant than, say, AP calculus to most high-schoolers down the line.

You have to pass a test to drive a car or to become an American citizen, but there’s no exam required to become a parent. And yet child abuse can stem from a lack of awareness about child development.

(MORE: Nurturing Moms May Boost Children’s Brain Growth)

“If parents understand the challenges and understand that temper-tantrum behavior is perfectly normal in young kids and there are ways to handle that, they will have better success,” says Block. “Child abuse pediatricians are very much interested in prevention. But we seem to be not very interested as a country in teaching parenting skills.”

It’s critical, though, because parents are usually the ones who abuse their children. We wrote about the Pediatrics study in February:

Previous research has found that parents — and occasionally babysitters — are the ones who lose control. Of parents, men — fathers, stepfathers and boyfriends — are the largest single group of perpetrators. Researchers at Yale University found that abuse landed 4,569 children under 18 in the hospital in 2006; 300 of them died. The death rate — 6% — was substantially higher than for children who were admitted for other kinds of injuries or medical or surgical problems.

Of course, there exists a minority of what Block terms “really evil people, the kind who lock their kids in closets.” And sex abusers are another breed altogether; they’re intent on harming kids. But most child abusers simply snap from the stress of parenting, coupled with the stress of everyday life — a lost job, perhaps, or a foreclosed home.

Although some studies have found that child abuse is on the decline, most child abuse pediatricians disagree. Various states report their data differently, and some don’t submit regular reports.

(MORE: Study: Child Abuse Affects More U.S. Kids than SIDS)

There’s more than enough work for the 250 or so child abuse pediatricians in the U.S. As the experts in the field, they’ve essentially been deputized as detectives of neglect. They’re available to consult with other physicians who aren’t sure whether what they’re seeing looks suspiciously like abuse or neglect; while most injuries are indeed accidental, every state requires pediatricians to report abuse — even in cases where they’re not certain — to authorities. “You don’t always know,” says Block. “Sometimes you just can’t be definite. It’s a very sticky wicket for pediatricians.”