(Reuters Health) - Even though infant and child mortality rates in wealthy nations have been steadily declining for decades, American children are still more likely to die than kids in other affluent countries, a U.S. study suggests.

Back in the early 1960s, infant and child mortality rates were similar for the U.S. and 19 other countries with comparable levels of economic development. But as these rates began falling in the late 60s, the U.S. lagged. By the 1980s, U.S. child mortality was 30 percent higher compared to the other 19 nations. By the first decade of this century, the risk of death for infants was 76 percent higher in the U.S., and for children aged 1 to 19 the risk of death was 57 percent higher.

“We were surprised by how far the U.S. has fallen behind other wealthy countries: across all ages and in both sexes, children have been dying more often in the U.S. than in similar countries since the 1980s,” said lead study author Dr. Ashish Thakrar of the Johns Hopkins Hospital and Health System in Baltimore.

“We were also surprised by how much more often U.S. adolescents, in particular boys, are dying from injuries,” Thakrar said by email. “U.S. teens are dying at 3 times the rate of other countries from motor vehicle accidents and 82 times the rate of teens from other countries due to gun violence.”

For the study, researchers compared mortality rates for infants and children in the U.S. to their counterparts in Australia, Austria, Belgium, Canada, Denmark, Finland, France, Germany, Iceland, Ireland, Italy, Japan, the Netherlands, New Zealand, Norway, Spain, Sweden, Switzerland and the United Kingdom.

Persistently high poverty rates, poor educational outcomes and a relatively weak social safety net have contributed to the U.S. having worse infant and child mortality rates than any of these other nations, researchers write in Health Affairs.

The leading cause of infant mortality was extreme prematurity, a problem that may be at least in part a byproduct of rising rates of obesity and an increasing number of women choosing to start families later in life, when their risk of pregnancy complications is greater. The risk is also higher for women who don’t receive good prenatal care.

“Preventive screening and services designed to reduce modifiable risk factors before the pregnancy, referred to as preconception care, can make an important difference in improving pregnancy outcomes and maternal and child health,” said Dana Schultz, a policy researcher at RAND Corporation in Pittsburgh, Pennsylvania.

“Those planning a family need to pay attention to potential environmental hazards as well as nutrition, weight management, substance use, medical conditions and mental health before moving down the path toward parenthood,” Shultz, who wasn’t involved in the study, said by email.

With older children, aged 15 to 19 years, gun homicides, car crashes and other accidents and injuries appear to be driving the worse mortality rates in the U.S., the study results suggest.

“To be sure, antisocial behavior tends to rise to a peak in the mid to late adolescent years,” said Alex Piquero, a criminology researcher at the University of Texas at Dallas who wasn’t involved in the study.

“When that reality is coupled with easy access to guns, motor vehicles, group-oriented misbehavior and potentially illegal substances, there is a perfect storm of many risk factors that coincide and congeal simultaneously to increase risky behavior and adverse outcomes,” Piquero said by email.

SOURCE: bit.ly/2CH2ueL Health Affairs, online January 1, 2018.