Matthew L. Speltz of the University of Washington led the study comparing 235 babies recently diagnosed with flat head syndrome with 237 babies from similar backgrounds without that diagnosis. All were 4 to 12 months old. The scientists assessed motor skills and cognitive skills.

The biggest difference was seen in motor skills: 20 percent of babies with flat head syndrome had scores indicating developmental delay compared with 9 percent of babies in the control group. But the authors noted that 16 percent of babies in the general population have motor skill delays, which suggests the study may have overstated the difference.

While the study did not show that flat head syndrome caused the developmental differences, the authors encouraged pediatricians to pay close attention to the motor development of babies diagnosed with flat head syndrome. They also urged parents to find ways to vary their baby’s position during waking hours.

BOTTOM LINE: Babies who had been diagnosed with flat head syndrome scored lower on tests of motor and cognitive skills than infants without this syndrome.

CAUTIONS: This kind of study does not allow researchers to determine whether flat head syndrome caused the apparent developmental delays, nor can it rule out the possibility that motor and cognitive delays caused children to have flat heads from staying in one position.

WHAT’S NEXT: The researchers will test the babies when they are 18 and 36 months old to see whether differences persist.

WHERE TO FIND IT: Pediatrics, online Feb. 15