Individuals who receive a blow to the head may be at risk of developing a traumatic brain injury (TBI), which can lead to everything from permanent disability to death, according to the Centers for Disease Control and Prevention. In addition, approximately 1.7 million people sustain this type of injury on an annual basis.

Now, new research has shown that TBIs that occur early on may lead to trouble with people’s cognitive development and intellectual ability later in life, CNN reported. These are the findings of two recent studies, which both appear in the journal Pediatrics.

In the first study, researchers looked at the intellectual, social and behavioral functions of 53 children who had sustained TBIs before the age of 3, with 27 youths who did not, the news source stated. Severe TBIs were found to reduce intellectual function.

The second study involved 40 children who sustained TBIs between the ages of 2 and 7, according to the news outlet. Those with the most severe injuries struggled to keep up with their peers in terms of intellectual development.

Based on these findings, parents of children who have sustained TBIs may want to have them complete a kids IQ test to see how well their cognitive abilities are developing as they age.