Cocaine and making children do not combine. It's clear that maternal drug can induce lasting effects on children.

A new research reveals that young schoolchildren of cocaine-using mothers performed more poorly on attention tests. The investigation was made on 415 African-American children when aged 5 or 7 (now 14 to 16 years old) from a poor population living in the Miami inner city.

219 of the children had mothers who had taken cocaine while pregnant, while the others 196 had not. Those born to cocaine-addicted mothers presented more trouble paying attention than the other kids and were more likely to commit omission errors. They also displayed slower reaction times when put to solve different tasks.

"This study provides further evidence of a subtle but consistent effect on attention through early school-aged years," said lead author Veronica Accornero, assistant professor of clinical pediatrics at the University of Miami.

Still, these effects are significantly weaker than those induced by alcohol and tobacco consume.

"Children born to cocaine-using mothers are doing much better than anyone predicted, especially considering their background," said Tamara Warner, research assistant professor at the University of Florida.

There was a general concern after the crack epidemic of the 1980s, about the future of the so-called "crack babies". But the general effects "appear to be more subtle and specific than initially believed," Accornero further said.

"The children do not appear to have a hard time with "intellectual functioning," although they might have difficulties with language, attention and behavior. Certainly, attention and the ability to maintain attention is an important skill that supports the development of other skills like language and behavior," Accornero concluded.

"It's possible that because of subtle deficits we may see an effect on academic performance."