In the late 1980s to early 1990s, the city of Philadelphia was beset by an epidemic of crack-cocaine use. Anecdotal stories of the fate children exposed to cocaine while in the womb would meet as they grew into adulthood were grim. It was thought the cocaine exposure would harm their long-term development, resulting in IQs near 50, emotional issues, small heads, permanent disabilities, poor muscle tone, and tremors. They would burden school systems and be unable to hold jobs or form relationships as adults.
In the midst of this crisis, Hallam Hurt, MD, CHOP attending neonatologist, organized a team of researchers in Philadelphia and began a study funded by the National Institute on Drug Abuse, closely following more than 200 near- or full-term babies — half of whom were exposed to cocaine in utero. Almost all of the children studied were from low income families.
Children were evaluated at 6 months and then every 6 to 12 months until adulthood. Researchers tracked every aspect of a child’s development — from progress as an infant, to IQ in preschool, to analysis of the brain through MRI. They also made home visits and studied nonmedical and environmental factors in the children’s lives, including their exposure to violence.
It was one of the largest and longest running studies of in utero cocaine exposure in history. Hurt expected the findings would be consistent with anecdotes and would inform care of children exposed to cocaine before birth and possibly even guide drug-related policy.
But the study findings showed no significant differences between cocaine-exposed children and the study’s controls. Both groups scored significantly below average for developmental and intellectual measures for U.S. children in their age group, suggesting to Hurt and her team that poverty is a more powerful influence on the outcome of inner-city children than gestational exposure to cocaine.
“Because of the cogent reasons to expect problems in cocaine-exposed children, we kept looking and we looked at more and more refined evaluations,” recalls Hurt. “We continued to look for these changes and we simply didn’t find them. But what we did find was that the group as a whole was performing poorly and lagging behind.”
Hurt and her team have now begun a new study that uses MRI and other methods to study the neural and cognitive effects of poverty on infant development.
“Given what we learned, we are invested in better understanding the effects of poverty,” Hurt says. “How can early effects be detected? Which developing systems are affected? And most important, how can findings inform interventions for our children?”