By the late 1980s, medical professionals in Philadelphia were concerned the city had a crack cocaine epidemic. One in 6 children born at the city hospital had mothers who tested positive for cocaine. Curious about just how harmful cocaine was for the long-term development of children who had been exposed to the drug in their mother’s womb, Hallam Hurt, former chair of neonatology at Albert Einstein Medical Center, began a study in which he evaluated the effects of in-utero cocaine exposure on children.

Hurt found 224 children who were born at the hospital between 1989 and 1992. Half of the children had mothers who used cocaine while they were pregnant. All came from low-income families, and almost all were Black.

One participant in the study, Karen Drakewood, says she was on an all-night crack binge when she went into labor with her now-23-year-old daughter Jaimee.

“Jaimee was beautiful when she was born. A head full of hair. She looked like a porcelain doll,” Drakewood, now 51, said to the Philadelphia Inquirer. “She was perfect.”

“My worst fear was that Jaimee would be slow, mentally retarded, or something like that because of me doing drugs,” Drakewood said, adding that she decided to enroll in the study for the sake of Jaimee and her older daughter, but eventually began smoking crack again.

Researchers have been tracking Jaimee’s development since birth to see how she was affected by her mother’s use of crack. They have gauged her progress as an infant, measured her IQ, and examined her brain development with an MRI.

When Hurt first began the study, she said there was a lot of buzz circulating that “crack babies” had small heads, were easily agitated, prone to tremors, had bad muscle tone, were aloof and avoided eye contact.

“We went looking for the effects of cocaine,” she said.

But after finding no significant difference between the cocaine-exposed children and the control group when it came to IQ or school readiness, “We began to ask, ‘Was there something else going on?’” she said.

In May, Hurt, now a professor of pediatrics at the University of Pennsylvania, shared her findings, which make up the largest and longest-running federally funded study on in-utero cocaine exposure. She said that living in poverty was much more destructive for a child than being exposed to cocaine in their mother’s womb.

“Given what we learned,” Hurt said, “we are invested in better understanding the effects of poverty. How can early effects be detected? Which developing systems are affected? And most important, how can findings inform interventions for our children?”

Hurt’s work is not the only research that has found poverty is more harmful for the health and well-being of a child than cocaine. Claire Coles, a psychiatry professor at Emory University, said she has been following a group of low-income children in Atlanta for years, and has found, like Hurt, that cocaine exposure doesn’t seem to affect children’s overall cognition and school performance. However, children who are living in stressful environment — such as poverty — are affected when it comes to learning and their emotional health.

“As a society we say, ‘Cocaine is bad and therefore it must cause damage to babies,'” Coles said to the Inquirer. “When you have a myth, it tends to linger for a long time.”

Deborah A. Frank, a pediatrics professor at Boston University who has also studied in-utero exposure to cocaine, agrees with Hurt’s findings.

“As rates of cocaine addiction soared in the late 1980s and early 1990s, the media described these children as ‘doomed,’ a biological underclass of children unable to learn or love,” she said to ABC News.

“You can’t walk into a classroom and tell this kid was exposed and this kid was not,” Frank told the Inquirer. “Unfortunately, there are so many factors that affect poor kids. They have to deal with so much stress and deprivation. We have also found that exposure to violence is a huge factor.”

While Frank, Hurt and Coles say that cocaine still isn’t good for babies and pregnant mothers should not consume the drug, they stress that exposure to cocaine in utero doesn’t mean that child will grow up to be an addict or a criminal.

“Some kids have stunned us with how well they’ve done,” Frank said.

According to a July 2013 study from researchers at Harvard University and the University of California-Berkeley, very few children who are born into poverty are able to earn financial success later in life — despite the efforts of government programs designed to encourage upward mobility.

According to the study, children in some areas — such as New York, Boston, and cities in California — have more opportunities that allow them to get out of poverty than those living in the Midwest or southeastern United States. Even so, education and family structure still play a large role in determining whether a child will be able to escape poverty.

According to an interactive map on The New York Times website that was created based on the researchers’ findings, children growing up in poverty in Philadelphia have about a 26 percent chance of earning an income that is higher than the poverty level.

However, race also played a role, as did the question of whether a child was raised in a two-parent household, the quality of their education, and whether they were involved with any religious or community groups.