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Case epidemiologist reports IQ decreases in cocaine-exposed babies with anemia

Another strike against cocaine use by expectant mothers using cocaine has surfaced.

Suchitra Nelson, an epidemiologist in the Case Western Reserve University School of Dental Medicine, reports in a recent issue of Development and Behavioral Pediatrics that prenatal cocaine-exposed babies are more likely to have iron-deficiency anemia, which leads to a two-fold decrease in their IQ scores when compared with cocaine-exposed babies without anemia.

She found that the cocaine-exposed babies with anemia were at greater risk for long-term cognitive and motor skill problems by the age of four.

"These cocaine exposed children when compared to unexposed children at 2 and 4 years old have higher levels of anemia than unexposed children. They also tested for more anemia than the national average for children, which increases their risks for cognitive development problems," said Nelson, an assistant professor in the department of community dentistry at the Case dental school.

She reported the study's findings in the article, "Cocaine, Anemia, and Neurodevelopmental Outcomes in Children: A Longitudinal Study."

Iron is critical for brain development between birth and 2 years old. Iron deficiency anemia in babies can result in impairments to the neurotransmitters, which produce verbal and thinking skills.

Nelson and a team of Case researchers looked at the impact of iron-deficiency anemia and high lead levels on 2- and 4-year olds participating in a longitudinal study of the impact of prenatal cocaine exposure on children.

Lynn Singer from the department of pediatrics at the Case School of Medicine-and a co-investigator on the anemia study-began the cocaine baby study in 1994 and has followed the children for the past decade. Other researchers working with Nelson and Singer were Edith Lerner from the department of nutrition and Robert Needlman and Ann Salvator from the pediatrics department, both at Case's medical school.

Nelson's study sample included 143 2-year olds (70 cocaine exposed and 73 unexposed children) and 274 4-year olds (139 exposed and 135 unexposed) from impoverished backgrounds where mothers lacked advance education and where the home environments made the children vulnerable to poor diets and the stresses of lower socioeconomic conditions.

The researchers also examined if high levels of lead in the blood contributed cognitive impairments, which results from children eating paint chips and other non-food substances from lead-based paint that still is prevalent in older and poorer neighborhoods. Lead poisoning was ruled out as a factor after the children tested to have similar lead levels of lead in their blood.

Nelson then focused on blood-iron levels. Because cocaine-exposed children with an iron deficiency, but not at the level of anemia, showed no difference in cognitive and motor skill scores on IQ and other test measurements, she combined those children with the unexposed group.

Nelson suspects that the chronic anemia of the cocaine-exposed baby may be a result of their low weight or premature births to malnourished mothers. Premature birth places children at greater risk for anemia. As the baby develops, iron stores get depleted faster during prenatal development.

As a result of the study, Nelson calls for a greater awareness on the part of pediatricians to monitor blood-iron levels in cocaine-exposed babies. In the interest of public health, she also says there is a need for more studies that target appropriate screening and intervention strategies.


About Case Western Reserve University

Case is among the nation's leading research institutions. Founded in 1826 and shaped by the unique merger of the Case Institute of Technology and Western Reserve University, Case is distinguished by its strengths in education, research, service, and experiential learning. Located in Cleveland, Case offers nationally recognized programs in the Arts and Sciences, Dental Medicine, Engineering, Law, Management, Medicine, Nursing, and Social Work.